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[Illustration]




SCIENTIFIC AMERICAN SUPPLEMENT NO. 344




NEW YORK, August 5, 1882

Scientific American Supplement. Vol. XIV, No. 344.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.


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TABLE OF CONTENTS.

I.   ENGINEERING AND MECHANICS.--The Panama Canal. By
     MANUEL EISSLER. I.--Historical notes.--Spanish Discoveries
     in Central America.--Early explorations.--Nicaragua
     projects.--Panama railway, etc.

     Improved Averaging Machine.

     Compound Beam Engine. 4 figures.--Borsig's improved
     compound beam engine.

     Power Hammers with Movable Fulcrum.--By DANIEL
     LONGWORTH. 5 figures.

     The Bicheroux System of Furnaces Applied to the Puddling of
     Iron. 2 figures.

     Gessner's Continuous Cloth Pressing Machine. 3 figures.

     Novelties in Ring Spindles. 4 figures.

     Improvements in Woolen Carding Engines.

II.  NATURAL HISTORY.--Metamorphosis of the Deer's
     Antlers.--Annual changes. 9 figures.

     Monkeys. By A.R. WALLACE.--Comparison of skeletons of man,
     orang outang, and chimpanzee.--Other anatomical resemblances
     and diversities.--The different kinds of monkeys and the
     countries they inhabit.--American monkeys.--Lemurs.
     --Distribution, affinities, and zoological rank of monkeys.

     Silk Producing Bombyces and other Lepidoptera reared in
     1881. By ALFRED WAILLY, Member Lauriat de la Societe
     d'Acclimatation de France.--An extended and important
     European, Asiatic, and American silk worms, and other
     silk producers.

III. MINERALOGY, METALLURGY, ETC.--The Mineralogical
     Localities In and Around New York City and the Minerals
     Occurring Therein.--By NELSON H. DARTON.--Chances for
     collecting within one hour's ride of New York.--Methods
     of collecting and testing.--Localities on Bergen
     Hill.--The Weehawken Tunnel.--Minerals and modes of
     occurrence.--Calcite.--Natrolite.--Pectolite.--Datholite.
     --Apopholite.--Phrenite.--Iron and copper pyrites.
     --Stilbite.--Laumonite.--Heulandite.

     Antiseptics.

     Crystallization and its Effects Upon Iron. By N.B. WOOD.--
     Beauty of Crystals.--Nature of cohesion.--Cleavage.--Growth
     of crystals.--Some large crystals.--Cast iron.--Influence
     of phosphorus and sulphur.--Nature of steel.--Burnt
     steel.--Effect of annealing.

IV.  ARCHITECTURE, ART, ETC.--The Cathedral of Burgos, Spain.
     --Full page illustration from photograph.

     Description of Burgos Cathedral.

     Photo-Engraving on Zinc and Copper. By LEON VIDAL.

     Meridian Line.--A surveyor's method of finding the true
     meridian.--By R.W. MCFARLAND.

V.   ELECTRICITY, ETC.--Electro Mania. By W. MATTIEU
     WILLIAMS.--Example of electrical exaggeration and
     delusion.--Early scientific attempts at electro-motors,
     electric lamps, etc.

     Action of Magnets Upon the Voltaic Arc. By TH. DU
     MONCEL. 2 figures.

     Volckmar's Secondary Batteries.

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METAMORPHOSIS OF THE DEER'S ANTLERS.


Every year in March the deer loses its antlers, and fresh ones
immediately begin to grow, which exceed in size those that have just
been lost. Few persons probably have been able to watch and observe the
habits of the animal after it has lost its antlers. It will, therefore,
be of interest to examine the accompanying drawings, by Mr. L. Beckmann,
one of them showing a deer while shedding its antlers, and the other
as the animal appears after losing them. In the first illustration the
animal has just lost one of its antlers, and fright and pain cause it
to throw its head upward and become disturbed and uneasy. The remaining
antler draws down one side of the head and is very inconvenient for the
animal. The remaining antler becomes soon detached from its base,
and the deer turns--as if ashamed of having lost its ornament and
weapon--lowers its head, and sorrowfully moves to the adjoining thicket,
where it hides. A friend once observed a deer losing its antlers, but
the circumstances were somewhat different. The animal was jumping over a
ditch, and as soon as it touched the further bank it jumped high in the
air, arched its back, bent its head to one side in the manner of an
animal that has been wounded, and then sadly approached the nearest
thicket, in the same manner as the artist has represented in the
accompanying picture. Both antlers dropped off and fell into the ditch.

[Illustration: METAMORPHOSIS OF DEER'S ANTLERS.--FIRST STAGE.]

Strong antlers are generally found together, but weak ones are lost at
intervals of two or three days. A few days after this loss the stumps
upon which the antlers rested are covered with a skin, which grows
upward very rapidly, and under which the fresh antlers are formed, so
that by the end of July the bucks have new and strong antlers, from
which they remove the fine hairy covering by rubbing them against young
trees. It is peculiar that the huntsman, who knows everything in regard
to deer, and has seventy-two signs by which he can tell whether a male
or female deer passes through the woods, does not know at what age the
deer gets its first antlers and how the antlers indicate the age of the
animal. Prof. Altum, in Eberswalde, has given some valuable information
in regard to the relation between the age of the deer and the forms of
their antlers, but in some respects he has not expressed himself very
clearly, and I think that my observations given in addition to his may
be of importance. When the animal is a year old--that is, in June--the
burrs of the antlers begin to form, and in July the animal has two
protuberances of the size of walnuts, from which the first branches of
the antlers rise; these branches having the length of a finger only, or
being even shorter, as shown at 1, in diagram, on p. 5481. After the
second year more branches are formed, which are considerably longer and
much rougher at the lower ends than the first. The third pair of antlers
is different from its predecessors, inasmuch as it has "roses," that is,
annular ridges around the bases of the horn, which latter are now bent
in the shape of a crescent. Either the antler has a single branch (Fig.
3, _a_), or besides the point it has another short end, which is a most
rare shape, and is known as a "fork" (Fig. 3, _b_), or it has two forks
(Fig. 3, _c_). In the following year the antlers take the form shown
in Fig. 4, and then follows the antler shown in Fig. 5, _a_, which
generally has "forks" in place of points, and is known as forked antler
in contradistinction to the point antler shown in Fig. 5, _b_, which
retains the shape of the antler, Fig. 4, but has additional or
intermediate prongs or branches. The huntsmen designate the antlers by
the number of ends or points on the two antlers. For instance, Fig. 4 is
a six-ender; Fig. 5 shows an eight-ender, etc.; and antlers have been
known to have as many as twenty-two ends. If the two antlers do not
have the same number of ends the number of ends on the larger antler
is multiplied by two and the word "odd" is placed before the word
designating the number of ends. For instance, if one antler has
three ends and the other four, the antler would be termed an "odd"
eight-ender. The sixth antler shown in Fig. 6 is a ten-ender, and
appears in two different forms, either with a fork at the upper end, as
shown in Fig. 6, _a_, or with a crown, as shown in Fig. 6, _b_. In Fig.
7 an antler is shown which the animal carries from its seventh year
until the month of March of its eighth year. From that time on the
crowns only increase and change. The increase in the number of points is
not always as regular as I have described it, for in years when food
is scarce and poor the antlers are weak and small, and when food is
plentiful and rich the antlers grow exceedingly large, and sometimes
skip an entire year's growth.--_Karl Brandt, in Leipziger lllustrirte
Zeitung_.

[Illustration: METAMORPHOSIS OF DEER'S ANTLERS.--SECOND STAGE.]

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MONKEYS.

By ALFRED R. WALLACE.


If the skeleton of an orang-outang and a chimpanzee be compared with
that of a man, there will be found to be the most wonderful resemblance,
together with a very marked diversity. Bone for bone, throughout the
whole structure, will be found to agree in general form, position, and
function, the only absolute differences being that the orang has nine
wrist bones, whereas man and the chimpanzee have but eight; and the
chimpanzee has thirteen pairs of ribs, whereas the orang, like man, has
but twelve. With these two exceptions, the differences are those of
shape, proportion, and direction only, though the resulting differences
in the external form and motions are very considerable. The greatest of
these are, that the feet of the anthropoid or man-like apes, as well as
those of all monkeys, are formed like hands, with large opposable thumbs
fitted to grasp the branches of trees, but unsuitable for erect walking,
while the hands have weak, small thumbs, but very long and powerful
fingers, forming a hook, rather than a hand, adapted for climbing up
trees and suspending the whole weight from horizontal branches. The
almost complete identity of the skeleton, however, and the close
similarity of the muscles and of all the internal organs, have produced
that striking and ludicrous resemblance to man, which every one
recognizes in these higher apes, and, in a less degree, in the whole
monkey tribe; the face and features, the motions, attitudes, and
gestures being often a strange caricature of humanity. Let us, then,
examine a little more closely in what the resemblance consists, and how
far, and to what extent, these animals really differ from us.

Besides the face, which is often wonderfully human--although the absence
of any protuberant nose gives it often a curiously infantile aspect,
monkeys, and especially apes, resemble us most closely in the hand and
arm. The hand has well-formed fingers, with nails, and the skin of the
palm is lined and furrowed like our own. The thumb is, however, smaller
and weaker than ours, and is not so much used in taking hold of
anything. The monkey's hand is, therefore, not so well adapted as that
of man for a variety of purposes, and cannot be applied with such
precision in holding small objects, while it is unsuitable for
performing delicate operations, such as tying a knot or writing with a
pen. A monkey does not take hold of a nut with its forefinger and thumb,
as we do, but grasps it between the fingers and the palm in a clumsy
way, just as a baby does before it has acquired the proper use of
its hand. Two groups of monkeys--one in Africa and one in South
America--have no thumbs on their hands, and yet they do not seem to be
in any respect inferior to other kinds which possess it. In most of the
American monkeys the thumb bends in the same direction as the fingers,
and in none is it so perfectly opposed to the fingers as our thumbs are;
and all these circumstances show that the hand of the monkey is, both
structurally and functionally, a very different and very inferior organ
to that of man, since it is not applied to similar purposes, nor is it
capable of being so applied.

When we look at the feet of monkeys we find a still greater difference,
for these have much larger and more opposable thumbs, and are therefore
more like our hands; and this is the case with all monkeys, so that even
those which have no thumbs on their hands, or have them small and weak
and parallel to the fingers, have always large and well-formed thumbs on
their feet. It was on account of this peculiarity that the great French
naturalist Cuvier named the whole group of monkeys Quadrumana, or
four-handed animals, because, besides the two hands on their fore-limbs,
they have also two hands in place of feet on their hind-limbs. Modern
naturalists have given up the use of this term, because they say that
the hind extremities of all monkeys are really feet, only these feet
are shaped like hands; but this is a point of anatomy, or rather of
nomenclature, which we need not here discuss.

Let us, however, before going further, inquire into the purpose and
use of this peculiarity, and we shall then see that it is simply an
adaptation to the mode of life of the animals which possess it. Monkeys,
as a rule, live in trees, and are especially abundant in the great
tropical forests. They feed chiefly upon fruits, and occasionally eat
insects and birds'-eggs, as well as young birds, all of which they find
in the trees; and, as they have no occasion to come down to the ground,
they travel from tree to tree by jumping or swinging, and thus pass the
greater part of their lives entirely among the leafy branches of lofty
trees. For such a mode of existence, they require to be able to move
with perfect ease upon large or small branches, and to climb up rapidly
from one bough to another. As they use their hands for gathering fruit
and catching insects or birds, they require some means of holding on
with their feet, otherwise they would be liable to continual falls, and
they are able to do this by means of their long finger-like toes and
large opposable thumbs, which grasp a branch almost as securely as a
bird grasps its perch. The true hands, on the contrary, are used chiefly
to climb with, and to swing the whole weight of the body from one branch
or one tree to another, and for this purpose the fingers are very long
and strong, and in many species they are further strengthened by being
partially joined together, as if the skin of our fingers grew together
as far as the knuckles. This shows that the separate action of the
fingers, which is so important to us, is little required by monkeys,
whose hand is really an organ for climbing and seizing food, while their
foot is required to support them firmly in any position on the branches
of trees, and for this purpose it has become modified into a large and
powerful grasping hand.

Another striking difference between monkeys and men is that the former
never walk with ease in an erect posture, but always use their arms in
climbing or in walking on all-fours like most quadrupeds. The monkeys
that we see in the streets dressed up and walking erect, only do so
after much drilling and teaching, just as dogs may be taught to walk in
the same way; and the posture is almost as unnatural to the one animal
as it is to the other. The largest and most man-like of the apes--the
gorilla, chimpanzee, and orang-outang--also walk usually on all-fours;
but in these the arms are so long and the legs so short that the body
appears half erect when walking; and they have the habit of resting on
the knuckles of the hands, not on the palms like the smaller monkeys,
whose arms and legs are more nearly of an equal length, which tends
still further to give them a semi-erect position. Still they are never
known to walk of their own accord on their hind legs only, though they
can do so for short distances, and the story of their using a stick and
walking erect by its help in the wild state is not true. Monkeys, then,
are both four-handed and four-footed beasts; they possess four hands
formed very much like our hands, and capable of picking up or holding
any small object in the same manner; but they are also four-footed,
because they use all four limbs for the purpose of walking, running, or
climbing; and, being adapted to this double purpose, the hands want the
delicacy of touch and the freedom as well as the precision of movement
which ours possess. Man alone is so constructed that he walks erect with
perfect ease, and has his hands free for any use to which he wishes
to apply them; and this is the great and essential bodily distinction
between monkeys and men.

We will now give some account of the different kinds of monkeys and the
countries they inhabit.


THE DIFFERENT KINDS OF MONKEYS AND THE COUNTRIES THEY INHABIT.

Monkeys are usually divided into three kinds--apes, monkeys, and
baboons; but these do not include the American monkeys, which are really
more different from all those of the Old World than any of the
latter are from each other. Naturalists, therefore, divide the whole
monkey-tribe into two great families, inhabiting the Old and the New
World respectively; and, if we learn to remember the kind of differences
by which these several groups are distinguished, we shall be able
to understand something of the classification of animals, and the
difference between important and unimportant characters.

Taking first the Old World groups, they may be thus defined: apes have
no tails; monkeys have tails, which are usually long; while baboons have
short tails, and their faces, instead of being round and with a man-like
expression as in apes and monkeys, are long and more dog-like. These
differences are, however, by no means constant, and it is often
difficult to tell whether an animal should be classed as an ape, a
monkey, or a baboon. The Gibraltar ape, for example, though it has no
tail, is really a monkey, because it has callosities, or hard pads of
bare skin on which it sits, and cheek pouches in which it can stow away
food; the latter character being always absent in the true apes, while
both are present in most monkeys and baboons. All these animals,
however, from the largest ape to the smallest monkey, have the same
number of teeth as we have, and they are arranged in a similar manner,
although the tusks or canine teeth of the males are often large, like
those of a dog.

The American monkeys, on the other hand, with the exception of the
marmosets, have four additional grinding teeth (one in each jaw on
either side), and none of them have callosities, or cheek pouches. They
never have prominent snouts like the baboons; their nostrils are placed
wide apart and open sideways on the face; the tail, though sometimes
short, is never quite absent; and the thumb bends the same way as the
fingers, is generally very short and weak, and is often quite wanting.
We thus see that these American monkeys differ in a great number of
characters from those of the Eastern hemisphere; and they have this
further peculiarity, that many of them have prehensile or grasping
tails, which are never found in the monkeys of any other country.
This curious organ serves the purpose of a fifth hand. It has so much
muscular power that the animal can hang by it easily with the tip curled
round a branch, while it can also be used to pick up small objects with
almost as much ease and exactness as an elephant's trunk. In those
species which have it most perfectly formed it is very long and
powerful, and the end has the underside covered with bare skin, exactly
resembling that of the finger or palm of the hand and apparently equally
sensitive. One of the common kinds of monkeys that accompany street
organ-players has a prehensile tail, but not of the most perfect kind;
since in this species the tail is entirely clad with hair to the tip,
and seems to be used chiefly to steady the animal when sitting on a
branch by being twisted round another branch near it. The statement is
often erroneously made that all American monkeys have prehensile tails;
but the fact is that rather less than half the known kinds have them
so, the remainder having this organ either short and bushy, or long
and slender, but entirely without any power of grasping. All
prehensile-tailed monkeys are American, but all American monkeys are not
prehensile-tailed.

By remembering these characters it is easy, with a little observation,
to tell whether any strange monkey comes from America or from the Old
World. If it has bare seat-pads, or if when eating it fills its mouth
till its cheeks swell out like little bags, we may be sure it comes from
some part of Africa or Asia; while if it can curl up the end of its tail
so as to take hold of anything, it is certainly American. As all the
tailed monkeys of the Old World have seat-pads (or ischial callosities
as they are called in scientific language), and as all the American
monkeys have tails, but no seat-pads, this is the most constant external
character by which to distinguish them; and having done so we can look
for the other peculiarities of the American monkeys, especially the
distance apart of the nostrils and their lateral position.

The whole monkey-tribe is especially tropical, only a few kinds being
found in the warmer parts of the temperate zone. One inhabits the Rock
of Gibraltar, and there is one very like it in Japan, and these are the
two monkeys which live furthest from the equator. In the tropics they
become very abundant and increase in numbers and variety as we approach
the equator, where the climate is hot, moist, and equable, and where
flowers, fruits, and insects are to be found throughout the year. Africa
has about 55 different kinds, Asia and its islands about 60, while
America has 114, or almost exactly the same as Asia and Africa together.
Australia and its islands have no monkeys, nor has the great and
luxuriant island of New Guinea, whose magnificent forests seem so well
adapted for them. We will now give a short account of the different
kinds of monkeys inhabiting each of the tropical continents.

Africa possesses two of the great man-like apes--the gorilla and the
chimpanzee, the former being the largest ape known, and the one which,
on the whole, perhaps most resembles man, though its countenance is less
human than that of the chimpanzee. Both are found in West Africa, near
the equator, but they also inhabit the interior wherever there are great
forests; and Dr. Schweinfurth states that the chimpanzee inhabits the
country about the sources of the Shari River in 28° E. long. and 4° N.
lat.

The long-tailed monkeys of Africa are very numerous and varied. One
group has no cheek pouches and no thumb on the hand, and many of these
have long soft fur of varied colors. The most numerous group are the
Guenons, rather small long-tailed monkeys, very active and lively,
and often having their faces curiously marked with white or black, or
ornamented with whiskers or other tufts of hair; and they all have large
cheek pouches and good sized thumbs. Many of them are called green
monkeys, from the greenish yellow tint of their fur, and most of them
are well formed, pleasing animals. They are found only in tropical
Africa.

The baboons are larger but less numerous. They resemble dogs in the
general form and the length of the face or snout, but they have hands
with well-developed thumbs on both the fore and hind limbs; and this,
with something in the expression of the face and their habit of sitting
up and using their hands in a very human fashion, at once shows that
they belong to the monkey tribe. Many of them are very ugly, and in
their wild state they are the fiercest and most dangerous of monkeys.
Some have the tail very long, others of medium length, while it is
sometimes reduced to a mere stump, and all have large cheek pouches and
bare seat pads. They are found all over Africa, from Egypt to the Cape
of Good Hope; while one species, called the hamadryas, extends from
Abyssinia across the Red Sea into Arabia, and is the only baboon found
out of Africa. This species was known to the ancients, and it is often
represented in Egyptian sculptures, while mummies of it have been found
in the catacombs. The largest and most remarkable of all the baboons
is the mandrill of West Africa, whose swollen and hog-like face is
ornamented with stripes of vivid blue and scarlet. This animal has a
tail scarcely two inches long, while in size and strength it is not much
inferior to the gorilla. The large baboons go in bands, and are said to
be a match for any other animals in the African forests, and even to
attack and drive away the elephants from the districts they inhabit.

Turning now to Asia, we have first one of the best known of the large
man-like apes--the orang-outang, found only in the two large islands,
Borneo and Sumatra. The name is Malay, signifying "man of the woods,"
and it should be pronounced órang-óotan, the accent being on the first
syllable of both words. It is a very curious circumstance that, whereas
the gorilla and chimpanzee are both black, like the negroes of the same
country, the orang-outang is red or reddish brown, closely resembling
the color of the Malays and Dyaks who live in the Bornean forests.
Though very large and powerful, it is a harmless creature, feeding on
fruit, and never attacking any other animal except in self-defense. A
full-grown male orang-outang is rather more than four feet high, but
with a body as large as that of a stout man, and with enormously long
and powerful arms.

Another group of true apes inhabit Asia and the larger Asiatic islands,
and are in some respects the most remarkable of the whole family. These
are the Gibbons, or long-armed apes, which are generally of small size
and of a gentle disposition, but possessing the most wonderful agility.
In these creatures the arms are as long as the body and legs together,
and are so powerful that a gibbon will hang for hours suspended from
a branch, or swing to and fro and then throw itself a great distance
through the air. The arms, in fact, completely take the place of the
legs for traveling. Instead of jumping from bough to bough and running
on the branches, like other apes and monkeys, the gibbons move along
while hanging suspended in the air, stretching their arms from bough to
bough, and thus going hand over hand as a very active sailor will climb
along a rope. The strength of their arms is, however, so prodigious,
and their hold so sure, that they often loose one hand before they have
caught a bough with the other, thus seeming almost to fly through the
air by a series of swinging leaps; and they travel among the network of
interlacing boughs a hundred feet above the earth with as much ease and
certainty as we walk or run upon level ground, and with even greater
speed. These little animals scarcely ever come down to the ground of
their own accord; but when obliged to do so they run along almost erect,
with their long arms swinging round and round, as if trying to find some
tree or other object to climb upon. They are the only apes who naturally
walk without using their hands as well as their feet; but this does not
make them more like men, for it is evident that the attitude is not an
easy one, and is only adopted because the arms are habitually used to
swing by, and are therefore naturally held upward, instead of downward,
as they must be when walking on them.

The tailed monkeys of Asia consist of two groups, the first of which
have no cheek pouches, but always have very long tails, They are
true forest monkeys, very active and of a shy disposition. The most
remarkable of these is the long-nosed monkey of Borneo, which is very
large, of a pale brown color, and distinguished by possessing a long,
pointed, fleshy nose, totally unlike that of all other monkeys. Another
interesting species is the black and white entellus monkey of India,
called the "Hanuman," by the Hindoos, and considered sacred by them.
These animals are petted and fed, and at some of the temples numbers
of them come every day for the food which the priests, as well as the
people, provide for them.

The next group of Eastern monkeys are the Macaques, which are more like
baboons, and often run upon the ground. They are more bold and vicious
than the others. All have cheek pouches, and though some have long
tails, in others the tail is short, or reduced to a mere stump. In some
few this stump is so very short that there appears to be no tail, as in
the magot of North Africa and Gibraltar, and in an allied species that
inhabits Japan.


AMERICAN MONKEYS.

The monkeys which inhabit America form three very distinct groups:
1st, the Sapajous, which have prehensile or grasping tails; 2nd, the
Sagouins, which have ordinary tails, either long or short; and, 3rd, the
Marmosets, very small creatures, with sharp claws, long tails which are
not prehensile, and a smaller number of teeth than all other American
monkeys. Each of these three groups contain several sub-groups, or
_genera_, which often differ remarkably from each other, and from all
the monkeys of the Old World.

We will begin with the howling monkeys, which are the largest found in
America, and are celebrated for the loud voice of the males. Often in
the great forests of the Amazon or Oronooko a tremendous noise is heard
in the night or early morning, as if a great assemblage of wild beasts
were all roaring and screaming together. The noise may be heard for
miles, and it is louder and more piercing than that of any other
animals, yet it is all produced by a single male howler, sitting on the
branches of some lofty tree. They are enabled to make this extraordinary
noise by means of an organ that is possessed by no other animal. The
lower jaw is unusually deep, and this makes room for a hollow bony
vessel about the size of a large walnut, situated under the root of the
tongue, and having an opening into the windpipe by which the animal
can force air into it. This increases the power of its voice, acting
something like the hollow case of a violin, and producing those
marvelous rolling and reverberating sounds which caused the celebrated
traveler Waterton to declare that they were such as might have had their
origin in the infernal regions. The howlers are large and stout bodied
monkeys, with bearded faces, and very strong and powerfully grasping
tails. They inhabit the wildest forests; they are very shy, and are
seldom taken captive, though they are less active than many other
American monkeys.

Next come the spider monkeys, so called from their slender bodies and
enormously long limbs and tail. In these monkeys the tail is so long,
strong, and perfect, that it completely takes the place of a fifth hand.
By twisting the end of it round a branch the animal can swing freely in
the air with complete safety; and this gives them a wonderful power of
climbing end passing from tree to tree, because the distance they can
stretch is that of the tail, body, and arm added together, and these are
all unusually long. They can also swing themselves through the air for
great distances, and are thus able to pass rapidly from tree to tree
without ever descending to the ground, just like the gibbons in the
Malayan forests. Although capable of feats of wonderful agility, the
spider monkeys are usually slow and deliberate in their motions, and
have a timid, melancholy expression, very different from that of most
monkeys. Their hands are very long, but have only four fingers, being
adapted for hanging on to branches rather than for getting hold of small
objects. It is said that when they have to cross a river the trees on
the opposite banks of which do not approach near enough for a leap,
several of them form a chain, one hanging by its tail from a lofty
overhanging branch and seizing hold of the tail of the one below it,
then gradually swinging themselves backward and forward till the lower
one is able to seize hold of a branch on the opposite side. He then
climbs up the tree, and, when sufficiently high, the first one lets go,
and the swing either carries him across to a bough on the opposite side
or he climbs up over his companions.

Closely allied to the last are the woolly monkeys, which have an equally
well developed prehensile tail, but better proportioned limbs, and a
thick woolly fur of a uniform gray or brownish color. They have well
formed fingers and thumbs, both on the hands and feet, and are rather
deliberate in their motions, and exceedingly tame and affectionate in
captivity. They are great eaters, and are usually very fat. They are
found only in the far interior of the Amazon valley, and, having a
delicate constitution, seldom live long in Europe. These monkeys are not
so fond of swinging themselves about by their tails as are the spider
monkeys, and offer more opportunities of observing how completely this
organ takes the place of a fifth hand. When walking about a house, or on
the deck of a ship, the partially curled tail is carried in a horizontal
position on the ground, and the moment it touches anything it twists
round it and brings it forward, when, if eatable, it is at once
appropriated; and when fastened up the animal will obtain any food that
may be out of reach of its hands with the greatest facility, picking up
small bits of biscuit, nuts, etc., much as an elephant does with the tip
of his trunk.

We now come to a group of monkeys whose prehensile tail is of a less
perfect character, since it is covered with hair to the tip, and is of
no use to pick up objects. It can, however, curl round a branch, and
serves to steady the animal while sitting or feeding, but is never used
to hang and swing by in the manner so common with the spider monkeys and
their allies. These are rather small-sized animals, with round heads and
with moderately long tails. They are very active and intelligent, their
limbs are not so long as in the preceding group, and though they have
five fingers on each hand and foot, the hands have weak and hardly
opposable thumbs. Some species of these monkeys are often carried about
by itinerant organ men, and are taught to walk erect and perform many
amusing tricks. They form the genus _Cebus_ of naturalists.

The remainder of the American monkeys have non-prehensile tails, like
those of the monkeys of the Eastern hemisphere; but they consist of
several distinct groups, and differ very much in appearance and habits.
First we have the Sakis, which have a bushy tail and usually very long
and thick hair, something like that of a bear. Sometimes the tail is
very short, appearing like a rounded tuft of hair; many of the species
have fine bushy whiskers, which meet under the chin, and appear as if
they had been dressed and trimmed by a barber, and the head is often
covered with thick curly hair, looking like a wig. Others, again, have
the face quite red, and one has the head nearly bald, a most remarkable
peculiarity among monkeys. This latter species was met with by Mr. Bates
on the Upper Amazon, and he describes the face as being of a vivid
scarlet, the body clothed from neck to tail with very long, straight,
and shining white hair, while the head was nearly bald, owing to the
very short crop of thin gray hairs. As a finish to their striking
physiognomy these monkeys have bushy whiskers of a sandy color meeting
under the chin, and yellowish gray eyes. The color of the face is so
vivid that it looks as if covered with a thick coat of bright scarlet
paint. These creatures are very delicate, and have never reached Europe
alive, although several of the allied forms have lived some time in our
Zoological Gardens.

An allied group consists of the elegant squirrel monkeys, with long,
straight, hairy tails, and often adorned with pretty variegated colors.
They are usually small animals; some have the face marked with black and
white, others have curious whiskers, and their nails are rather sharp
and claw like. They have large round heads, and their fur is more glossy
and smooth than in most other American monkeys, so that they more
resemble some of the smaller monkeys of Africa. These little creatures
are very active, running about the trees like squirrels, and feeding
largely on insects as well as on fruit.

Closely allied to these are the small group of night monkeys, which have
large eyes, and a round face surrounded by a kind of ruff of whitish
fur, so as to give it an owl like appearance, whence they are sometimes
called owl-faced monkeys. They are covered with soft gray fur, like that
of a rabbit, and sleep all day long concealed in hollow trees. The
face is also marked with white patches and stripes, giving it a rather
carnivorous or cat like aspect, which, perhaps, serves as a protection,
by causing the defenseless creature to be taken for an arboreal tiger
cat or some such beast of prey.

This finishes the series of such of the American monkeys as have a
larger number of teeth than those of the Old World. But there is another
group, the Marmosets, which have the same number of teeth as Eastern
monkeys, but differently distributed in the jaws, a premolar being
substituted for a molar tooth. In other particulars they resemble the
rest of the American monkeys. They are very small and delicate creatures
some having the body only seven inches long. The thumb of the hands
is[1] not opposable, and instead of nails they have sharp compressed
claws. These diminutive monkeys have long, non-prehensile tails, and
they have a silky fur often of varied and beautiful colors. Some are
striped with gray and white, or are of rich brown or golden brown tints,
varied by having the head or shoulders white or black, while in many
there are crests, frills, manes, or long ear tufts, adding greatly to
their variety and beauty. These little animals are timid and restless;
their motions are more like those of a squirrel than a monkey. Their
sharp claws enable them to run quickly along the branches, but they
seldom leap from bough to bough like the larger monkeys. They live on
fruits and insects, but are much afraid of wasps, which they are said to
recognize even in a picture.

[Transcribers note 1: Changed from '... it not opposable', ...]

This completes our sketch of the American monkeys, and we see that,
although they possess no such remarkable forms as the gorilla or the
baboons, yet they exhibit a wonderful diversity of external characters,
considering that all seem equally adapted to a purely arboreal life.
In the howlers we have a specially developed voice organ, which is
altogether peculiar; in the spider monkeys we find the adaptation to
active motion among the topmost branches of the forest trees carried to
an extreme point of development; while the singular nocturnal monkeys,
the active squirrel monkeys, and the exquisite little marmosets, show
how distinct are the forms under which the same general type, may be
exhibited, and in how many varied ways existence may be sustained under
almost identical conditions.


LEMURS.

In the general term, monkeys, considered as equivalent to the order
Primates, or the Quadrumana of naturalists, we have to include another
sub-type, that of the Lemurs. These animals are of a lower grade than
the true monkeys, from which they differ in so many points of structure
that they are considered to form a distinct sub-order, or, by some
naturalists, even a separate order. They have usually a much larger head
and more pointed muzzle than monkeys; they vary considerably in the
number, form, and arrangement of the teeth; their thumbs are always well
developed, but their fingers vary much in size and length; their tails
are usually long, but several species have no tail whatever, and they
are clothed with a more or less woolly fur, often prettily variegated
with white and black. They inhabit the deep forests of Africa,
Madagascar, and Southern Asia, and are more sluggish in their movements
than true monkeys, most of them being of nocturnal and crepuscular
habits. They feed largely on insects, eating also fruits and the eggs or
young of birds.

The most curious species are--the slow lemurs of South India, small
tailless nocturnal animals, somewhat resembling sloths in appearance,
and almost as deliberate in their movements, except when in the act of
seizing their insect prey; the Tarsier, or specter lemur, of the Malay
islands, a small, long tailed nocturnal lemur, remarkable for the
curious development of the hind feet, which have two of the toes very
short, and with sharp claws, while the others have nails, the third toe
being exceedingly long and slender, though the thumb is very large,
giving the feet a very irregular and _outré_ appearance; and, lastly,
the Aye-aye, of Madagascar, the most remarkable of all. This animal has
very large ears and a squirrel like tail, with long spreading hair.
It has large curved incisor teeth, which add to its squirrel like
appearance, and caused the early naturalists to class it among the
rodents. But its most remarkable character is found in its fore feet
or hands, the fingers of which are all very long and armed with sharp
curved claws, but one of them, the second, is wonderfully slender,
being not half the thickness of the others. This curious combination of
characters shows that the aye-aye is a very specialized form--that is,
one whose organization has been slowly modified to fit it for a peculiar
mode of life. From information received from its native country, and
from a profound study of its organization, Professor Owen believes
that it is adapted for the one purpose of feeding on small wood-boring
insects. Its large feet and sharp claws enable it to cling firmly to the
branches of trees in almost any position; by means of its large delicate
ears it listens for the sound of the insect gnawing within the branch,
and is thus able to fix its exact position; with its powerful curved
gnawing teeth it rapidly cuts away the bark and wood till it exposes the
burrow of the insect, most probably the soft larva of some beetle, and
then comes into play the extraordinary long wire-like finger, which
enters the small cylindrical burrow, and with the sharp bent claw hooks
out the grub. Here we have a most complex adaptation of different parts
and organs, all converging to one special end, that end being the same
as is reached by a group of birds, the woodpeckers, in a different way;
and it is a most interesting fact that, although woodpeckers abound in
all the great continents, and are especially common in the tropical
forests of Asia, Africa, and America, they are quite absent from
Madagascar. We may, therefore, consider that the aye-aye really occupies
the same place in nature in the forests of this tropical island, as do
the woodpeckers in other parts of the world.


DISTRIBUTION, AFFINITIES, AND ZOOLOGICAL RANK OF MONKEYS.

Having thus sketched an outline of the monkey tribe as regards their
more prominent external characters and habits, we must say a few words
on their general relations as a distinct order of mammalia. No other
group so extensive and so varied as this, is so exclusively tropical in
its distribution, a circumstance no doubt due to the fact that monkeys
depend so largely on fruit and insects for their subsistence. A very
few species extend into the warmer parts of the temperate zones, their
extreme limits in the northern hemisphere being Gibraltar, the Western
Himalayas at 11,000 feet elevation, East Thibet, and Japan. In America
they are found in Mexico, but do not appear to pass beyond the tropic.
In the Southern hemisphere they are limited by the extent of the forests
in South Brazil, which reach about 30° south latitude. In the East,
owing to their entire absence from Australia, they do not reach the
tropic; but in Africa, some baboons range to the southern extremity of
the continent.

But this extreme restriction of the order to almost tropical lands is
only recent. Directly we go back to the Pliocene period of geology,
we find the remains of monkeys in France, and even in England. In the
earlier Miocene, several kinds, some of large size, lived in France,
Germany, and Greece, all more or less closely allied to living forms of
Asia and Africa. About the same period monkeys of the South American
type inhabited the United States. In the remote Eocene period the same
temperate lands were inhabited by lemurs in the East, and by curious
animals believed to be intermediate between lemurs and marmosets in the
West. We know from a variety of other evidence that throughout these
vast periods a mild and almost sub-tropical climate extended over all
Central Europe and parts of North America, while one of a temperate
character prevailed as far north as the Arctic circle. The monkey tribe
then enjoyed a far greater range over the earth, and perhaps filled a
more important place in nature than it does now. Its restriction to the
comparatively narrow limits of the tropics is no doubt mainly due to the
great alteration of climate which occurred at the close of the Tertiary
period, but it may have been aided by the continuous development of
varied forms of mammalian life better fitted for the contrasted seasons
and deciduous vegetation of the north temperate regions. The more
extensive area formerly inhabited by the monkey tribe, would have
favored their development into a number of divergent forms, in distant
regions, and adapted to distinct modes of life. As these retreated
southward and became concentrated in a more limited area, such as were
able to maintain themselves became mingled together as we now find them,
the ancient and lowly marmosets and lemurs subsisting side by side with
the more recent and more highly developed howlers and anthropoid apes.

Throughout the long ages of the Tertiary period monkeys must have been
very abundant and very varied, yet it is but rarely that their fossil
remains are found. This, however, is not difficult to explain. The
deposits in which mammalian remains most abound are those formed in
lakes or in caverns. In the former the bodies of large numbers of
terrestrial animals were annually deposited, owing to their having been
caught by floods in the tributary streams, swallowed up in marginal bogs
or quicksands, or drowned by the giving way of ice. Caverns were the
haunts of hyenas, tigers, bears, and other beasts of prey, which dragged
into them the bodies of their victims, and left many of their bones to
become embedded in stalagmite or in the muddy deposit left by floods,
while herbivorous animals were often carried into them by these floods,
or by falling down the swallow-holes which often open into caverns from
above. But, owing to their arboreal habits, monkeys were to a great
extent freed from all these dangers. Whether devoured by beasts or birds
of prey, or dying a natural death, their bones would usually be left on
dry land, where they would slowly decay under atmospheric influences.
Only under very exceptional circumstances would they become embedded
in aqueous deposits; and instead of being surprised at their rarity
we should rather wonder that so many have been discovered in a fossil
state.

Monkeys, as a whole, form a very isolated group, having no near
relations to any other mammalia. This is undoubtedly an indication of
great antiquity. The peculiar type which has since reached so high a
development must have branched off the great mammalian stock at a very
remote epoch, certainly far back in the Secondary period, since in the
Eocene we find lemurs and lemurine monkeys already specialized. At this
remoter period they were probably not separable from the insectivora,
or (perhaps) from the ancestral marsupials. Even now we have one living
form, the curious Galeopithecus or flying lemur, which has only recently
been separated from the lemurs, with which it was formerly united, to be
classed as one of the insectivora; and it is only among the Opossums and
some other marsupials that we again find hand-like feet with opposable
thumbs, which are such a curious and constant feature of the monkey
tribe.

This relationship to the lowest of the mammalian tribes seems
inconsistent with the place usually accorded to these animals at the
head of the entire mammalian series, and opens up the question whether
this is a real superiority or whether it depends merely on the obvious
relationship to ourselves. If we could suppose a being gifted with
high intelligence, but with a form totally unlike that of man, to have
visited the earth before man existed in order to study the various forms
of animal life that were found there, we can hardly think he would have
placed the monkey tribe so high as we do. He would observe that their
whole organization was specially adapted to an arboreal life, and this
specialization would be rather against their claiming the first rank
among terrestrial creatures. Neither in size, nor strength, nor beauty,
would they compare with many other forms, while in intelligence they
would not surpass, even if they equaled, the horse or the beaver. The
carnivora, as a whole, would certainly be held to surpass them in the
exquisite perfection of their physical structure, while the flexible
trunk of the elephant, combined with his vast strength and admirable
sagacity, would probably gain for him the first rank in the animal
creation.

But if this would have been a true estimate, the mere fact that the ape
is our nearest relation does not necessarily oblige us to come to any
other conclusion. Man is undoubtedly the most perfect of all animals,
but he is so solely in respect of characters in which he differs from
all the monkey tribe--the easily erect posture, the perfect freedom
of the hands from all part in locomotion, the large size and complete
opposability of the thumb, and the well developed brain, which enables
him fully to utilize these combined physical advantages. The monkeys
have none of these; and without them the amount of resemblance they have
to us is no advantage, and confers no rank. We are biased by the too
exclusive consideration of the man-like apes. If these did not exist
the remaining monkeys could not be thereby deteriorated as to their
organization or lowered in their zoological position, but it is doubtful
if we should then class them so high as we now do. We might then dwell
more on their resemblances to lower types--to rodents, to insectivora,
and to marsupials, and should hardly rank the hideous baboon above the
graceful leopard or stately stag. The true conclusion appears to be,
that the combination of external characters and internal structure which
exists in the monkeys, is that which, when greatly improved, refined,
and beautified, was best calculated to become the perfect instrument
of the human intellect and to aid in the development of man's higher
nature; while, on the other hand, in the rude, inharmonious, and
undeveloped state which it has reached in the quadrumana, it is by no
means worthy of the highest place, or can be held to exhibit the most
perfect development of existing animal life.--_Contemporary Review_.

       *       *       *       *       *

[JOURNAL OF THE SOCIETY OF ARTS.]




SILK-PRODUCING BOMBYCES AND OTHER LEPIDOPTERA REARED IN 1881.

By ALFRED WAILLY, Membre Lauréat de la Société d'Acclimatation de
France.


By referring to my reports for the years 1879 and 1880, which appeared
in the _Journal of the Society of Arts_, February 13 and March 5, 1880,
February 25 and March 4, 1881, it will be seen that the bad weather
prevented the successful rearing in the open air of most species of
silk-producing larvæ. In 1881, the weather was extremely favorable up
to the end of July, but the incessant and heavy rains of the month of
August and beginning of September, proved fatal to most of the larvæ
when they were in their last stages. However, in spite of my many
difficulties, I had the satisfaction of seeing them to their last
stage. Larvæ of all the silk-producing bombyces were preserved in their
different stages, and can be seen in the Bethnal-green Museum. In July,
when the weather was magnificent, the little trees in my garden were
literally covered with larvæ of more species than I ever had before, and
two or three more weeks of fair weather would have given me a good crop
of cocoons, instead of which I only obtained a very small number. The
sparrows, as usual, also destroyed a quantity of worms, in spite of wire
or fish-netting placed over some of the trees.

On the trees were to be seen--_Attacus cynthia_ (the Ailantus silkworm),
the rearing of which was, as usual, most successful; _Samia cecropia_
and _Samia gloveri_, from America; also hybrids of _Gloveri cecropia_
and _Cecropia gloveri_; _Samia promethea_ and _Telea polyphemus_;
_Attacus pernyi_, and a new hybrid, which I obtained this last season by
the crossing of Pernyi with Royle. For the first time I reared _Actias
selene_, from India, on a nut-tree in the garden, and _Attacus atlas_,
on the ailantus. The _Selene_ larvæ reached their fifth and last stage.
The Atlas larvæ only reached the third stage, and were destroyed by the
heavy rains; only two remained on the tree till about the 8th or 9th of
September, when they had to be removed. I shall now reproduce the notes
I took on some of the various species I reared.

_Actias Selene_.--With sixty cocoons I only obtained one pairing. The
moths emerged from the beginning of March till the 13th of August,
at intervals of some duration, or in batches of males or females. I
obtained a pairing of Selene on the 30toh of June, 1881, and the worms
commenced to hatch on the 13th of July. The larvæ in first stage are of
a fine brown-red, with a broad black band in the middle of the body. The
second stage commenced on the 20th of July; larvæ, of a lighter reddish
color, without the black band; tubercles black. Third stage commenced on
the 28th of July; larvæ green; the first four tubercles yellow, with a
black ring at the base; other tubercles, orange yellow. Fourth stage
commenced on the 6th of August; larvæ green; first four tubercles
golden-yellow, the others orange-red. Fifth stage commenced on the 19th
of August; first four tubercles yellow, with a black ring at the base;
other tubercles yellow, slightly tinged with orange-red; lateral band
brown and greenish yellow; head and forelegs dark-brown. As stated
before, the larvæ were reared on a nut-tree in the garden, till the last
stage. Selene feeds on various trees--walnut, wild cherry, wild pear,
etc. In Ceylon (at Kandy), it is found on the wild olive tree. As far as
I am informed by correspondents in Ceylon, this species is not found--or
is seldom found--on the coasts, but _Attacus atlas_ and Mylitta are
commonly found there.

_Attacus (antheroea) roylei_ (with sixty cocoons); three pairings only
were obtained, and this species I found the most difficult to pair in
captivity. Two moths emerged on the 5th of March, a male and a female,
and a pairing was obtained; but the weather being then too cold, the ova
were not fertile, the female moth, after laying about two hundred eggs,
lived till the 22d of March, which is a very long time; this was owing
to the low temperature. The moths emerged afterward from the 8th of
April till the 25th of June. A pairing took place on the 2d of June, and
another on the 6th of June.

Roylei (the Himalaya oak silkworm) is very closely allied to Pernyi, the
Chinese oak silkworm; the Roylei moths are of a lighter color, but the
larvæ of both species can hardly be distinguished from one another.
The principal difference between the two species is in the cocoon. The
Roylei cocoon is within a very large and tough envelope, while that of
Pernyi has no outer envelope at all. The larvæ of Roylei I reared did
not thrive, and the small number I had only went to the fourth stage,
owing to several causes. I bred them under glass, in a green-house. A
certain number of the larvæ were unable to cut the shell of the egg.

Here are a few notes I find in my book: Ova of Roylei commenced to hatch
on the 29th of June; second stage commenced on the 9th of July. The
larvæ in the first two stages seemed to me similar to those of Pernyi,
as far as I could see. In second stage, the tubercles were of a
brilliant orange-red; on anal segment, blue dot on each side. Third
stage, four rows of orange-yellow tubercles, two blue dots on anal
segment, brilliant gold metallic spots at the base of the tubercles on
the back, and silver metallic spots at the base of the tubercles on the
sides. No further notes taken.

One of my correspondents in Vienna (Austria) obtained a remarkable
success in the rearing of Roylei. From the twenty-five eggs he had
twenty-three larvæ hatched, which produced twenty-three fine cocoons.
The same correspondent, with thirty-five eggs of _Samia gloveri_,
obtained twenty cocoons. My other correspondents did not obtain any
success in rearing these two species, as far as I know.

_Hybrid Roylei-Pernyi_.--I have said that it is extremely difficult to
obtain the pairing of Roylei moths in captivity. But the male Pernyi
paired readily with the female Roylei. I obtained six such pairings, and
a large quantity of fertile ova. The pairings of Roylei (female) with
Pernyi (male) took place as follows: two on the 21st of May, one on the
3d of June, two on the 4th of June, and one on the 6th.

The larvæ of this new hybrid, _Roylei-Pernyi_, contrary to what might
have been expected, were much easier to rear than those of Roylei, and
the cocoons obtained are far superior to those of Roylei, in size,
weight, and richness of silk. The cocoon of my new hybrid has, like
Roylei, an envelope, but there is no space between this envelope and the
true cocoon inside. Therefore, this time, the crossing of two different
species (but, it must be added, two very closely allied species) has
produced a hybrid very superior, at least to one of the types, that of
Roylei. The cocoons of the hybrid _Roylei-Pernyi_ seem to me larger and
heavier than any Pernyi cocoons I have as yet seen.

The larvæ of this new hybrid have been successfully reared in France,
in Germany, in Austria, and in the United States of North America. The
cocoons obtained by Herr L. Huessman, one of my German correspondents,
are remarkable for their size and beauty. The silk is silvery white.

I have seventeen cocoons of this hybrid species, which number may be
sufficient for its reproduction. But the question arises, "Will the
moths obtained from these cocoons be susceptible of reproduction?"

In my report on Lepidoptera for the year 1879, I stated, with respect to
hybrids and degeneracy, that hybrids had been obtained by the crossing
of _Attacus pernyi_ and _Attacus yama-maï_, but that, although the moths
(some of which may be seen in the Bethnal-green Museum) are large and
apparently perfect in every respect, yet these hybrids could not be
reproduced. It must be stated that these two species differ essentially
in one particular point. _Yama-maï_ hibernates in the _ovum_ state,
while Pernyi hibernates in the _pupa_ state. The hybrids hibernated in
the _pupa_ state. Roylei, as Pernyi, hibernates in the _pupa_ state.

In the November number, 1881, of "The Entomologist," Mr. W.F. Kirby,
of the British Museum, wrote an article having for its title,
"Hermaphrodite-hybrid Sphingidæ," in which, referring to hybrids of
_Smerinthus ocellatus_ and _populi_, he says that hermaphroditism is the
usual character of such hybrids.

I extract the following passage from his article: "I was under the
impression that hermaphroditism was the usual character of these
hybrids; and it has suggested itself to my mind as a possibility, which
I have not, at present, sufficient data either to prove or to disprove,
that the sterility of hybrids in general (still a somewhat obscure
subject) may perhaps be partly due to hybridism having a tendency to
produce hermaphroditism."

Now, will the moths of new hybrid Roylei pernyi (which I expect will
emerge in May or June, 1882) have the same tendency to hermaphroditism
as has been observed with the hybrids obtained by the crossing of
_Smerinthus populi_ with _Sm. ocellatus_? I do not think that such will
be the case with the moths of the hybrid Roylei-pernyi, on account of
the close relationship of Roylei with Pernyi, but nothing certain can be
known till the moths have emerged. Here are the few notes taken on the
hybrid Roylei-pernyi: Ova commenced to hatch on the 12th of June; these
were from the pairing which had taken place on the 21st of May. Larvæ,
black, with long white hairs. Second stage commenced on the 21st of
June. Larva, of a beautiful green; tubercles orange-yellow; head dark
brown. Third stage commenced on the 1st of July; fourth stage on the
7th. Larva of same color in those stages; tubercles on the back,
violet-blue or mauve; tubercles on the sides, blue. Fifth stage
commenced on the 18th of July. Larva, with tubercles on back and sides,
blue, or violet-blue. First cocoon commenced on the 10th of August. Want
of time prevented me from taking fuller and more accurate notes.

_Attacus Atlas_.--For the first time, as stated before, I attempted the
rearing of a small number of Atlas larvæ in the open air on the ailantus
tree, but had to remove the last two remaining larvæ in September; the
others had all disappeared in consequence of the heavy and incessant
rains. These larvæ were from eggs sent to me by one of my German
correspondents. The pairing of the moths had taken place on the 17th of
July, and the eggs had commenced to hatch on the 4th of August.

I had about eighty cocoons of another and larger race of Atlas imported
from the Province of Kumaon, but only eight moths emerged at intervals
from the 31st of July to the 30th of September. Not only did the moths
emerge too late in the season, but there never was a chance of obtaining
a pairing. In my report on Indian silkworms, published in the November
number of the "Bulletin de la Societe d'Acclimatation," for the year
1881, compiled from the work of Mr. J. Geoghegan, I reproduce the first
appendix of Captain Thomas Hutton to Mr. Geoghegan's work, in which are
given the names of all the Indian silkworms known by him up to the year
1871.

Of _Attacus atlas_, Captain Hutton says: "It is common at 5,500 feet at
Mussoorie, and in the Dehra Doon; it is also found in some of the deep
warm glens of the outer hills. It is also common at Almorah, where the
larva feeds almost exclusively upon the 'Kilmorah' bush or _Berberis
asiatica_; while at Mussoorie it will not touch that plant, but feeds
exclusively upon the large milky leaves of _Falconeria insignis_.
The worm is, perhaps, more easily reared than any other of the wild
bombycidæ."

I will now quote from letters received from one of my correspondents in
Ceylon, a gentleman of great experience and knowledge in sericulture.

In a letter dated 24th August, 1881, my correspondent says: "The Atlas
moth seems to be a near relation of the Cynthia, and would probably feed
on the Ailantus. Here it feeds on the cinnamon and a great number of
other trees of widely different species; but the tree on which I
have kept it most successfully in a domestic state is the _Milnea
roxburghiana_, a handsome tree, with dark-green ternate leaves, which
keep fresh long after being detached from the tree. I do not think the
cocoon can ever be reeled, as the thread usually breaks when it comes
to the open end. I have tried to reel a great many Atlas cocoons, but
always found the process too tedious and troublesome for practical use.

"The Mylitta (Tusser) is a more hardy species than the Atlas, and I have
had no difficulty in domesticating it. Here it feeds on the cashew-nut
tree, on the so-called almond of this country (_Terminalia catappa_),
which is a large tree entirely different from the European almond, and
on many other trees. Most of the trees whose leaves turn red when about
to fall seem to suit it, but it is not confined to these. In the case of
the Atlas moth, I discovered one thing which may be well worth knowing,
and that was, that with cocoons brought to the seaside after the larvæ
had been reared in the Central Provinces, in a temperature ten or twelve
degrees colder, the moths emerged in from ten to twenty days after the
formation of the cocoon. The duration of the _pupa_ stage in this, and
probably in other species, therefore, depends upon the temperature in
which the larvæ have lived, as well as the degree of heat in which the
cocoons are kept; and in transporting cocoons from India to Europe, I
think it will be found that the moths are less liable to be prematurely
forced out by the heat of the Red Sea when the larvæ have been reared in
a warm climate than when they have been reared in a cold one.

"I do not agree with the opinion expressed in one of your reports, that
the short duration of the larva stage, caused by a high temperature, has
the effect of diminishing the size of the cocoons, because the Atlas
and Tusser cocoons produced at the sea-level here are quite as large as
those found in the Central Provinces at elevations of three thousand
feet or more. According to the treatise on the "Silk Manufacture," in
"Lardner's Cyclopedia," the Chinese are of opinion that one drachm
of mulberry silkworms' eggs will produce 25 ounces of silk if the
caterpillars attain maturity within twenty-five days; 20 ounces if the
commencement of the cocoons be delayed until the twenty-eighth day; and
only 10 ounces if it be delayed until between the thirtieth and fortieth
day. If this is correct, a short-lived larva stage must, instead of
causing small cocoons, produce just the contrary effect."

In another letter, dated November 25, 1881, my correspondent says: "I am
sorry that you have not had better success in the rearing of your
larvæ, but you should not despair. It is possible that the choice of an
improper food-plant may have as much to do with failures as the coldness
and dampness of the English climate. I lost many thousands of Atlas
caterpillars before I found out the proper tree to keep them on in a
domesticated state; and when I did attain partial success, I could
not keep them for more than one generation, till I found the _Milnea
roxburghiana_ to be their proper food plant. I do not know the proper
food-plant of the Mylitta (Tusser), but I have succeeded very well with
it, as it is a more hardy species than the Atlas. Though a Bombyx be
polyphagous in a state of nature, yet I think most species have a tree
proper to themselves, on which they are more at home than on any
other plant. I should like, if you could find out from some your
correspondents in India, on what species of tree Mylitta cocoons are
found in the largest numbers, and what is about the greatest number
found on a single tree. The Mylitta is common enough here, but there
does not seem to be any kind of tree here on which the cocoons are to be
found in greater numbers than twos and threes; and there must be some
tree in India on which the cocoons are to be found in much greater
plenty, because they could not otherwise be collected in sufficient
quantity for manufacturing purposes. The Atlas is here found on twenty
or more different kinds of trees, but a hundred or a hundred and fifty
cocoons or larvæ may be found on a single tree of _Milnea roxburghiana_,
while they are to be found only singly, or in twos and threes, on any
other tree that I know of. The Atlas and Mylitta seem to be respectively
the Indian relations of the Cynthia and Pernyi. It is, therefore,
probable that the Ailantus would be the most suitable European tree for
the Atlas, and the oak for the Mylitta."

_Attacus mylitta_ (_Antheræa paphia_).--I did not receive a single
cocoon of this species for the season 1881. My stock consisted of seven
cocoons, from the lot received from Calcutta at the end of February,
1880. Five were female, and two male cocoons; one of the latter died,
thus reducing the number to six. The moths emerged as follows: One
female on the 21st of June, one female on the 26th, one female on the
28th, one female on the 1st of July, and one male on the 3d of August;
the latter emerging thirty-four days too late to be of any use for
rearing purposes. The last female moth emerged, I think, about the end
of September. These cocoons had hibernated twice, as has been the case
with other Indian species. I had Indian cocoons which hibernated even
three times.

_Attacus cynthia_, from the province of Kumaon.--With the Atlas cocoons,
a large quantity of Cynthia cocoons were collected in the province
of Kumaon. Both species had, no doubt, fed on the same trees; as the
Cynthia, like the Atlas cocoons, were all inclosed in leaves of the
_Berberis vulgaris_, which shows that Cynthia is also a polyphagous
species. It is already known that it feeds on several species of trees,
besides the ailantus, such as the laburnum, lilac, cherry, and, I think,
also on the castor-oil plant; the common barberry has, therefore, to be
added to the above food plants.

These Kumaon Cynthia cocoons were somewhat smaller and much darker in
color than those of the acclimatized Cynthia reared on the ailantus. The
moths of this wild Indian Cynthia were also of a richer color than those
of the cultivated species in Europe.

During the summer 1881, I saw cocoons of my own Cynthia race obtained
from worms which had been reared on the laburnum tree. These cocoons
were, as far as I can remember, of a yellowish or saffron color; which
I had never seen before. This difference in the color of the cocoon was
very likely produced by the change of food, although it has been stated,
and I think it may be quite correct, that with many species of native
lepidoptera the change of food-plants does not produce any difference of
color in the insects obtained. With respect to the Cynthia worms reared
on the laburnum instead of the ailantus, it may be that the moths, which
will emerge from the yellow cocoons, will be similar to those obtained
from cocoons spun by worms bred on the ailantus, and that the only
difference will be in the color of the cocoons.

The Kumaon Cynthia cocoons, as I found it to be the case with Indian
species introduced for the first time into Europe, did not produce moths
at the same time, nor as regularly as the acclimatized species. The
moths emerged as follows: One female on the 22d of July; one female on
the 25th; one male on the 3d August; one female on the 19th; one male on
the 28th of August; one male on the 2d September; one female on the 3d.
A pairing was obtained with the latter two. Two males emerged on the 4th
of September; one male on the 6th; one male and one female on the 22d;
one female on the 23d; and one female on the 25th of September. Five
cocoons, which did not produce any moths, contain pupæ, which are still
in perfect condition; and the moths will no doubt emerge next summer
(1882). As seen in my note, a pairing of this wild Indian Cynthia took
place; this was from the evening of the 4th to the 5th of September. The
eggs laid by the female moth were deposited in a most curious way, in
smaller or larger quantities, but all forming perfect triangles. These
eggs I gave to a florist who has been very successful in the rearing
of silk-producing and other larvæ; telling him to rear the Cynthia on
lilacs grown in pots and placed in a hot-house, which was done. The
worms, which hatched in a few days, as they were placed in a hot-house,
thrived wonderfully well, and I might say they thrived too well, as they
grew so fast and became so voracious that the growth of the lilac trees
could not keep pace with the growth of the worms. These, at the fourth
stage, became so large that the foliage was entirely devoured, and, of
course, the consequence was that all the worms were starved. I only
heard of the result of that experiment long after the death of the
larvæ; otherwise I should have suggested the use of another plant after
the destruction of the foliage of the lilacs; the privet (_Ligustrum
vulgare_) might have been tried, and success obtained with it.

Of such species as _Attacus pyri_, of Central Europe, and _Attacus
pernyi_, the North Chinese oak silkworm, which I have mentioned in my
previous reports, and bred every season for several years, I shall only
say that I never could rear Pyri in the open air in London, up to the
formation of the cocoon. As to Pernyi, I had, in 1881, an immense
quantity of splendid moths, from which I obtained the largest quantity
of ova I ever had of this species. I had many thousands of fertile ova
of Pernyi, which I was unable to distribute. Many schoolboys reared
Pernyi worms, but with what success I do not yet know. The number of
fertile ova obtained from Pyri moths was also more considerable than in
former years, which was due partly to the good quality of the pupæ, and
partly to the very favorable weather in June, at the time the pairings
of the moths took place.

Leaving these, I now come to the North American species.

_Telea polyphemus_.--As I have stated in former years, this is the best
North American silkworm, producing a closed cocoon, somewhat smaller
than that of Pernyi, but the silk seems as good as that of Pernyi.

The cocoons of Polyphemus I had in 1881 were smaller and inferior in
quality to those I had before. Those received in 1878 and 1879 were
considerably finer and larger than those which were sent in 1880 and
1881; besides, they were sent in much larger quantities. The cocoons
received this year (1882) are finer than those of 1881, but yet they
cannot be compared with those of 1878 and 1879.

With about sixty cocoons of _Telea polyphemus_ I only obtained three
pairings, which I attribute solely to the weakness of the moths, as
the weather was all that could be desired for the pairings. The moths
emerged from the 1st of June to the 20th of July. One male moth emerged
on the 7th September. This latter was one from a small number of cocoons
received from Alabama; the other cocoons of the same race had emerged at
the same time as the cocoons from the Northern States. In the Northern
States the species is single-brooded; in the Southern States it is
double-brooded.

The larvæ of Polyphemus can be bred in the open air in England, almost
as easily as those of Pernyi, and even Cynthia; they will pass through
their five stages and spin their cocoons on the trees, unless the
weather should be unexceptionally cold and wet, as was the case during
the month of August, 1881, when the larvæ had reached their full size;
they were reared this year on the nut-tree, and some on the oak. The
species is extremely polyphagous, and will feed well on oak, birch,
chestnut, beech, willow, nut, etc.

The moth of Polyphemus is very beautiful, and, as in some other species,
varies in its shades of color. The larva is of a transparent green, of
extreme beauty; the head is light brown; without any black dots, as in
Pernyi; the spines are pink, and at the base of each of them there is a
brilliant metallic spot. When the sun shines on them the larvæ seem to
be covered with diamonds. These metallic spots at the base of the spines
are also seen on Pernyi, Yama mai, Mylitta, and other species of the
genus Antheræa, all having a closed cocoon, but none of these have so
many as Polyphemus.

The cocoons of the species of the genus Actias are closed, but the larvæ
have not the metallic spots of the species of the genus Antheræa.

_Samia Gloveri_.--Three North American silk-producing bombyces, very
closely allied, have been mentioned in my previous reports; they are;
_Samia ceanothi_, from California; _Samia gloveri_, from Utah and
Arizona; and _Samia cecropia_, commonly found in most of the Northern
States--the latter is the best and largest silk producer. Crossings of
these species took places in 1880, and, as I stated before, the ova
obtained from a long pairing between a Ceanothi female with a Gloveri
male, were the only ones which were fertile. The Gloveri cocoons
received in 1880 were of a very inferior quality, and produced moths
from which no pairings could be obtained, although some crossings took
place. In 1881, the Gloveri cocoons, on the contrary, produced fine,
healthy moths; yet only five pairings could be obtained, with about one
hundred cocoons. Besides these five pairings, a quantity of fertile
ova were obtained by the crossings of _S. gloveri_ (female) with _S.
cecropia_ (male), and Cecropia (female) with Gloveri (male). No success,
so far as I know, was obtained with the rearing of the hybrid larvæ; the
rearings of the larvæ of pure Gloveri were also, I think, a failure,
only one correspondent having been successful; but some correspondents
have not yet made the result of their experiments known to me. The larvæ
of _Samia cecropia, S. gloveri_, and _S. ceanothi_, are very much alike;
and hardly any difference can be observed in the first two stages. In
the third and fourth stages, the larvæ of _S. cecropia_ and _S. gloveri_
are also nearly alike; the principal difference between these two
species and _S. cecropia_ being that the tubercles on the back are of a
uniform color--orange-red, or yellow--while on Cecropia the first four
dorsal tubercles are red, and the rest yellow. The tubercles on the
sides are blue on the three species.

The larvæ of the hybrids _Gloveri-cecropia_ were, as far as I could
observe, like those of Cecropia, but I noticed some with six red
tubercles on the back instead of four, as on Cecropia. They were reared
on plum, apple, and _Salix caprea_; in the open air.

The larvæ of _Samia gloveri_ were reared, during the first four stages
on a wild plum-tree, then on _Salix, caprea_, and I reproduce the notes
taken on this species, which I bred this year (1881) for the first time.

Gloveri moths emerged from the 15th of May to the end of June; five
pairings took place as follows: 1st, 4th, 9th, 24th, and 26th of June.
First stage--larvæ quite black. Second stage--larvæ orange, with black
spines. Third stage--dorsal spines, orange-red; spines on sides blue.
Fourth stage--dorsal spines, orange or yellow, spines on the sides blue;
body light blue on the back, and greenish yellow on the sides; head,
green; legs, yellow. Fifth and sixth stage--larvæ nearly the same;
tubercles on the back yellow, the first four having a black ring at the
base; side tubercles ivory-white, with a dark-blue base.

The above-mentioned American species, like most other silk-producing
bombyces, were bred in the open air; but besides these, I reared three
other species of American bombyces in the house, under glass, and with
the greatest success. These are: _Hyperchiria io_, a beautiful species
mentioned in my report for the year 1879; _Orgyia leucostigma_, from ova
received on December 29, 1880, from Madison, Wis., which hatched on the
27th of May, 1881.

The third American species reared under glass is the following very
interesting bombyx: _Ceratocampa (Eacles) imperialis_. The pupæ of
this species are rough, and armed with small, sharp points at all the
segments; the last segment having a thick, straight, and bifid tail. The
moths, which measure from four to about six inches in expanse of wings,
are bright yellow, with large patches and round spots of reddish-brown,
with a purple gloss; besides these patches and round spots, the wings
are covered with small dark dots. The male moth is much more blotched
than the female, and although of a smaller size, is much more showy than
the female.

With twenty-four pupæ of Imperialis I obtained nineteen moths from the
21st of June to the 19th of July; five pupæ died. Two pairings took
place; the first from the evening of the 13th to the morning of the
14th; the second from the evening of the 15th to the morning of the 16th
of July.

The ova, which are about the size of those of Yama-mai, Pernyi, or
Mylitta, are rather flat and concave on one side, of an amber-yellow
color and transparent, like those of sphingidæ. When the larvæ have
absorbed the yellow liquid in the egg, and are fully developed; they can
be seen through the shell of the egg, which is white or colorless when
the larva has come out.

The larvæ of Imperialis, which have six stages, commenced to hatch on
the 31st of July; the second stage commenced on the 7th of August; the
third, on the 17th; the fourth, on the 29th of August; the fifth, on
the 18th of September; and the sixth, on the 1st of October. The larvæ
commenced to pupate on 13th of October.

The larvæ of this curious species vary considerably in color. Some are
of a yellowish color, others are brown and tawny, others are black or
nearly black. My correspondent in Georgia, who bred this species the
same season as I did, in 1881, had some of the larvæ that were green. In
all the stages the larvæ have five conspicuous spines or horns; two on
the third segment, two on the fourth, and one on the last segment but
one; this is taking the head as the first segment with regard to the
first four spines These spines are rough and covered with sharp points
all round, and their extremities are fork-like. In the first three
stages they are horny; in the last three stages these spines are fleshy,
and much shorter in proportion than they are in the first three
stages. The color of the spines in the last three stages is coral-red,
yellowish, or black. In the fifth and sixth stages the spine on the last
segment but one is very short.

Here are a few and short notes from my book:

1st stage. Larvæ, about one-third of an inch; head, brown, shiny, and
globulous.

2d stage. Larvæ, dark-brown, almost black; spines, white at the base,
and black at the extremities; head shiny and light brown.

3d stage. Larve, fine black; head black; white hairs on the back;
spines, whitish, buff, or yellowish at the base, and black at the
extremities; other larvæ of a brown color.

4th stage. Larvæ, black granulated with white; long white hairs; horns,
brown-orange with white tips; on each segment two brown spots. Spiracles
well marked with outer circle, brown, then black; white and black dot in
the center. Anal segment with brown ribs, the intervals black with white
dots; head shining, black with two brown bands on the face, forming a
triangle. Other larvæ in fourth stage, velvety black, with coral-red
spines; others with black spines.

5th stage. Larvæ, entirely black, with showy eye-like spiracles,
polished black head; other larvæ having the head brown and black. Larvæ
covered with long white hair; spines black or red. No difference noticed
between the fifth and sixth stages.

One larva on fourth stage was different from all others, and was
described at the British Museum by Mr. W. F. Kirby as follows: "Larva
reddish-brown, sparingly clothed with long slender white hairs, with
four reddish stripes on the face, two rows of red spots on the back,
spiracles surrounded with yellow, black and red rings; legs red, prolegs
black, spotted with red. On segments three and four are four long
coral-red fleshy-branched spines, two on each segment, below which, on
each side, are two rudimentary ones just behind the head; in front of
segment two are four similar rudimentary orange spines or tubercles;
last segment black, strongly granulated and edges triangularly above and
at the sides, with coral-red; several short rudimentary fleshy spines
rising from the red portion; the last segment but one is reddish above,
with a short red spine in the middle, and the one before it has a long
coral-red spine in the middle similar to those of segments three and
four, but shorter"

As soon as my Imperialis larvæ had hatched, I gave them various kinds of
foliage, plane-tree, oak, pine, sallow, etc. At first they did not touch
any kind of foliage, or they did not seem to touch any; and I was afraid
I should be unable to rear them; but on the second or third day of their
existence, they made up their minds and decided upon eating the foliage
of some of the European trees I had offered them. They attacked oak,
sallow, and pine, but did not touch the plane-tree leaves. In America,
the larvæ of Imperialis feed on button-wood, which is the American
plane-tree (_Platanus occidentalis_), yet they did not take to _Platanus
orientalis_. After a little time I reduced the foliage to oak and sallow
branches, and ultimately gave them the sallow (_Salix caprea_) only, on
which they thrived very well. I was pleased with this success; as I had
previously read in a volume of the "Naturalist's Library" a description
of _Ceratocampa imperialis_, which ends as follows: "The caterpillars
are not common, and are the most difficult to bring to perfection in
confinement, as they will not eat in that situation; and, even if they
change into a chrysalis, they die afterward."

Before I finish with _C. imperialis_, I must mention a peculiar fact.
During the first stage, and, I think, also during the second, several
larvæ disappeared without leaving any traces. I also saw two smaller
larvæ held tight by the hind claspers of two larger ones. The larvæ thus
held and pressed were perfectly dead when I observed them, and I removed
them. My impression then was that these larvae were carnivorous, not
from this last fact alone, as I had previously observed it with larvæ
of Catocalæ when they are too crowded, but from the fact that some had
disappeared entirely from the glass under which they were confined. I
began to reduce their numbers, and put six only under each glass, so as
to be able to watch them better. Whether I had made a mistake or not
previously to this I do not exactly know; but from this moment the
larvae behaved in a most exemplary manner, especially when they became
larger. They crawled over each other's backs without the least sign of
spite or animosity, even when they were in sleep, in which case larvæ
are generally very sensitive and irritable, all were of a most pacific
nature. It is, therefore, with the greatest pleasure that, for want of
sufficient evidence, I withdraw this serious charge of cannibalism which
I first intended to bring against them.

From what has been said respecting the rearing of exotic silk-producing
bombyces, especially tropical species, it must have been observed
that several difficulties, standing in the way of success, have to be
overcome. The moths of North American species emerge regularly enough
during the months of May, June, or July, but Indian and other tropical
species may emerge at any time of the year, if the weather is mild, as
has been the case during this unusually mild winter of 1881-1882. From
the end of December to the present time (March 14, 1882) moths of four
species of Indian silk-producers, especially _Antheræa roylei_ and
_Actias selene_, have constantly emerged, but only one or two at a time.
These moths emerged from cocoons received in December and January last.

It is only when these tropical species shall have been already reared in
Europe that the emergence of the moths will be regular; then they will
be single-brooded in Northern or Central Europe, and some will very
likely become double-brooded in Southern Europe. But when just imported
the moths of these tropical species will always be uncertain and
irregular in their emergence; hence the importance of having a
sufficient number of cocoons so as to meet this difficulty, i.e., the
loss of the moths that emerge prematurely or irregularly.

Before I conclude, I shall repeat what I already stated in a previous
report, that the sending of live cocoons and pupæ from India and other
distant countries to Europe, can easily be done, so that they will
arrive alive and in good condition, if care be taken that the boxes
containing these live cocoons and pupæ should not be left in the sun or
near a fire (which has been the case before), and that they should at
once be put in a cool place or in the ice-room of the steamer. The
cocoons and pupæ should be sent from October to March or April,
according to distance, and it is most important to write on the cases,
"Living silkworm cocoons or pupæ, the case to be placed in the ice
room."

By taking this simple precaution, live cocoons and pupæ, when newly
formed, can be safely sent from very distant countries of Europe.

To continue these interesting and useful studies, I shall always be glad
to buy any number of live cocoons, or exchange them for other species,
if preferable.

ALFRED WAILLY.

110 Clapham Road, London, S.W.

       *       *       *       *       *




MOSQUITO OIL.


A correspondent from Sheepshead Bay, a place celebrated for the size of
its mosquitoes and the number of its amateur fishermen, recommends the
following as a very good mixture for anointing the face and hands while
fishing:

  Oil of tar.           1 ounce.
  Olive oil.            1 ounce.
  Oil of pennyroyal.    ½ ounce.
  Spirit of camphor.    ½ ounce.
  Glycerine.            ½ ounce.
  Carbolic acid.        2 drachms.

Mix. Shake well before using.--_Drug. Circular_.

       *       *       *       *       *




THE CATHEDRAL OF BURGOS.


This most remarkable structure, in the province of the same name, adorns
the city of Burgos, 130 miles north of Madrid. The corner stone was laid
July 20, A.D. 1221, by Fernando III., and his Queen Beatrice, assisted
by Archbishop Mauricio. The world is indebted to Mauricio for the
selection of the site, and for the general idea and planning of what he
intended should be, and in fact now is, the finest temple of worship in
the world. This immense stone structure, embellished with airy columns,
pointed arches, statues, inscriptions, delicate crestings, and flanked
by two needles or aerial arrows, rises toward the heavens, a sublime
invocation of Christian genius.

Illuminated by the morning sun it appears, at a certain distance, as if
the pyramids were floating in space; further on is seen the marvelous
dome of the transept, crowned with eight towers of chiseled lace-work,
over the center of the church.

Pubic worship was held in a portion of the edifice nine years after the
work was begun; from that time onward for three hundred years, various
additional portions were completed. On March 4, 1539, the great
transept, built fifty years previous, fell down; but was soon restored.
August 16, 1642, at 6½ o'clock, P.M., a furious hurricane overthrew the
eight little towers that form the exterior corner of the dome; but in
two years they were replaced, namely July 19, 1644: the same night the
great bells sounded an alarm of fire, the transept having in some way
become ignited. The activity of the populace, however, prevented the
loss of the edifice, which for a time was in great danger.

The first architect publicly mentioned in the archives of the edifice
was the Master Enrique. He also directed the work of the Cathedral of
Leon. He died July 10, 1277. The second architect was Juan Perez, who
died in 1296, and was buried in the cloister, under the cathedral. He is
believed to have been either the son or brother of the celebrated Master
Pedro Perez, who designed the Cathedral of Toledo, and who died in 1299.
The third architect of the Cathedral of Burgos was Pedro Sanchez, who
directed the work in 1384; after him followed Juan Sanchez de Molina,
Martin Fernandez, the three Colonias, Juan de Vallejo, Diego de Siloe,
the elder Nicolas de Vergara, Matienzo, Pieredonda, Gil, Regines, and
others. It is worthy of note that a number of Moorish architects were
employed on the work during the 14th and 15th centuries, such as
Mohomad, Yunce, the Master Hali, the Master Mahomet de Aranda, the
Master Yunza de Carrion, the Master Carpenter Brahen. Among the figure
sculptors employed were Juan Sanchez de Fromesta, the Masters Gil and
Copin, the famous Felipe de Vigardi, Juan de Lancre, Anton de Soto, Juan
de Villareal, Pedro de Colindres, and many others. Our engraving is from
a recent number of _La Ilustracion Espanola y Americana_.

[Illustration: THE CATHEDRAL OF BURGOS, SPAIN.--PHOTOGRAPH BY DE
LAURENT.--DRWAWING BY M. HEBERT.]

       *       *       *       *       *




THE PANAMA CANAL.

By MANUEL EISSLER, M.E., of San Francisco, Cal.

I.

HISTORICAL NOTES.


When Cortez, in the year 1530, made the observation that the two great
oceans could be seen from the peaks of mountains, he, in those remote
days, preoccupied himself with the question to cut through the
Cordilleras.

Therefore, the idea of an interoceanic canal is by no means a modern
one, as travelers and navigators observed that there was a great
depression among the hills of the Isthmus of Panama. As Professor T.E.
Nurse, of the U.S.N., says in his memoirs:

"This problem of interoceanic communication has been justly said to
possess not only practical value, but historical grandeur. It clearly
links itself back to the era of the conquest of Cortez, three and a half
centuries." [1] It is a problem which has been left for our modern era
to solve, but nevertheless its history is thereby rendered still more
interesting, having needed so many centuries to bring it to an issue.

[Footnote 1: From Prof. Nurse's historical essay. See Survey of
Nicaragua Canal, by Com. Lull.]

Spain, which acquired through her Columbus a new empire, lying near, as
it was supposed, to the riches of Asia, could not be indifferent, from
the moment of her discoveries, to the means of crossing these lands to
yet richer ones beyond.

India, from the days of Alexander and of the geographers, Mela, Strabo,
and Ptolemy, was the land of promise, the home of the spices, the
inexhaustible fountain of wealth. The old routes of commerce thither had
been closed one by one to the Christians; the overland trade had fallen
into the hands of the Arabs; and at the fall of Constantinople, 1453,
the commerce of the Black Sea and of the Bosphorus, the last of the old
routes to the East, finally failed the Christian world. Yet even beyond
the fame of the East, which tradition had brought down from Greek and
Roman, much more had the crusaders kindled for Asia (Cathay) and its
riches an ardor not easily suppressed in men's minds.

The error of the Spanish Admiral in supposing that the eastern shores
of Asia extended 240 degrees east of Spain, or to the meridian of
the modern San Diego, in California--this error, insisted on in his
dispatches and adopted and continued by his followers, still further
animated the earlier Spanish sovereigns and the men whom they sent into
the New World to reach Asia by a short and easy route.

Nobody in Europe dreamt that Columbus had discovered a new continent,
and when Balbao, in 1513, discovered the South Sea, then it was known
that Asia lay beyond, and navigators directed their course there. On
his deathbed, in 1506, Columbus still held to his delusion that he had
reached Zipanga, Japan. In 1501 he was exploring the coast of Veragua,
in Central America, still looking for the Ganges, and announcing his
being informed on this coast of a sea which would bear ships to the
mouth of that river, while about the same time the Cabots, under Henry
VII., were taking possession of Newfoundland, believing it to be part of
the island coast of China.

Although these were grave blunders in geography and in navigation, the
discoveries really made in the rich tropical zones, the acquirement of
a new world, and the rich products continually reaching Europe from it,
for a time aroused Spain from her lethargy. The world opened east and
west. The new routes poured their spices, silks, and drugs through new
channels into all the Teutonic countries. The strong purposes of having
near access to the East were deepened and perpetuated doubly strong, by
the certainties before men's eyes of what had been attained.

Balbao, in 1513, gained from a height on the Isthmus of Panama the first
proof of its separation from Asia; and Magellan enters the South Sea
at the southern extremity of the country, now first proven to be thus
separate and a continent. Men in those days began to think that creation
was doubled, and that such discovered lands must be separate from India,
China, and Japan. And the very successes of the Portuguese under Vasco
da Gama, bringing from their eastern course the expectancy of Asia's
wealth, intensely excited the Spaniards to renew their western search.

The Portuguese, led around the Cape of Good Hope, had brought home vast
treasures from the East, while the Spanish discoverers, as yet, had not
reached the countries either of Montezuma or of the Inca. Their success
"troubled the sleep of the Spaniards."

Everything, then, of personal ambition and national pride, the thirst
for gold, the zeal of religious proselytism, and the cold calculations
of state policy, now concurred in the disposition to sacrifice what
Spain already had of most value on the American shores in order to seize
upon a greater good, the Indies, still supposed to be near at hand. And
since it was now certain that the new lands were not themselves Asia,
the next aim was to find the secret of the narrow passage across
them which must lead thither. The very configuration of the isthmus
strengthened the belief in the existence of such a passage by the number
of its openings, which seemed to invite entrance in the expectancy that
some one of them must extend across the narrow breadth of land.

For this the Spanish government, in 1514, gave secret orders to
D'Avilla, Governor of Castila del Oro, and to Juan de Solis, the
navigator, to determine whether Castila del Oro were an island, and to
send to Cuba a chart of the coast, if any strait were possible. For
this, De Solis visited Nicaragua and Honduras; and later, led far to the
south, perished in the La Plata. For this, Magellan entered the straits,
which, strangely enough, he affirmed before setting out, that he "would
enter," since he "had seen them marked out on the geographer Martin
Behaim's globe." For this, Cortez sent out his expeditions on both
coasts, exposing his own life and treasure, and sending home to the
emperor, in his second relation, a map of the entire Gulf of Mexico
(Dispatch from Cortez to Charles V., October 15, 1524). For this great
purpose, and in full expectancy of success in it, the whole coast of
the New World on each side, from Newfoundland on the northeast, curving
westward on the south, around the whole sweep of the Gulf of Mexico,
thence to Magellan's Straits, and thence through them up the Pacific to
the Straits of Behring, was searched and researched with diligence.
"Men could not get accustomed," says Humboldt, "to the idea that the
continent extended uninterruptedly both so far north and south." Hence
all these large, numerous, and persevering expeditions by the European
powers.

Among them, by priority of right and by her energy, was Spain. The great
emperor was urgent on the conqueror of Mexico, and on all in subordinate
positions in New Spain, to solve the secret of the strait. All Spain was
awakened to it. "How majestic and fair was she," says Chevalier, "in the
sixteenth century; what daring, what heroism and perseverance! Never had
the world seen such energy, activity, or good fortune. Hers was a will
that regarded no obstacles. Neither rivers, deserts, nor mountains far
higher than those in Europe, arrested her people. They built grand
cities, they drew their fleets, as in a twinkling of the eye, from the
very forests. A handful of men conquered empires. They seemed a race of
giants or demi-gods. One would have supposed that all the work necessary
to bind together climates and oceans would have been done at the word of
the Spaniards as by enchantment, and since nature had not left a passage
through the center of America, no matter, so much the better for
the glory of the human race; they would make it up by artificial
communication. What, indeed, was that for men like them? It were done
at a word. Nothing else was left for them to conquer, and the world was
becoming too small for them."

Certainly, had Spain remained what she then was, what had been in vain
sought from nature would have been supplied by man. A canal or several
canals would have been built to take the place of the long-desired
strait. Her men of science urged it. In 1551, Gomara, the author of the
"History of the Indies," proposed the union of the oceans by three of
the very same lines toward which, to this hour, the eye turns with hope.

"It is true," said Gomara, "that mountains obstruct these passes, but if
there are mountains there are also hands; let but the resolve be made,
there will be no want of means; the Indies, to which the passage will
be made, will supply them. To a king of Spain, with the wealth of the
Indies at his command, when the object to be obtained is the spice
trade, what is possible is easy.

But the sacred fire suddenly burned itself out in Spain. The peninsula
had for its ruler a prince who sought his glory in smothering free
thought among his own people, and in wasting his immense resources in
vain efforts to repress it also outside of his own dominions through all
Europe. From that hour, Spain became benumbed and estranged from all
the advances of science and art, by means of which other nations, and
especially England, developed their true greatness.

Even after France had shown, by her canal of the south, that boats could
ascend and pass the mountain crests, it does not appear that the
Spanish government seriously wished to avail itself of a like means of
establishing any communication between her sea of the Antilles and the
South Sea. The mystery enveloping the deliberations of the council of
the Indies has not always remained so profound that we could not know
what was going on in that body. The Spanish government afterward opened
up to Humboldt free access to its archives, and in these he found
several memoirs on the possibility of a union between the two oceans;
but he says that in no one of them did he find the main point, the
height of the elevations on the isthmus, sufficiently cleared up, and
he could not fail to remark that the memoirs were exclusively French or
English. Spain herself gave it no thought. Since the glorious age of
Balbao among the people, indeed, the project of a canal was in every
one's thoughts. In the very wayside talks, in the inns of Spain, when a
traveler from the New World chanced to pass, after making him tell of
the wonders of Lima and Mexico, of the death of the Inca, Atahualpa,
and the bloody defeat of the Aztecs, and after asking his opinion of El
Dorado, the question was always about the two oceans, and what great
things would happen if they could succeed in joining them.

During the whole of the seventeenth and eighteenth centuries, Spain
had need of the best mode of conveyance for her treasures across the
isthmus. Yet those from Peru came by the miserable route from Panama to
the deadliest of climates. Porto Bello and her European wares for
her colonies toiled up the Chagres river, while the roughest of
communication farther north connected the Chimalapa and the Guasacoalcos
in Mexico, and the trade there was limited sternly to but one port on
each side. As late as Humboldt's visit, in 1802, when remarking upon the
"unnatural modes of communication" by which, through painful delays, the
immense treasures of the New World passed from Acapulco, Guayaquil,
and Lima, to Spain, he says: "These will soon cease whenever an active
government, willing to protect commerce, shall construct a good road
from Panama to Porto Bello. The aristocratic nonchalance of Spain, and
her fear to open to strangers the way to the countries explored for her
own profit, only kept those countries closed." The court forbade, on
pain of death, the use of plans at different times proposed. They
wronged their own colonies by representing the coasts as dangerous and
the rivers impassable. On the presentation of a memoir for improving the
route through Tehuantepec, by citizens of Oaxaca, as late as 1775,
an order was issued forbidding the subject to be mentioned. The
memorialists were censured as intermeddlers, and the viceroy fell under
the sovereign's displeasure for having seemed to favor the plans.

The great isthmus was, however, further explored by the Spanish
government for its own purposes; the recesses were traversed, and the
lines of communication which we know to-day were then noted.

In addition to the fact that comparatively little was explored north or
south of that which early became the main highway, the Panama route,
there is confirmation here of the truth that Spain concealed and even
falsified much of her generally accurately made surveys. No stronger
proof of this need be asked than that which Alcedo gives in connection
with the proposal by Gogueneche, the Biscayan pilot, to open
communication by the Atrato and the Napipi. "The Atrato," says the
historian, "is navigable for many leagues, but the navigation of it is
prohibited under pain of death, without the exception of any person
whatever."

The Isthmus of Nicaragua has always invited serious consideration for
a ship canal route by its very marked physical characteristics, among
which is chiefly its great depression between two nearly parallel ranges
of hills, which depression is the basin of its large lake, a natural and
all-sufficient feeder for such a canal.

In 1524 a squadron of discovery sent out by Cortez on the coast of the
South Sea, announced the existence of a fresh water sea at only
three leagues from the coast; a sea which, they said, rose and fell
alternately, communicating, it was believed, with the Sea of the North.
Various reconnoissances were therefore made, under the idea that here
the easy transit would be established between Spain and the spice lands
beyond.

It was even laid down on some of the old maps, that this open
communication by water existed from sea to sea; while later maps
represented a river, under the name of Rio Partido, as giving one of
its branches to the Pacific Ocean and the other to Lake Nicaragua. An
exploration by the engineer, Bautista Antonelli, under the orders of
Philip II., corrected the false idea of an open strait.

In the eighteenth century a new cause arose for jealousy of her
neighbors and for keeping her northern part of the isthmus from their
view. In the years 1779 and 1780 the serious purposes of the English
government for the occupancy of Nicaragua, awakened the solicitudes of
the Spanish government for this section. The English colonels, Hodgson
and Lee, had secretly surveyed the lake and portions of the country,
forwarding their plans to London, as the basis of an armed incursion,
to renew such as had already been made by the superintendent of the
Mosquito coast, forty years before, when, crossing the isthmus, he took
possession of Realejo, on the Pacific, seeking to change its name to
Port Edward. In 1780, Captain, afterward Lord Nelson, under orders from
Admiral Sir Peter Parker, convoyed a force of two thousand men to San
Juan de Nicaragua, for the conquest of the country.

In his dispatches, Nelson said: "In order to give facility to the great
object of government, I intend to possess the lake of Nicaragua, which,
for the present, may be looked upon as the inland Gibraltar of Spanish
America. As it commands the only water pass between the oceans, its
situation must ever render it a principal post to insure passage to the
Southern Ocean, and by our possession of it Spanish America is severed
into two."

The passage of San Juan was found to be exceedingly difficult; for the
seamen, although assisted by the Indians from Bluetown, scarcely forced
their boats up the shoals. Nelson bitterly regretted that the expedition
had not arrived in January, in place of the close of the dry season. It
was a disastrous failure, costing the English the lives of one thousand
five hundred men, and nearly losing to them their Nelson.

At this period, Charles III., of Spain, sent a commission to explore the
country. These commissioners reported unfavorably as regarded the route;
but fearing further intrusion from England, forbade all access to the
coast; even falsifying and suppressing its charts and permanently
injuring the navigation of the San Juan and the Colorado by obstructions
in their beds.

It is, however, a relief here to learn that when Humboldt visited the
New World, he could say: "The time is passed when Spain, through a
jealous policy, refused to other nations a thoroughfare across the
possessions of which they kept the whole world so long in ignorance.
Accurate maps of the coasts, and even minute plans of military
positions, are published." It is also true that the Spanish Cortes,
in 1814, decreed the opening of a canal, a decree deferred and never
executed.

It was reserved for our century to see this great project carried into
execution, and it is but just that as a chronicler of events I should
connect with the Canal of Panama the name of a family who have done much
to bring the scheme, so to say, into practical execution.

As early as the year 1836, Mr. Joly de Sabla turned his views toward the
cutting of a canal across the Isthmus of Panama. He resided at the time
on the Island of Guadeloupe, one of the French West India Islands,
where he possessed large estates. Of a high social position, the
representative of one of France's ancient and noble families, with large
means at his disposal and of an enterprising spirit much in advance of
his time, he was well calculated to carry out such a grand scheme.

He soon set about procuring from the Government of New Granada (now
Colombia) the necessary grants and concessions, but much time and many
efforts were spent before these could be brought to a satisfactory
condition, and it was not until the year 1841 that he could again visit
the Isthmus, bringing with him this time, on a vessel chartered by him
for the purpose, a corps of engineers and employes, medical staff, etc.,
etc. After two years spent in exploring and surveying a country at that
time very imperfectly known, he returned to Guadeloupe to find his
residence and most of his estates destroyed by the terrible earthquake
that visited the island in February, 1843.

Undaunted by this unexpected and severe blow, Mr. De Sabla persisted in
his efforts, and in the same year obtained from the French government
the establishment of a Consulate at Panama to insure protection to the
future canal company, and also the sending of two government engineers
of high repute (Messrs. Garella and Courtines), to verify the surveys
already made and complete them.

After receiving the respective reports of Garella and Courtines, Mr.
De Sabla decided upon first constructing a railway across the Isthmus,
postponing the cutting of the canal until this indispensable auxiliary
should have rendered it practicable and profitable. He then presented
the scheme in that shape to his friends in Paris and London, and formed
a syndicate of thirteen members, among whom we may recall the names of
the well known Bankers Caillard of Paris, and Baimbridge of London,
of Sir John Campbell, then Vice President of the Oriental Steamship
Company, of Viscount Chabrol de Chameane, and of Courtines, the
exploring engineer.

A new contract was then entered upon with New Granada in June, 1847, and
early in 1848, the Syndicate was about to forward to the Isthmus the
expedition which was to execute the preliminary works, while the company
was being finally organized in Paris, and its stock placed.

The success of the undertaking seemed to be assured beyond peradventure,
when the unexpected breaking out of the French revolution in February,
1848, dashed all hopes to the ground. Several of the prominent
financiers engaged in the affair, taken by surprise by the suddenness of
the revolution, had to suspend their payments and of course to withdraw
from the Panama Canal and railroad scheme. Others withdrew from
contagious fear and timidity. Finally the term fixed for carrying out
certain obligations of the contract expired without their fulfillment
by the company, and the concession was forfeited. Another contract was
almost immediately applied for and granted with unseemly haste by the
President of New Granada to Messrs. Aspinwall, Stephens and Chauncey,
which resulted in the construction of the actual Panama Railroad.

These gentlemen acted fairly in the matter, and in 1849, calling Mr.
De Sabla to New York, offered him to join them in the new scheme.
Unfortunately they had decided upon placing the Atlantic terminus of the
railroad upon the low and swampy mud Island of Manzanillo, while Mr.
De Sabla insisted on having it on the mainland on the dry and healthy
northern shore of the Bay of Limon. They could not come to an
understanding on this point, and Mr. De Sabla, whose experience and
foresight taught him the dangers that would result to the shipping from
the unprotected situation of the projected part (now Colon--Aspinwall),
and who well knew the insalubrity of the malarial swamp constituting
the Island of Manzanillo, withdrew forever from the undertaking, after
having devoted to it without any benefit to himself, the best years of
his life and a large portion of his private means.

One of his sons, Mr. Theodore J. de Sabla, after having actively
co-operated with Lieutenant Commander Wyse, in the original scheme
of the present canal company, is now one of Count de Lesseps's
representatives in the City of New York, and a director of the Panama
Railroad Company.

       *       *       *       *       *




IMPROVED AVERAGING MACHINE.


At the recent meeting of the American Society of Civil Engineers, in
this city, a paper on an improved form of the averaging machine was read
by its inventor, Mr. Wm. S. Auchincloss.

The ingenious method by which the weight of the platform is eliminated
from the result of the work of the machine was exhibited and explained.
This is accomplished by counterweights sliding automatically in tubes,
so that in any position the unloaded platform is always in equilibrium.
Any combination of representative weights can then be placed on this
platform at the proper points of the scale. By then drawing the platform
to its balancing point, the location of the center of gravity will at
once be indicated on the scale by the pointer over the central trunnion.

The weights may be arranged on a decimal system, with intermediate
weights for closer working, or they may be made so as to express
multiples or factors.

Each machine is provided with a number of differing scales, divided
suitably for various purposes. When the problem is one of time, the
scale represents months and days; for problems of proportion, the zero
of the scale is at the center of its length; for problems for the
location of center of gravity of a system from a fixed point, the zero
is at the extremity of the scale, etc.

The machine exhibited has sixty-three transverse grooves, which, by
arrangement of weights, can be made to serve the purposes of two hundred
and fifty-two grooves.

The machine is 29 inches in length, 9 inches in width, and weighs about
13 pounds.

With the machine can be found average dates, as, for instance, of
purchases and of payments extending over irregular periods; also average
prices, as for "futures," in comman use among cotton brokers. The
problem of average haul, so often presented to the engineer, can be
solved with ease and great celerity. Practical examples of the solution
of these and a number of other problems involving proportions or
averages were given by the author.

       *       *       *       *       *




COMPOUND BEAM ENGINE.


The engine represented in Figs. 1 to 4 herewith is intended for a mill,
and is of 530 to 800 indicated horse-power, the pressure being seven
atmospheres, and the number of revolutions forty-five per minute. As
will be seen by the drawing each cylinder is placed in a separate
foundation plate, the two connecting rods acting upon cranks keyed
at right angles upon the shaft, W, which carries the drum, T. The
high-pressure cylinder, C, is 760 mm diameter, the low pressure cylinder
being 1,220 mm. diameter, and the piston speed 2.28 m. The drum, which
also fulfills the purpose of a fly wheel, is provided with twenty-eight
grooves for ropes of 50 mm. diameter. With the exception of the
cylinders, pistons, valves, and valve chests, the engines are of the
same size, corresponding to the equal maximum pressures which come into
action in each cylinder, and in this respect alone the engine differs in
principle from an ordinary twin machine.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 1]

The steam passes from the stop-valve, A, Fig. 4, through the steam pipe,
D, to the high pressure cylinder, C, and having done its work, goes into
the receiver, R, where it is heated. From the receiver it is led into
the low-pressure cylinder, C1, and thence into the condenser. Provision
is made for working both engines independently with direct steam when
desired, suitable gear being provided for supplying steam of the proper
pressure to the condensing engine, so that each engine shall perform
exactly the same amount of work. The starting gear consists of a
hand-wheel, H, which controls the stop valve, A, and of another h, which
opens the valves for the jackets of the cylinders and receiver. The
hand-wheel, h1 and h2, govern the valves, which turn the steam direct
into the two cylinders. There are also lever, g, which opens the
principal injection cock, H1, and the auxiliary injection cock, H2, the
function of which is to assist in forming a speedy vacuum, when the
engine has been standing for some time.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 2]

The drum is 6.08 m. diameter, the breadth being 2.04 m., with a total
weight of 33,000 kilos. The beams are of cast iron with balance weights
cast on. The connecting rods and cross beams are of wrought iron, and
the cranks, crank shaft, piston rods, valve rods, etc., of steel. The
bed-plate for the main shaft bearings are cast in one piece with the
standards for the beam, which are connected firmly together by the
center bearing, M M1, which is cast in one piece, and also by the
diagonal bracing piece, N N1. The construction of the cylinder and valve
chests is shown in Fig. 1. The working cylinder is in the form of a
liner to the cylinder, thus forming the steam jacket, with a view to
future renewal. This lining has a flange at the lower part for bolting
it down, being made steam-tight by the intervention of a copper packing
ring. There is a similar ring at the upper part which is pressed down by
the cylinder cover. The latter is cast hollow and strengthened by ribs.
The pistons are provided with cast iron double self-expanding packing
rings. For preventing accidents by condensed water, spring safety
valves, ss and s1 s1, are connected to the valve chests. The valve gear,
which is arranged in the same manner for both cylinders, is actuated
by shafts, w and w1, rotated by toothed wheels as shown. Motion is
communicated from the way-shafts, w and w1, by the eccentrics, and the
eccentric rods, e1 e2 e3 e4, and the levers and rods belonging thereto,
to the short steam valve rocking shafts levers, f1 f2 f3 f4, and the
exhaust valve rocking shafts, k1 k2 k3 k4, the bearings of which are
carried on brackets above the valve chests, which, being furnished with
tappet levers, raise and lower the valves.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 3]

The valves are conical, double-seated, and of cast iron, and the inlet
and outlet valves are placed the one above the other, the seats being
also conically ground and inserted through the cover of the valve chest.
Both inlet and outlet valves are actuated from above, and are removable
upward, an arrangement which admits of the valves being more easily
examined than when the two are actuated from different sides of the
valve chest. To carry out this idea the inlet valves are furnished with
two guides, which, passing upward through the stuffing-box, are attached
to a hard steel cross piece, which receives the action of a bent catch
turning on a pin attached to the levers, t1, t2, t3, t4. The exhaust
valves, on the contrary, have only one guide each, which passes upward
through the seat of the admission valve, through the valve itself by
means of a collar, and through the stuffing-box. It is furnished with
hard steel armatures, through which the levers, z1 z2, Fig. 3, act upon
the exhaust valves.

[Illustration: BORSIG'S IMPROVED COPOUND BEAM ENGINE. FIG. 4]

The governor effects the acceleration or retardation of the loosening of
the catch actuating the steam valve by means of hard steel projections
on the shaft, v1, the position of which, by means of levers, is
regulated by the governor, which in its highest position does not allow
the lifting of the inlet valve at all. The regulation of the expansion
by the governor from 0 to 0.45 takes place generally only in the case of
the high-pressure cylinder, while the low-pressure cylinder has a fixed
rate of expansion. Only when the low-pressure cylinder is required
to work with steam direct from the boiler is the governor applied to
regulate the expansion in it. An exact action in the valve guides and
a regular descent is secured by furnishing them with small dash pot
pistons working in cylinders. Into them the air is readily admitted by
a small India-rubber valve, but the passage out again is controlled at
pleasure.--_The Engineer_.

       *       *       *       *       *

TO DETECT ALKALIES IN NITRATE OF SILVER--Stolba recommends the salt
to be dissolved in the smallest quantity of water, and to add to
the filtered solution hydrofluosilicic acid, drop by drop. Should a
turbidity appear an alkaline salt is present. But should the liquid
remain limpid, an equal volume of alcohol is to be added, which will
cause a precipitate in case the slightest trace of an alkali be present.

       *       *       *       *       *




POWER HAMMERS WITH MOVABLE FULCRUM.

[Footnote: Paper read before the Institution of Mechanical
Engineers.--_Engineering_.]

By DANIEL LONGWORTH, of London.


The movable-fulcrum power hammer was designed by the writer about five
and a half years ago, to meet a want in the market for a power hammer
which, while under the complete control of only one workman, could
produce blows of varying forces without alteration in the rapidity with
which they were given. It was also necessary that the vibration and
shock of the hammer head should not be transmitted to the driving
mechanism, and that the latter should be free from noise and liability
to derangement. The various uses to which the movable fulcrum hammers
have been put, and their success in working[1]--as well as the
importance of the general subject which includes them, namely, the
substitution of stored power for human effort--form the author's excuse
for now occupying the time of the meeting.

[Footnote 1: The hammers have been for some years used by A. Bamlett, of
Thirsk; the American Tool Company, of Antwerp; Messrs. W.&T. Avery, of
Birmingham; Pullar & Sons, of Perth; Salter & Co., of West Bromwich;
Vernon Hope & Co., of Wednesbury, etc.; and also for stamps by Messrs.
Collins & Co., of Birmingham, etc.]

Until these hammers were introduced, no satisfactory method had been
devised for altering the force of the blow. The plan generally adopted
was to have either a tightening pulley acting on the driving belt, a
friction driving clutch, or a simple brake on the driving pulley, put in
action by the hand or foot of the workman. Heavy blows were produced
by simply increasing the number of blows per minute (and therefore the
velocity), and light blows by diminishing it--a plan which was quite
contrary to the true requirements of the case. To prevent the shock
of the hammer head being communicated to the driving gear, an elastic
connection was usually formed between them, consisting of a steel spring
or a cushion of compressed air. With the steel spring, the variation
which could be given in the thickness of the work under the hammer was
very limited, owing to the risk of breaking the spring; but with the
compressed air or pneumatic connection the work might vary considerably
in thickness, say from 0 to 8 in. with a hammer weighing 400lb. The
pneumatic hammers had a crank, with a connecting rod or a slotted
crossbar on the piston-rod, a piston and a cylinder which formed the
hammer-head. The piston-rod was packed with a cup leather, or with
ordinary packing, the latter required to be adjusted with the greatest
nicety, otherwise the piston struck the hammer before lifting it, or
else the force of the blow was considerably diminished. As the piston
moved with the same velocity during its upward and downward strokes,
and, in the latter, had to overtake and outrun the hammer falling under
the action of gravity, the air was not compressed sufficiently to give
a sharp blow at ordinary working speeds, and a much heavier hammer was
required than if the velocity of the piston had been accelerated to a
greater degree.

As it is impossible in the limits of this paper to describe all the
forms in which the movable fulcrum hammers have been arranged, two types
only will be selected taken from actual work; namely, a small planishing
hammer, and a medium-sized forging hammer.[1]

[Footnote 1: To the makers, Messrs. J. Scott Rawlings & Co, of
Birmingham, the author is indebted for the working drawings of these
hammers.]

The small planishing hammer, Figs. 1 to 3, next page, is used for
copper, tin, electro, and iron plate, for scythes, and other thin work,
for which it is sufficient to adjust the force of the blow once for all
by hand, according to the thickness and quality of the material before
commencing to hammer it. The hammer weighs 15 lb., and has a stroke
variable from 2½ in. to 9½ in., and makes 250 blows per minute. The
driving shaft, A, is fitted with fast and loose belt pulleys, the belt
fork being connected to the pedal, P, which when pressed down by the
foot of the workman, slides the driving belt on to the fast pulley and
starts the hammer; when the foot is taken off the pedal, the weight on
the latter moves the belt quickly on to the loose pulley, and the hammer
is stopped. The flywheel on the shaft, A, is weighted on one side,
so that it causes the hammer to stop at the top of its stroke after
working; thus enabling the material to be placed on the anvil before
starting the hammer. The movable fulcrum, B, consists of a stud, free to
slide in a slot, C, in the framing, and held in position by a nut and
toothed washer. On the fulcrum is mounted the socket, D, through which
passes freely a round bar or rocking lever, E, attached at one end to
the main piston, F, of the hammer, G, and having at the other extremity
a long slide, H, mounted upon it. This slide is carried on the
crank-pin, I, fastened to the disk, J, attached to the driving shaft, A.
The crank-pin, in revolving, reciprocates the rocking lever, E, and
main piston, F, and through the medium of the pneumatic connection, the
hammer, G. The slide, H, in revolving with the crank-pin, also moves
backward and forward along the rocking lever, approaching the fulcrum,
B, during the down-stroke of the hammer, and receding from it during
the up-stroke. By this means the velocity of the hammer is considerably
accelerated in its downward stroke, causing a sharp blow to be given
while it is gently raised during its upward stroke.

To alter the force of the blow, the hammer, G, is made to rise and fall
through a greater or less distance, as may be required, from the fixed
anvil block, K, after the manner of the smith giving heavy or light
blows on his anvil. It is evident that this special alteration of the
stroke could not be obtained by altering the throw of a simple crank and
connecting rod; but by placing the slot, C, parallel with the direction
of the rocking lever, E, when the latter is in its lowest position, with
the hammer resting on the anvil, and with the crank at the top of its
stroke, this lowest position of the rocking lever and hammer is made
constant, no matter what position the fulcrum, B, may have in the slot,
C. To obtain a short stroke, and consequently a light blow, the fulcrum
is moved in the slot toward the hammer, G; and to produce a long stroke
and heavy blow the fulcrum is moved in the opposite direction.

Fig. 3 gives the details of the pneumatic connection between the main
piston and the hammer, in which packing and packing glands are dispensed
with. The hammer, G, is of cast steel, bored out to fit the main piston,
F, the latter being also bored out to receive an internal piston, L. A
pin, M, passing freely through slots in the main piston, F, connects
rigidly the internal piston, L, with the hammer, G. When the main piston
is raised by the rocking lever, the air in the space, X, between the
main and internal pistons, is compressed, and forms an elastic medium
for lifting the hammer; when the main piston is moved down, the air in
the space, Y, is compressed in its turn, and the hammer forced down to
give the blow. Two holes drilled in the side of the hammer renew the air
automatically in the spaces, X and Y, at each blow of the hammer.

Figs. 4 to 6, on the next page, represent the medium size forging
hammer, for making forgings in dies, swaging and tilting bars, and
plating edged tools, etc.

The hammer weighs 1 cwt., has a stroke variable from 4 in. to 14½ in.,
and gives 200 blows per minute; the compressed air space between the
main piston and the hammer is sufficiently long to admit forgings up to
3 in. thick under the hammer.

To make forgings economically, it is necessary to bring them into the
desired form by a few heavy blows, while the material is still in a
highly plastic condition, and then to finish them by a succession of
lighter blows. The heavy blows should be given at a slower rate than the
lighter ones, to allow time for turning the work in the dies or on the
anvil, and so to avoid the risk of spoiling it. In forging with the
steam hammer the workman requires an assistant, who, with the lever
of the valve motion in hand, obeys his directions as to starting and
stopping, heavy or light blows, slow or quick blows, etc; the quickest
speed attainable depending on the speed of the arm of the assistant.
In the movable-fulcrum forging hammer the operations of starting and
stopping, and the giving of heavy or light blows, are under the complete
control of one foot of the workman, who requires therefore no assistant;
and by properly proportioning the diameter of the driving pulley and
size of belt to the hammer, the heavy blows are given at a slower rate
than the light ones, owing to the greater resistance which they offer to
the driving belt.

In this hammer the pneumatic connection, the arrangements for the
starting, stopping, and holding up of the hammer, as well as those for
communicating the motion of the crank-pin to the hammer by means of
a rocking lever and movable fulcrum, are similar to those in the
planishing hammer, differing only in the details, which provide double
guides and bearings for the principal working parts.

[Illustration: LONGWORTH'S POWER HAMMER WITH MOVABLE FULCRUM.]

The movable fulcrum, B, Figs. 4 and 5, consists of two adjustable steel
pins, attached to the fulcrum lever, Q, and turned conical where they
fit in the socket, D. The fulcrum lever is pivoted on a pin, R, fixed in
the framing of the machine, and is connected at its lower extremity
to the nut, S, in gear with the regulating screw, T. The to-and-fro
movement of the fulcrum lever, Q, by which heavy or light blows are
given by the hammer, is placed under the control of the foot of the
workman, in the following manner: U is a double-ended forked lever,
pivoted in the center, and having one end embracing the starting pedal,
P, and the other end the small belt which connects the fast pulley
on the driving shaft, A, with the loose pulley, V, or the reversing
pulleys, W and X. These are respectivly connected with the bevel wheels,
W_{1}, and X_{1}, gearing into and placed at opposite sides of the bevel
wheel, Z, on the regulating screw in connection with the fulcrum lever.
When the workman places his foot on the pedal, P, to start the hammer,
he finds his foot within the fork of the lever, U; and by slightly
turning his foot round on his heel he can readily move the forked
lever to right or left, so shifting the small belt on to either of the
reversing pulleys, W or X, and causing the regulating screw, T, to
revolve in either direction. The fulcrum lever is thus caused to move
forward or backward, to give light or heavy blows. By moving the forked
lever into mid position, the small belt is shifted into its usual place
on the loose pulley, V, and the fulcrum remains at rest. To fix the
lightest and heaviest blow required for each kind of work, adjustable
stops are provided, and are mounted on a rod, Y, connected to an arm of
the forked lever. When the nut of the regulating screw comes in contact
with either of the stops, the forked lever is forced into mid position,
in spite of the pressure of the foot of the workman, and thus further
movement of the fulcrum lever, in the direction which it was taking,
is prevented. The movable fulcrum can also be adjusted by hand to any
required blow, when the hammer is stopped, by means of a handle in
connection with the regulating screw.

In conclusion the author wishes to direct attention to the fact, that in
many of our largest manufactories, particularly in the midland counties,
foot and hand labor for forging and stamping is still employed to an
enormous extent. Hundreds of "Olivers," with hammers up to 60 lb. in
weight, are laboriously put in motion by the foot of the workman, at a
speed averaging fifty blows per minute; while large numbers of stamps,
worked by hand and foot, and weighing up to 120 lb., are also employed.
The low first cost of the foot hammers and stamps, combined with the
system of piece work, and the desire of manufacturers to keep their
methods of working secret, have no doubt much to do with the small
amount of progress that has been made; although in a few cases
competition, particularly with the United States of America, has forced
the manufacturer to throw the Oliver and hand-stamp aside, and to employ
steam power hammers and stamps. The writer believes that in connection
with forging and stamping processes there is still a wide and profitable
field for the ingenuity and capital of engineers, who choose to
occupy themselves with this minor, but not the less useful, branch of
mechanics.

       *       *       *       *       *




THE BICHEROUX SYSTEM OF FURNACES APPLIED TO THE PUDDLING OF IRON.


Since the year 1872, the large iron works at Ougrée, near Liege, have
applied the Bicheroux system of furnaces to heating, and, since the
year 1877, to puddling. The results that have been obtained in this
last-named application are so satisfactory that it appears to us to be
of interest to speak of the matter in some detail.

The apparatus, which is shown in the opposite page, consists of three
distinct parts: (1) a gas generator; (2) a mixing chamber into which
the gases and air are drawn by the natural draught, and wherein the
combustion of the gases begins; and (3) a furnace, or laboratory (not
represented in the figure), wherein the combustion is nearly finished,
and wherein take place the different reactions of puddling. These three
parts are given dimensions that vary according to the composition of the
different coals, and they may be made to use any sort of coal, even
the fine and schistose kinds which would not be suitable for ordinary
puddling. The gases and the air necessary for the combustion of these
being brought together at different temperatures, and being drawn into
the mixing chamber through the same chimney, it will be seen that the
dimensions of the flues that conduct them should vary with the kind of
coal used; and the manner in which the gases are brought together is not
a matter of indifference.

[Illustration: THE BICHEROUX SYSTEM OF FURNACE.

Vertical Section, and Horizontal Section through MNOPQR]

The gas generator consists of a hopper, A, into which drops, through
small apertures a, the coal piled up on the platform, D. These apertures
are closed with coal or bricks. The bottom of the generator is formed of
a small standing grate. The coal, on falling upon a mass in a state of
ignition, distills and becomes transformed into coke, which gradually
slides down over a grate to produce afterward, through its own
combustion, a distillation of the coal following it. But as these are
features found in all generators we will not dwell upon them.

The gases that are produced flow through a long horizontal flue, B, into
a vertical conduit, E, into which there debouches at the upper part a
series of small orifices, F, that conduct the air that has been heated.
The gases are inflamed, and traverse the furnace c (not shown in the
cut), from whence they go to the chimney. Before the air is allowed to
reach the intervening chamber it is made to pass into the sole of the
furnace and into the walls of the chamber, so that to the advantage of
having the air heated there is joined the additional one of having those
portions of the furnace cooled that cannot be heated with impunity.

The incompletely burned gases that escape from the furnace are utilized
in heating the boilers of the establishment. The dimensions given these
furnaces vary greatly according to the charge to be used. All the
results at Ougrée have been obtained with 400 kilogramme charges,
and the dimensions of the gas generators have been calculated for
Six-Bonniers coal, which does not yield over 20 per cent. of gas.

The advantages of this system, which permits of expediting all the
operations of puddling, are as follows:

1. A notable economy in fuel, both as regards quantity and quality.

2. Economy resulting from diminution in the waste of metal, with a
consequent improvement in the quality of the products obtained.

3. Diminution in cost of repairs.

4. Less rapid wear in the grates.

5. Improvement in the conditions of the work of puddling.

As regards the first of these advantages, it may be stated that the
puddling of ordinary Ougrée forge iron, which required with other
furnaces 900 to 1,000 kilogrammes of coal, is now performed with less
than 600 kilogrammes per ton of the iron produced. The puddling of fine
grained iron which required 1,300 to 1,500 kilogrammes of coal is now
done with 800. So much for quantity; as for quality the system presents
also a very marked advantage in that it requires no rolling coal--the
operation of the furnace being just as regular with fine coal, even that
sifted through screens of 0.02 meter.

The second class of advantages naturally results from the almost
complete prevention of access of cold air. The saving in wastage amounts
to 3 or 4 per cent., that is to say, 100 kilogrammes of iron produced is
accompanied by a loss of only 9 to 10 kilogrammes, instead of 13 to 15
as ordinarily reckoned.

The diminution in the cost of repairs is due to the fact that the
furnace doors, of which there are two, permit of easy access to all
parts of the sole; moreover, the coal never coming in contact with the
fire-bridges, the latter last much longer than those in other styles of
furnaces, and can be used for several weeks without the necessity of
the least repair. The reduced wear of the grates results from the low
temperature that can be used in the furnace, and the quantity of clinker
that can be left therein without interfering with its operation, thus
permitting of having the grates always black. These latter in no wise
change, and after five months of work the square bars still preserve
their sharpness of edges.

As for the improvements in the conditions of the work of puddling, it
may be stated that with a uniform price per 100 kilogrammes for all the
furnaces, the laborers working at the gas furnaces can earn 25 to 30 per
cent. more than those working at ordinary furnaces.

       *       *       *       *       *




GESSNER'S CONTINUOUS CLOTH-PRESSING MACHINE.


It is well known that there are several serious drawbacks in the usual
plan of pressing woolen or worsted cloths and felts with press plates,
press papers, and presses. Three objections of great weight may be
mentioned, and events in Leeds give emphasis to a fourth. The three
objections are--the labor required in setting or folding the cloth,
the expense of the press papers, and the time required. The fourth
objection, about which a dispute has occurred between the press-setters
and the master finishers in Leeds, refers to the inapplicability of the
common system to long lengths. The men object to these on account of
the great labor involved in shifting the heavy mass of cloth and press
plates to and from the presses. A minor drawback of this system is
that it involves the presence of a fold up the middle of the piece. On
account of these drawbacks it has long been understood to be desirable
to expedite the process, and also to dispense with the press papers.
This is the main purpose of the machine we now illustrate in section, in
which the pressing is done continuously by what may be termed a species
of ironing. The machine consists of a central hollow cylinder, C,
three-quarters of the circumference of which is covered by the hollow
boxes, M, heated by steam through the pipes shown, and which are
mounted upon the levers, BB', whose fulcra are at bb. By means of the
hand-wheel, T, and worm-wheel, n, which closes or opens the levers, BB',
the pressure of the boxes upon the central roller may be adjusted at
will, the spring-bolt, F, allowing a certain amount of yield. The faces
of the press-boxes, MM, are covered by a curved sheet of German silver
attached to the point, Y. This sheet takes the place of the press papers
in the ordinary process. The course of the cloth through the machine is
as follows, and is shown by the arrows: It is placed on the bottom board
in front, and in its travel it passes over the rails, O, after which it
is operated on by the brush, Z, leaving which it is conveyed over the
rails, V and I, the rollers, K and P, and thence between the pressing
roller, C, and the German silver press plate covering the heated boxes,
M. Leaving these the piece passes over the roller, P, and is cuttled
down in the bottom board by the cuttling motion, F, or a rolling-up
motion may be applied. The maker states that arrangements for brushing
and steaming may also be attached, so that in one passage through the
machine a piece may be pressed, brushed, and steamed. The speed of the
cylinder may be adjusted according to the quality or requirements of
the goods that are under treatment. At the time of our visit, says the
_Textile Manufacturer_, printed woolen pieces were being pressed at the
rate of about four yards a minute, but higher speeds are often obtained.
Messrs. Taylor, Wordsworth & Co., who have erected many of these
machines in Leeds, Bradford, and Batley, inform us that they find they
are adapted for the pressing of a wide variety of cloths, from Bradford
goods and thin serges to the heavy pieces of Dewsbury and Batley. The
inventor, Ernst Gessner, of Aue, Saxony, adopts an ingenious expedient
for pressing goods with thick lists. He provides an arrangement for
moving the cylinder endwise, according to the different widths of
the pieces to be treated. One list is left outside at the end of the
cylinder, and the other at the opposite end of the pressing boxes. The
machine we saw was 80 in. wide on the roller, and it was one the design
and construction of which undoubtedly do credit to Mr. Gessner.

[Illustration]

       *       *       *       *       *




IMPROVEMENTS IN WOOLEN CARDING ENGINES.


Mr. Bolette, who has made a name for himself in connection with strap
dividers, has experimented in another direction on the carding engine,
and as his ideas contain some points of novelty we herewith give the
necessary illustrations, so that our readers can judge for themselves as
to the merit of these inventions.

[Illustration: Fig. 1.]

Fig. 1 represents the feeding arrangement. Here the wool is delivered by
the feed rollers, A A, in the usual manner. The longer fibers are then
taken off by a comb, B, and brought forward to the stripper, E, which
transfers them to the roller, H, and thence to the cylinder. The shorter
fibers which are not seized by the comb fall down, but as they drop
they meet a blast of air created by a fan, which throws the lighter and
cleaner parts in a kind of spray upon the roller, L, whence they pass on
to the cylinder, while the dirt and other heavier parts fall downwards
into a box, and are by this means kept off the cylinder. It is evident
that in this arrangement it is not intended to keep the long and the
short fibers separate, but to utilize them all in the formation of
the yarn. The arrangement shown in Fig. 2 refers to the delivery end.
Instead of the sliver being wound upon the roller in the usual way, it
runs upon a sheet of linen, P¹, as in the case of carding for felt, with
a to-and-fro motion in the direction of the axis of the rollers. In this
way one or more layers of the fleece can be placed on the sheet, which
in that case passes backwards and forwards from roller S to R, and _vice
versa_. It is, in fact, the bat arrangement used for felt, only with
this difference, that the bat is at once rolled up instead of going
through the bat frame. In the manufacture of felt it is of course of
importance to have many very thin layers of fleece superposed over
each other in order to equalize it, and if the same is applied to the
manufacture of cloth it will no doubt give satisfactory results, but may
be rather costly.

[Illustration: Fig. 2.]

       *       *       *       *       *




NOVELTIES IN RING SPINDLES.


One of the drawbacks of ring spinning is the uneven pull of the
traveler, which is the more difficult to counteract as it is exerted
in jerks at irregular intervals. It is argued that with spindles and
bearings as usually made the spindle is supported firmly in its bearing,
and cannot give in case of such a lateral pull when exerted through the
yarn by the traveler, and the consequence is either a breakage of the
yarn or an uneven thread. Impressed with this idea, and in order to
remedy this defect, an eminent Swiss firm has hit upon the notion of
driving the spindle by friction, and to make it more or less loose in
the bearings, so that in case of an extra pull by the traveler the
spindle can give way a little, and thus prevent the breakage of the
yarn. This idea has been carried out in four different ways, and as this
seems to be an entirely new departure in ring spinning, we give the
illustrations of their construction in detail.

[Illustration: Fig. 1. Fig. 2. Fig. 3. Fig. 4.]

Fig. 1 represents Bourcart's recent arrangement of attaching the thread
guide to the spindle rail and the adjustable spindle. The spindle is
held by the sleeve, g, which latter is screwed into the spindle rail, S,
this being moved by the pinion, a; the collar is elongated upwards in a
cuplike form, c, the better to hold the oil, and keep it from flying;
d is the wharf, which has attached to it the sleeve, m, and which is
situated loosely in the space between the spindle and the footstep, e.
Above the wharf the spindle is hexagonal in shape, and to this part is
attached the friction plate, a. Between the latter and the upper surface
of the wharf a cloth or felt washer is inserted, to act as a brake. The
footstep, e, is filled with oil, in which run the foot of the spindle
and the sleeve m, the latter turning upon a steel ring situated on the
bottom of the footstep. As, thus, the foot of the spindle is quite free,
the upper part of the spindle can give sideways in the direction of any
sudden pull, and the foot of the spindle can follow this motion in the
opposite direction, the collar forming the fulcrum for the spindle. By
this alteration of the vertical position of the spindle into an inclined
one (though ever so trifling), the contact of the friction plate, a, and
the wharf is interrupted, and thus the speed of the spindle reduced.
This will cause less yarn to be wound on, and the pull thus to be
neutralized; but as the wharf keeps turning at the same speed, its
centrifugal force will act again upon the friction plate, and thus bring
the spindle back to its vertical position as soon as the extra drag has
been removed.

In Fig. 2 the footstep, e, has the foot of the spindle more closely
fitting at the bottom, but the upper part of the step opens out
gradually, and forms a conical cavity of a little larger diameter than
the spindle, so that the latter has a considerable play sideways. The
wharf carries in its lower part the sleeve, g, which runs upon a steel
ring as above. The upper surface of the wharf is arched, and upon this
is fitted the correspondingly arched friction plate, a, which latter
is attached to the spindle by a screw. The position of the spindle is
maintained by the collar, m. This collar is loose in the spindle rail,
and only held by the spring, m'. If now, a lateral drag is exerted upon
the upper part of the spindle, the collar car follows the direction of
this drag, and the spindle thus be brought out of the vertical position,
the friction plate slipping at the same time. The force of the spring
conjointly with the centrifugal force will then bring back the spindle
into its normal position as soon as the drag is again even.

Fig. 3 shows a spindle with a very long conical oil vessel, B, resting
upon a disk, e", in cup, e', with a cover, e"'. The wharf, d, is here
situated high up the spindle, has the same sleeve as in the preceding
case, and runs round the bush, g, upon the ring, z. The friction plate
resting upon the wharf is joined to the collar, a, running out into a
cup shape, which is fixed to the spindle, which here has a hexagonal
form. In this case the collar gives with the spindle, which latter
has the necessary play in the long footstep; and as the collar and
friction-plate are one, it is brought back to its normal place by
centrifugal force.

A peculiar arrangement is shown in Fig. 4. Here the ring and traveler,
f, are placed as usual, but the spindle carries at the same time an
inverted flier, t. The spindle turns loosely in the footstep, e, the
oil chamber being carried up to the middle of its height. The wharf
is placed in the same position as in the previous case, having also
a sleeve running in the oil chamber, c, upon a steel ring, z. The
friction-plate a, on the top of the wharf carries the flier, and on its
upper surface is in contact with the inverted cup, a, which is attached
to the spindle by a pin or screw. In order to limit at will the lateral
motion of the spindle there is attached to the latter, between the
footstep and the collar, a split ring, i, which can be closed more
or less by a small set screw. The spindle is thus only held in the
perpendicular position by its own velocity, which will facilitate a
high degree of speed, through the entire absence of all friction in the
bearings, this vertical position being assisted by the friction motion
whenever the spindle has been drawn on one side. Although the notion of
mounting spindles so that they can yield in order to center themselves
is not new, it is evident that considerable ingenuity has been brought
to bear upon the arrangement of the spindles we have described, but we
are not in a position to say to what extent practice has in this case
coincided with theory.--_Textile Manufacturer_.

       *       *       *       *       *




PHOTO-ENGRAVING ON ZINC OR COPPER.

By LEON VIDAL.


This process is similar in many respects to the one which was some
time ago communicated to the Photographic Society of France by M.
Stronbinsky, of St. Petersburg, but in a much improved and complete
form. An account of it was given by M. Gobert, at the meeting of the
same society, on the 2d December, 1882. The following are the details,
as demonstrated by me at the meeting of the 9th of May last:

Sheets of zinc or of copper of a convenient size are carefully planished
and polished with powdered pumice stone. The sensitive mixture is
composed of:

  The whites of four fresh eggs beaten
  to a froth......................... 100    parts
  Pure bichromate of ammonia.........   2.50   "
  Water..............................  50      "

After this mixture has been carefully filtered through a paper filter, a
few drops of ammonia are added. It will keep good for some time if well
corked and preserved from exposure to the light. Even two months after
being prepared I have found it to be still good; but too large a
quantity should not be prepared at a time, as it does not improve with
keeping.

I find that the dry albumen of commerce will answer as well as the
fresh. In that case I employ the following formula:

  Dry albumen from eggs.............. 15 to 20    parts
  Water..............................      100      "
  Ammonia bichromate.................        2.50   "

Always add some drops of ammonia, and keep this mixture in a well corked
bottle and in a dark place.

To coat the metal plate, place it on a turning table, to which it is
made fast at the center by a pneumatic holder; to assure the perfect
adhesion of this holder, it is as well to wet the circular elastic ring
of the holder before applying it to the metallic surface. When this is
done, the table may be made to rotate quickly without fear of detaching
the plate by the rapidity of the movement. The plate is placed in a
perfectly horizontal position, where no dust can settle on it; the
mixture is then poured on it, and distributed by means of a triangular
piece of soft paper, so as to cover equally all the parts of the plate.
Care should be taken not to flow too much liquid over the plate, and
when the latter is everywhere coated, the excess is poured off into a
different vessel from that which contains the filtered mixture, or else
into a filter resting on that vessel. The turning table should now be
inverted so that the sensitive surface may be downwards, and it is made
to rotate at first slowly, afterwards more rapidly, so as to make the
film, which should be very thin, quite smooth and even. The whole
operation should be carried out in a subdued light, as too strong a
light would render insoluble the film of bichromated albumen.

When the film is equalized the plate must be detached from the turning
table and placed on a cast iron or tin plate heated to not more than 40°
or 50° C. A gentle heat is quite sufficient to dry the albumen quickly;
a greater heat would spoil it, as it would produce coagulation. So soon
as the film is dry, which will be seen by the iridescent aspect it
assumes, the plate is allowed to cool to the ordinary temperature,
and is then at once exposed either beneath a positive, or beneath an
original drawing the lines of which have been drawn in opaque ink, so as
to completely prevent the luminous rays from passing through them; the
light should only penetrate through the white or transparent ground of
the drawing.

I say a _positive_ because I wish to obtain an engraved plate; if I
wanted to have a plate for typographic printing, I should have to take a
_negative_. After exposure the plate must be at once developed, which is
effected by dissolving in water those parts of the bichromated gelatine
which have been protected from the action of light by the dark spaces
of the cliché; these parts remain soluble, while the others have been
rendered completely insoluble. If the plate were dipped in clear water
it would be difficult to observe the picture coming out, especially on
copper. To overcome this difficulty the water must be tinged with some
aniline color; aniline red or violet, which are soluble in water,
answers the purpose very well. Enough of the dye must be dissolved in
the water to give it a tolerably deep color. So soon as the plate is
plunged into this liquid the albumen not acted on by light is dissolved,
while the insoluble parts are colored by absorbing the dye, so that the
metal is exposed in the lines against a red or violet ground, according
to the color of the dye used.

When the drawing comes out quite perfect, and a complete copy of the
original, the plate with the image on it is allowed to dry either of its
own accord, or by submitting it to a gentle heat. So soon as it is dry
it is etched, and this is done by means of a solution of perchloride
of iron in alcohol. Both alcohol and iron perchloride will coagulate
albumen; their action, therefore, on the image will not be injurious,
since they will harden the remaining albumen still further. But to get
the full benefit of this, the alcohol and the iron perchloride must
both be free from water; it is therefore advisable to use the salt in
crystals which have been thoroughly dried, and the alcohol of a strength
of 95°.

The following is the formula:

  Perchloride of iron, well dried     50 gr.
  Alcohol at 95°                     100 "

This solution must be carefully filtered so as to get rid of any deposit
which may form, and must be preserved in a well-corked bottle, when it
will keep for a long time. The plate is first coated with a varnish of
bitumen of Judea on the edges (if those parts are not already covered
with albumen) and on the back, so that the etching liquid can only act
on the lines to be engraved. It is then placed, with the side to be
engraved downwards, in a porcelain basin, into which a sufficient
quantity of the solution of perchloride of iron is poured, and the
liquid is kept stirred so as to renew the portion which touches the
plate; but care must be taken not to touch with the brush the parts
where there is albumen remaining. The length of time that the etching
must be continued depends on the depth required to be given to
the engraving; generally a quarter of an hour will be found to be
sufficient. Should it be thought desirable to extend the action over
half an hour, the lines will be found to have been very deeply engraved.
When the etching is considered to have been pushed far enough, the plate
must be withdrawn from the solution, and washed in plenty of water;
it must then be forcibly rubbed with a cloth so as to remove all the
albumen, and after it has been polished with a little pumice, the
engraving is complete.

It will be seen that this process may be used with advantage instead of
that of photo-engraving with bitumen, in cases where it is not advisable
to use acids. One of my friends, Mr. Fisch, suggests the plan--which
seems to deserve a careful investigation--of combining this process
with that where bitumen is employed; it would be done somewhat in the
following way. The plate of metal would be first coated evenly with
bitumen of Judea on the turning table, and when the bitumen is quite
dry, it should be again coated with albumen in the manner as described
above. In full sunlight the exposure need not exceed a minute in length;
then the plate would be laid in colored water, dried, and immersed in
spirits of turpentine. The latter will dissolve the bitumen in all
the parts where it has been exposed by the removal of the albumen not
rendered insoluble by the action of light. But it remains to be seen
whether the albumen will not be undermined in this method; therefore,
before recommending the process, it ought to be thoroughly studied. The
metal is now exposed in all the parts that have to be etched, while
all the other parts are protected by a layer of bitumen coated with
coagulated albumen. Hence we may employ as mordant water acidulated with
3, 4, or 5 per cent. of nitric acid, according as it is required to have
the plate etched with greater or less vigor.

By following the directions above given, any one wishing to adopt the
process cannot fail of obtaining good results, One of its greatest
advantages is that it is within the reach of every one engaged in
printing operations.--_Photo News_.

       *       *       *       *       *




MERIDIAN LINE.

[Footnote: From Proceedings of the Association of County Surveyors of
Ohio, Columbus, January, 1882.]


The following process has been used by the undersigned for many years.
The true meridian can thus be found within one minute of arc:

_Directions_.--Nail a slat to the north side of an upper window--the
higher the better. Let it be 25 feet from the ground or more. Let it
project 3 feet. Kear the end suspend a plumb-bob, and have it swing in a
bucket of water. A lamp set in the window will render the upper part of
the string visible. Place a small table or stand about 20 feet south of
the plumb-bob, and on its south edge stick the small blade of a pocket
knife; place the eye close to the blade, and move the stand so as to
bring the blade, string, and polar star into line. Place the table so
that the star shall be seen very near the slat in the window. Let this
be done half an hour before the greatest elongation of the star. Within
four or five minutes after the first alignment the star will have moved
to the east or west of the string. Slip the table or the knife a little
to one side, and align carefully as before. After a few alignments the
star will move along the string--down, if the elongation is west; up, if
east. On the first of June the eastern elongation occurs about half-past
two in the morning, and as daylight comes on shortly after the
observation is completed, I prefer that time of year. The time of
meridian passage or of the elongation can be found in almost any work on
surveying. Of course the observer should choose a calm night.

In the morning the transit can be ranged with the knife blade and
string, and the proper angle turned off to the left, if the elongation
is east; to the right, if west.

Instead of turning off the angle, as above described, I measure 200 or
300 feet northtward, in the direction of the string, and compute the
offset in feet and inches, set a stake in the ground, and drive a tack
in the usual way.

Suppose the distance is 250 feet and the angle 1° 40', then the offset
will be 7,271 feet, or 7 feet 3¼ inches. A minute of arc at the distance
of 250 feet is seven-eighths of an inch; and this is the most accurate
way, for the vernier will not mark so small a space accurately.


ANGLE OF ELONGATION.

This should be computed by the surveyor for each observation. The
distance between the star and the pole is continually diminishing, and
on January 1, 1882, was 1° 18' 48".

There is a slight annual variation in the distance. July 1, 1882, it
will be 1° 19' 20". If from this latter quantity the observer will
subtract 16" for 1883, and the same quantity for each succeeding year
for the next four or five years, no error so great as one-quarter of a
minute will be made in the position of the meridian as determined in the
summer months. If winter observations are made, the distance in January
should be used. The formula for computing the angle of elongation is
easily made by any one understanding spherical trigonometry, and is
this:

   R x sin. Polar dist.
  --------------------- = sin. of angle of elongation.
        cos. lat.

As an example, suppose the time is July, 1882, and the latitude 40°.
Then the computation being made, the angle will be found to be 1° 43'
34". A difference of six minutes in the latitude will make less than
10" difference in the angle, as one can see by trial. Any good State
or county map will give the latitude to within one or two miles--or
minutes.

The facts being as here stated, the absurdity of the Ohio law,
concerning the establishment of county meridians, becomes apparent. The
longitude has nothing at all to do With the meridian; and a difference
of _six miles_ in latitude makes no appreciable error in the meridian
established as here suggested, whereas the statute requires the latitude
within _one half a second_, which is _fifty feet_. There are some other
things, besides the ways of Providence, which may be said to be "past
finding out." It is not probable that a surveyor would err so much as
_three_ miles in his latitude, but should he do so, then the error in
his meridian line, resulting from the mistake, will be _five seconds_,
and a line _one mile_ long, run on a course 5" out of the way, will vary
but _an inch and a half_ from the true position. Surveyors well know
that no such accuracy is attainable. R. W. McFARLAND,

       *       *       *       *       *




ELECTRO-MANIA.

By W. MATTIEU WILLIAMS.


A history of electricity, in order to be complete, must include two
distinct and very different subjects: the history of electrical science,
and a history of electrical exaggerations and delusions. The progress of
the first has been followed by a crop of the second from the time when
Kleist, Muschenbroek, and Cuneus endeavored to bottle the supposed
fluid, and in the course of these attempts stumbled upon the "Leyden
jar."

Dr. Lieberkuhn, of Berlin, describes the startling results which he
obtained, or imagined, "when a nail or a piece of brass wire is put into
a small apothecary's phial and electrified." He says that "if, while it
is electrifying, I put my finger or a piece of gold which I hold in my
hand to the nail, I receive a shock which stuns my arms and shoulders."
At about the same date (the middle of the last century), Muschenbroek
stated, in a letter to Réaumur, that, on taking a shock from a thin
glass bowl, "he felt himself struck in his arms, shoulders, and breast,
so that he lost his breath, and was two days before he recovered from
the effects of the blow and the terror" and that he "would not take a
second shock for the kingdom of France." From the description Of the
apparatus, it is evident that this dreadful shock was no stronger than
many of us have taken scores of times for fun, and have given to
our school-follows when we became the proud possessors of our first
electrical machine.

Conjurers, mountebanks, itinerant quacks, and other adventurers operated
throughout Europe, and were found at every country fair and _fete_
displaying the wonders of the invisible agent by giving shocks and
professing to cure all imaginable ailments.

Then came the discoveries of Galvani and Volta, followed by the
demonstrations of Galvani's nephew Aldini, whereby dead animals were
made to display the movements of life, not only by the electricity of
the Voltaic pile, but, as Aldini especially showed, by a transfer of
this mysterious agency from one animal to another.

According to his experiments (that seem to be forgotten by modern
electricians) the galvanometer of the period, a prepared frog, could be
made to kick by connecting its nerve and muscle with muscle and nerve of
a recently killed ox, with, or without metallic intervention.

Thus arose the dogma which still survives in the advertisements of
electrical quacks, that "electricity is life," and the possibility of
reviving the dead was believed by many. Executed criminals were in
active demand; their bodies were expeditiously transferred from the
gallows or scaffold to the operating table, and their dead limbs were
made to struggle and plunge, their eyeballs to roll, and their features
to perpetrate the most horrible contortions by connecting nerves with
one pole, and muscles with the opposite pole of a battery.

The heart was made to beat, and many men of eminence supposed that if
this could be combined with artificial respiration, and kept up for
awhile, the victim of the hangman might be restored, provided the neck
was not broken. Curious tales were loudly whispered concerning gentle
hangings and strange doings at Dr. Brookes's, in Leicester Square, and
at the Hunterian Museum, in Windmill Street, now flourishing as "The
Café de l'Etoile." When a child, I lived about midway between these
celebrated schools of practical anatomy, and well remember the tales of
horror that were recounted concerning them. When Bishop and Williams (no
relation to the writer) were hanged for burking, i.e., murdering people
in order to provide "subjects" for dissection, their bodies were sent to
Windmill Street, and the popular notion was that, being old and faithful
servants of the doctors, they were galvanized to life, and again set up
in their old business.

It is amusing to read some of the treatises on medical galvanism that
were published at about this period, and contrast their positive
statements of cures effected and results anticipated with the position
now attained by electricity as a curative agent.

Then came the brilliant discoveries of Faraday, Ampère, etc.,
demonstrating the relations between electricity and magnetism, and
immediately following them a multitude of patents for electro-motors,
and wild dreams of superseding steam-engines by magneto-electric
machinery.

The following, which I copy from the _Penny Mechanic_, of June 10, 1837,
is curious, and very instructive to those who think of investing in any
of the electric power companies of to-day: "Mr. Thomas Davenport, a
Vermont blacksmith, has discovered a mode of applying magnetic and
electro-magnetic power, which we have good ground for believing will be
of immense importance to the world." This announcement is followed by
reference to Professor Silliman's _American Journal of Science and the
Arts_, for April, 1837, and extracts from American papers, of which the
following is a specimen: "1. We saw a small cylindrical battery, about
nine inches in length, three or four in diameter, produce a magnetic
power of about 300 lb., and which, therefore, we could not move with
our utmost strength. 2. We saw a small wheel, five-and-a-half inches in
diameter, performing more than 600 revolutions in a minute, and lift a
weight of 24 lb. one foot per minute, from the power of a battery of
still smaller dimensions. 3. We saw a model of a locomotive engine
traveling on a circular railroad with immense velocity, and rapidly
ascending an inclined plane of far greater elevation than any hitherto
ascended by steam-power. And these and various other experiments which
we saw, convinced us of the truth of the opinion expressed by Professors
Silliman, Renwick, and others, that the power of machinery may be
increased from this source beyond any assignable limit. It is computed
by these learned men that a circular galvanic battery about three feet
in diameter, with magnets of a proportionable surface, would produce at
least a hundred horse-power; and therefore that two such batteries would
be sufficient to propel ships of the largest class across the Atlantic.
The only materials required to generate and continue this power for
such a voyage would be a few thin sheets of copper and zinc, and a few
gallons of mineral water."

The Faure accumulator is but a very weak affair compared with this, Sir
William Thomson notwithstanding. To render the date of the above fully
appreciable, I may note that three months later the magazine from which
it is quoted was illustrated with a picture of the London and Birmingham
Railway Station displaying a first-class passenger with a box seat on
the roof of the carriage, and followed by an account of the trip to
Boxmoor, the first installment of the London and North-Western Railway.
It tells us that, "the time of starting having arrived, the doors of
the carriages are closed, and, by the assistance of the conductors, the
train is moved on a short distance toward the first bridge, where it
is met by an engine, which conducts it up the inclined plane as far as
Chalk Farm. Between the canal and this spot stands the station-house for
the engines; here, also, are fixed the engines which are to be employed
in drawing the carriages up the inclined plane from Euston Square, by
a rope upwards of a mile in length, the cost of which was upwards of
£400." After describing the next change of engines, in the same matter
of course way as the changing of stage-coach horses, the narrative
proceeds to say that "entering the tunnel from broad daylight to perfect
darkness has an exceedingly novel effect."

I make these parallel quotations for the benefit of those who imagine
that electricity is making such vastly greater strides than other
sources of power. I well remember making this journey to Boxmoor, and
four or five years later traveling on a circular electro-magnetic
railway. Comparing that electric railway with those now exhibiting,
and comparing the Boxmoor trip with the present work of the London and
North-Western Railway, I have no hesitation in affirming that the rate
of progress in electro-locomotion during the last forty years has been
far smaller than that of steam.

The leading fallacy which is urging the electro-maniacs of the present
time to their ruinous investments is the idea that electro-motors
are novelties, and that electric-lighting is in its infancy; while
gas-lighting is regarded as an old, or mature middle-aged business,
and therefore we are to expect a marvelous growth of the infant and no
further progress of the adult.

These excited speculators do not appear to be aware of the fact that
electric-lighting is older than gas-lighting; that Sir Humphry Davy
exhibited the electric light in Albemarle Street, while London was still
dimly lighted by oil-lamps, and long before gas-lighting was attempted
anywhere. The lamp used by Sir Humphry Davy at the Royal Institution, at
the beginning of the present century, was an arrangement of two
carbon pencils, between which was formed the "electric arc" by the
intensely-vivid incandescence and combustion of the particles of carbon
passing between the solid carbon electrodes. The light exhibited by Davy
was incomparably more brilliant than anything that has been lately shown
either in London, or Paris, or at Sydenham. His arc was _four inches
in length_, the carbon pencils were four inches apart, and a broad,
dazzling arch of light bridged the whole space between. The modern arc
lights are but pygmies, mere specks, compared with this; a leap of 1/3
or 1/4 inch constituting their maximum achievement.

Comparing the actual progress of gas and electric lighting, the gas has
achieved by far the greater strides; and this is the case even when we
compare very recent progress.

The improvements connected with gas-making have been steadily
progressive; scarcely a year has passed from the date of Murdoch's
efforts to the present time, without some or many decided steps having
been made. The progress of electric-lighting has been a series of
spasmodic leaps, backward as well as forward.

As an example of stepping backward, I may refer to what the newspapers
have described as the "discoveries" of Mr. Edison, or the use of an
incandescent wire, or stick, or sheet of platinum, or platino-iridium;
or a thread of carbon, of which the "Swan" and other modern lights are
rival modifications.

As far back as 1846 I was engaged in making apparatus and experiments
for the purpose of turning to practical account "King's patent electric
light," the actual inventor of which was a young American, named Starr,
who died in 1847, when about 25 years of age, a victim of overwork
and disappointment in his efforts to perfect this invention and a
magneto-electric machine, intended to supply the power in accordance
with some of the "latest improvements" of 1881 and 1882.

I had a share in this venture, and was very enthusiastic until after I
had become practically acquainted with the subject. We had no difficulty
in obtaining a splendid and perfectly steady light, better than any that
are shown at the Crystal Palace.

We used platinum, and alloys of platinum and iridium, abandoned them as
Edison did more than thirty years later, and then tried a multitude of
forms of carbon, including that which constitutes the last "discovery"
of Mr. Edison, viz., burnt cane. Starr tried this on theoretical
grounds, because cane being coated with silica, he predicted that by
charring it we should obtain a more compact stick or thread, as the
fusion of the silica would hold the carbon particles together. He
finally abandoned this and all the rest in favor of the hard deposit of
carbon which lines the inside of gas-retorts, some specimens of which we
found to be so hard that we required a lapidary's wheel to cut them into
the thin sticks.

Our final wick was a piece of this of square section, and about 1/8 of
an inch across each way. It was mounted between two forceps--one holding
each end, and thus leaving a clear half-inch between. The forceps were
soldered to platinum wires, one of which passed upward through the top
of the barometer tube, expanded into a lamp glass at its upper part.
This wire was sealed to the glass as it passed through. The lower wire
passed down the middle of the tube.

The tube was filled with mercury and inverted over a cup of mercury.
Being 30 inches long up to the bottom of the expanded portion, or lamp
globe, the mercury fell below this and left a Torricellian vacuum there.
One pole of the battery, or dynamo-machine, was connected with the
mercury in the cup, and the other with the upper wire. The stick of
carbon glowed brilliantly, and with perfect steadiness.

I subsequently exhibited this apparatus in the Town-hall of Birmingham,
and many times at the Midland Institute. The only scientific difficulty
connected with this arrangement was that due to a slight volatilization
of the carbon, and its deposition as a brown film upon the lamp glass;
but this difficulty is not insuperable.--_Knowledge_.

       *       *       *       *       *




ACTION OF MAGNETS UPON THE VOLTAIC ARC.


The action of magnets upon the voltaic arc has been known for a long
time past. Davy even succeeded in influencing the latter powerfully
enough in this way to divide it, and since his time Messrs. Grove and
Quet have studied the effect under different conditions. In 1859, I
myself undertook numerous researches on this subject, and experimented
on the induction spark of the Ruhmkorff coil, the results of these
researches having been published in the last two editions of my notes on
the Ruhmkorff apparatus.

[Illustration: FIG. 1]

These researches were summed up in the journal _La Lumière Electrique_
for June 15, 1879. Recently, Mr. Pilleux has addressed to us some new
experiments on the same subject, made on the voltaic arc produced by a
De Meritens alternating current machine. Naturally, he has found the
same phenomena that I had made known; but he thinks that these new
researches are worthy of interest by reason of the nature of the arc in
which he experimented, and which, according to him, is of a different
nature from all those on which, up to the present time, experiments have
been made. Such a distinction as this, however, merits a discussion.

With the induction spark, magnets have an action only on the aureola
which accompanies the line of fire of the static discharge; and this
aureola, being only a sort of sheath of heated air containing many
particles of metal derived from the rheophores, represents exactly the
voltaic arc.

[Illustration: FIG. 2]

Moreover, although the induced currents developed in the bobbin are
alternately of opposite direction, the galvanometer shows that the
currents that traverse the break are of the same direction, and that
these are direct ones. The reversed currents are, then, arrested during
their passage; and, in order to collect them, it becomes necessary to
considerably diminish the gaseous pressure of the aeriform conductor
interposed in the discharge; to increase its conductivity; or to open to
the current a very resistant metallic derivation. By this latter means,
I have succeeded in isolating, one from the other, in two different
circuits, the direct induced currents and the reversed induced ones.
As only direct currents can, in air at a normal pressure, traverse
the break through which the induction spark passes, the aureola that
surrounds it may be considered as being exactly in the same conditions
as a voltaic arc, and, consequently, as representing an extensible
conductor traversed by a current flowing in a definite direction. Such
a conductor is consequently susceptible of being influenced by all the
external reactions that can be exerted upon a current; only, by reason
of its mobility, the conductor may possibly give way to the action
exerted upon the current traversing it, and undergo deformations that
are in relation with the laws of Ampère. It is in this manner that I
have explained the different forms that the aureola of the induction
spark assumes when it is submitted to the action of a magnet in the
direction of its axial line, or in that of its equatorial line, or
perpendicular to these latter, or upon the magnetic poles themselves.

Experiments of a very definite kind have not yet been made as to the
nature of the arc produced by induced currents developed in alternating
current machines; but, from the experiments made with electric candles,
we are forced to admit that the current reacts as if it were alternately
reversed through the arc, since the carbons are used up to an equal
degree; and, moreover, Mr. Pilleux's experiments show that effects
analogous to those of induction coils are produced by the reaction of
magnets upon the arc. There is, then, here a doubtful point that it
would be interesting to clear up; and we believe that it is consequently
proper to introduce in this place Mr. Pilleux's note:

"Having at my disposal," says he, "a powerful vertical voltaic arc of 12
centimeters in length, kept up by alternately reversed currents, and one
of the most powerful permanent magnets that Mr. De Meritens employs for
magneto-electric machines, I have been enabled to make the following
experiments:

"1. When I caused one of the poles of my magnet to slowly approach the
voltaic arc, I ascertained that, at a distance of 10 centimeters, the
arc became flattened so as to assume the appearance of those gas jets
called 'butterfly.' The plane of the 'butterfly' was parallel with the
pole that I presented, or, in other words, with the section of the
magnet. At the same time, the arc began to emit a strident noise, which
became deafening when the pole of the magnet was brought to within a
distance of about 2 millimeters. At this moment, the butterfly form
produced by the arc was _greatly spread out, and reduced to the
thickness of a sheet of paper_; and then it burst with violence, and
projected to a distance a great number of particles of incandescent
carbon.

"2. The magnet employed being a horseshoe one, when I directed it
laterally so as to present successively, now the north and then the
south pole to the arc, the 'butterfly' pivoted upon itself so as not to
present the same surface to each pole of the magnet."

By referring to the accompanying figure, which we extract from our note
on the Ruhmkorff apparatus, it will be seen that the aureola which
developed as a circular film from right to left at D, on the north pole
of the magnet, N.S. (Fig. 1), projected itself in an opposite direction
at C, upon the south pole, S, of the same magnet; but, between the two
poles, these two contrary actions being obliged to unite, they gave rise
in doing so to a very characteristic helicoid spiral whose direction
depended upon that of the current of discharge through the aureola,
or upon the polarity of the magnetic poles. On the contrary, when the
discharge took place in the direction of the equatorial line, as in Fig.
2, the circular film developed itself in the plane of the neutral line
above or below the line of discharge, according to the direction of the
current and the magnetic polarity of the magnet.

There is, then, between Mr. Pilleux's experiments and my own so great an
analogy that we might draw the deduction therefrom that induced currents
in alternating machines have, like those of the Ruhmkorff coil, a
definite direction, which would be that of currents having the greatest
tension, that is to say, that of direct currents. This hypothesis seems
to us the more plausible in that Mr. J. Van Malderem has demonstrated
that the attraction of solenoids with the currents, not straight,
of magneto-electric machines is almost as great as that of the same
solenoids with straight currents; and it is very likely that the
difference which may then exist should be so much the less in proportion
as the induced currents have more tension. We might, then, perhaps
explain the different effects of the wear of the carbons serving as
rheophores, according as the currents are continuous or alternating, by
the different calorific effects produced on these carbons, and by the
effects of electric conveyance which are a consequence of the passage of
the current through the arc.

We know that with continuous currents the positive carbon possesses a
much higher temperature than the negative, and that its wear is about
twice greater than that of the latter. But such greater wear of the
positive carbon is especially due to the fact that combustion is greater
on it than on the negative, and also to the fact that the carbonaceous
particles carried along by the current to the positive pole are
deposited in part upon the other pole. Supposing that these polarities
of the carbons were being constantly alternately reversed, the effects
might be symmetrical from all quarters, although the only current
traversing the break were of the same direction; for, admitting that the
reverse currents could not traverse the break, they would exist none the
less for all that, and they might give rise (as has been demonstrated
by Mr. Gaugain with regard to the discharges of the induction spark
intercepted by the insulating plate of a condenser) to return discharges
through the generator, which would then have, in the metallic part of
the circuit, the same direction as the direct currents succeeding,
although they had momentarily brought about opposite polarities in the
electrodes. What might make us suppose such an interpretation of the
phenomenon to have its _raison d'etre_, is that with the induced
currents of the Ruhmkorff coil, it is not the positive pole that is
the hottest, but rather the negative; from whence we might draw the
deduction that it is not so much the direction of the current that
determines the calorific effect in the electrodes, as the conditions of
such current with respect to the generator. I should not be
surprised, then, if, in the arc formed by the alternating currents of
magneto-electric machines, there should pass only one current of the
same direction, and which would be the one formed by the superposition
of direct currents, and if the reverse currents should cause return
discharges in the midst of the generating bobbins at the moment the
direct currents were generated.--_Th. Du Moncel_.

       *       *       *       *       *




VOLCKMAR'S SECONDARY BATTERIES.


The inventive genius of the country is now directed to these important
accessories of electric enterprise, and no wonder, for as far as can at
present be seen, the secret of electric motion lies in these secondary
batteries. Among other contributions of this kind is the following, by
Ernest Volckmar, electrician, Paris:

The object of this invention is to render unnecessary the use in
secondary batteries of a porous pot which creates useless resistance
to the electric current, and to store in an apparatus of comparatively
small weight and bulk considerable electric force. To this end two
reticulated or perforated plates of lead of similar proportions are
prepared, and their interstices are filled with granules or filaments of
lead, by preference chemically pure. These plates are then submitted to
pressure, and placed together, with strips of nonconducting material
interposed between them, in a suitable vessel containing a bath of
acidulated water. The plates being connected with wires from an electric
generator are brought for a while under the action of the current, to
peroxidize and reduce the whole of the finely divided lead exposed to
the acidulated water. The secondary battery is then complete. It will be
understood that any number of these pairs of plates may be combined to
form a secondary battery, their number being determined by the amount
of storage required. The perforated plates of lead may be prepared by
drilling, casting, or in other convenient manner, but the apertures, of
whatever form, should be placed as closely together as possible, and
the finely divided lead to be peroxidized is pressed into the cells or
cavities so as to fill their interiors only.

       *       *       *       *       *




THE MINERALOGICAL LOCALITIES IN AND AROUND NEW YORK CITY, AND THE
MINERALS OCCURRING THEREIN.

By NELSON H. DARTON.


There will be many persons in the city of New York and its suburbs who
will not have the time or facilities for leaving town during the summer,
to spend a part of their time enjoying the country, but would have
sufficient time to take occasional recreation for short periods. I have
sought by this paper to show a pleasurable, and at the same time very
instructive use for the time of this latter class, and that is in
mineralogy. In the surrounding parts of New York are many mineralogical
localities, known to no others than a few professional mineralogists,
etc., and from which an excellent assortment of minerals may be
obtained, which would well grace a cabinet and afford considerable
instruction and entertainment to their owner and friends, besides acting
as an incentive to a further study of this and the other sciences. These
localities which I will discuss are all within an hour's ride from New
York, and the expenses inside of a half dollar, and generally very much
less. I could detail many other places further off, but will reserve
that for another paper.

The course which I will pursue in my explanations I have purposely made
very simple, avoiding--or when using, explaining--all technical terms.
The apparatus and tests noticed are of the most rudimentary style
consistent with that which is necessary to attain the simple purpose of
distinguishment, and altogether I have prepared this paper for those
having at the present time little or no knowledge or practice in
mineralogy, while those having it can be led perhaps by the details of
the localities noticed. Another reason why I have written so in detail
of this last subject is, because the experiences of most amateur
mineralogists are generally so very discouraging in their endeavors to
find the minerals, and there is everything in giving a good start
to properly fix the interest on the subject. The reason of these
discouragements is simple, and generally because they do not know the
portion of the locality, say, for instance, a certain township, in which
the minerals occur. And if they do succeed in finding this, it is seldom
that the portion in which the mineral occurs, which is generally some
small inconspicuous vein or fissure, is found; and even in this it
is generally difficult to recognize and isolate the mineral from the
extraneous matter holding it. As an instance of this I might cite thus:
Dana, in his text book on mineralogy, will mention the locality for
a certain species, as Bergen Hill--say for this instance, dogtooth
calespar. When we consider that Bergen Hill, in the limited sense of the
expression, is ten miles long and fully one mile wide, and as the rock
outcrops nearly all over it, and it is also covered with quarries,
cuttings, etc., it may be seen that this direction is rather indefinite.
To the professional mineralogist it is but an index, however, and he
may consult the authority it is quoted from--the _American Journal of
Science_, etc.--and thus find the part referred to, or by consulting
other mineralogists who happen to know. Again, the person having found
by inquiry that the part referred to is the Pennsylvania Railroad, and
as this is fully a mile long and interspersed with various prominent
looking, but veins of a mineral of little value, at any rate not the one
in question, they are few who could suppose that it occurred in that.
Apparently a vein of it would not be noticed at all from the surrounding
rock of gravelly earth, but there it is, and in a vein of chlorite. This
is so throughout the long and more or less complete stated lists of
mineralogical localities. Thus I will, in describing the mineral, after
explaining the conditions under which it occurs, give almost the
exact spot where I have found the same mineral myself, and have left
sufficiently fine specimens to carry away, and thus no time will be lost
in going over fruitless ground, and further, this paper is written up to
the date given at its end, insuring a necessary presence of them.

In order that one not familiar with mineral specimens should not carry
off from the various localities a variety of worthless stones, etc.,
which are frequently more or less attractive to an inexperienced eye,
the following hints may be salutary.

There are the varieties of three minerals, which are very commonly met
with in greater or less abundance in mineralogical trips: they are of
calcite, steatite, and quartz. They occur in so many modifications of
form, color, and condition that one might speedily form a cabinet of
these, if they were taken when met with, and imagine it to be of great
value. The first of these is calcite. It occurs as marble, limestone;
calcspar, dogtooth spar, nail head spar, stalactites, and a number of
other forms, which are only valuable when occurring in perfect crystals
or uniquely set upon the rock holding it. The calcspar is extremely
abundant at Bergen Hill, where it might be mistaken for many of the
other minerals which I describe as occurring there, and even in
preference to them, to one's great chagrin upon arriving home and
testing it, to find that it is nothing but calcite. In order to avoid
this and distinguish this mineral on the field, it should be tested with
a single drop of acid, which on coming in contact with it bubbles up or
effervesces like soda water, seidlitz powder, etc., while it does not do
so with any of the minerals occurring in the same locality. This acid
is prepared for use as follows: about twenty drops of muriatic acid are
procured from a druggist in a half-ounce bottle, which is then filled up
with water and kept tightly corked. It is applied by taking a drop out
on a wisp of broom or a small minim dropper, which may be obtained at
the druggist's also. I do not say that in every case this mineral should
be rejected, because it is frequently very beautiful and worthy of place
in a cabinet, but should be kept only under the conditions mentioned
further on in this paper, under the head of "Calcite in Weehawken
Tunnel."

The next mineral abundant in so many forms is quartz, and is not so
readily distinguished as calcite. It is found of every color, shape,
etc., possible, and that which is found in any of the localities I am
about to describe, with the exception of fine crystals on Staten Island,
are of no value and may be rejected, unless answering in detail to the
description given under Staten Island. The method of distinguishing the
quartz is by its hardness, which is generally so great that it cannot be
scratched by the point of a knife, or at least with great difficulty,
and a fragment of it will scratch glass readily; thus it is
distinguished from the other minerals occurring in the localities
discussed in this paper.

The other minerals so common are the varieties of steatite. This is
especially so at Bergen Hill and Staten Island. They occur in amorphous
masses generally, and may be distinguished by being so soft as to be
readily cut by the finger nail. I will detail further upon the soapstone
forms in discussing the localities on Staten Island, and the chloritic
form under the head of "Weehawken Tunnel." The surest method of avoiding
these and recognizing the others by their appearance, which is generally
the only guide used by a professional mineralogist, is to copy off the
lists of the various minerals I describe, and, by visiting the American
Museum of Natural History on any week day except Mondays and Tuesdays,
one may see and become familiar with the minerals they are going
in quest of, besides others in the cases. This method is much more
satisfactory than printed descriptions, and saves the labor of many of
the distinguishing manipulations I am about to describe, besides saving
the trouble of bringing inferior specimens of the minerals home.

In going forth on a trip one should be provided with a mineralogical
hammer, or one answering its purpose, and a cold chisel with which to
detach or trim the minerals from adhering rocks, the bottle of acid
before referred to, and a three cornered file for testing hardness,
as explained further on. As I noticed before, the better plan of
distinguishing a mineral is by being familiar with its appearance, but
as this is generally impracticable, I will detail the modes used in
lieu of this to be applied on bringing the minerals home. These
distinguishments depend on difference in specific gravity, hardness,
solubility in hot acids, and the action of high heat. I will explain the
application of each one separately, commencing with--

_The Specific Gravity_.--In ascertaining the specific gravity the
following apparatus is necessary: a small pair of hand scales with a set
of weights, from one grain to one ounce. These can be procured from the
apparatus maker, the scales for about fifty cents, and the weights for
not much over the same amount. The scales are prepared for this work by
cutting two small holes in one of the scale pans, near together, with
a pointed piece of metal, and tying a piece of silk thread about eight
inches long into these. In a loop at the end of this thread the mineral
to be examined is suspended. It should be a pure representative of the
mineral it is taken from, should weigh about from one hundred grains to
an ounce, and be quite dry and free from dirt. If the piece of mineral
obtained is very large, this sized portion may be often taken from it
without injury; but it will not do to mar the beauty of a mineral to
ascertain its specific gravity, and it is generally only applicable
when a small piece is at hand. With more weights, however, a piece of a
quarter pound weight may be taken if necessary. The mineral is tied into
the loop and weighed, the weight being set down in the note book, either
in grains or decimal parts of an ounce. Call this result A. It is then
weighed in some water held in a vessel containing about a quart, taking
care while weighing it that it is entirely immersed, but at the same
time does not touch either the sides or bottom. Both weighings should
be accurate to a grain. This result we call B. The specific gravity is
found by subtracting B from A, and dividing A by the remainder. For
instance, if the mineral weighed eight hundred grains when weighed in
the air, and in the water six hundred, giving us the equation: 800
/ (800 - 600) = sp. gr., or 4, which is the specific gravity of
the mineral. If the mineral whose specific gravity is sought is an
incrustation on a rock, or a mixture of a number of minerals, or would
break to pieces in the water, the specific gravity is by this method of
course unattainable, and other data must be used.

_The Comparative Hardness_.--The next characteristic of the mineral to
be ascertained is the comparative hardness. In mineralogy there is a
scale fixed for comparison, from 1 to 10, 10 being the hardest, the
diamond, and Number 1 the soft soapstone. These and the intermediate
minerals fixed upon the scale are generally inaccessible to those who
may use the contents of this paper, and I will give some more familiar
materials for comparison. 8, 9, and 10 are the topaz, sapphire, and
diamond respectively, and as these and minerals of similar hardness will
probably not be found in any of the localities of which I make mention,
we need not become accustomed to them for the present. 7 is of
sufficient hardness to scratch glass, and is also not to be cut with the
file before mentioned, which is used for these determinations. 6 is
of the hardness of ordinary French glass. 5 is about the hardness of
horse-shoe or similar iron; 4 of the brown stone (sandstone) of which
the fronts of many city buildings, etc., are built; 3 of marble; 2 of
alabaster; and 1 as French chalk, or so soft as to be readily cut with
the finger nail. The method of using and applying these comparisons is
by having the above matters at hand, and compare them by the relative
ease with which they can be cut by running the edge of the file over
their surface. One will soon become familiar with the scale, and it
may of course then be discarded. As it is one of the most important
characteristics of some of the minerals, it should be carefully
executed, and the result carefully considered. It is of course
inapplicable under those conditions with minerals that are in very small
crystals or in a fibrous condition.

_Action of Hot Acids_.--This very important test is never, like the
above, applicable upon the field, but applied when home is reached.
From the body of the mineral as pure and clean as possible a portion is
chipped, about the size of a small pea; this is wrapped in a piece of
stiff wrapping paper, and after placing it in contact with a solid body,
crushed finally by a blow from the hammer. A pinch of the powder so
obtained is taken up on the point of a penknife, and transferred into
a test tube. Two or more of these should be provided, about six inches
long. They may be obtained in the apparatus shop for a trifle. Some
hydrochloric, or, as it is generally called, muriatic acid, is poured
upon it to the depth of about three quarters of an inch; the tube is
then placed in some boiling water heated over a lamp in a tinned or
other vessel, and allowed to boil for from ten to fifteen minutes;
the tube is then removed and its contents allowed to cool, and then
examined. If the powder has all disappeared, we term the mineral
"soluble;" if more or less is dissolved, "partly soluble;" if none,
"insoluble;" and if the contents of the tube are of a solid transparent
mass like jelly, "gelatinous;" while if transparent gelatinous flakes
are left, it is so termed. As this method of distinguishment is always
applicable, it is very important, and its detail and result should be
carefully noticed. Care should be taken that only a small portion of
the mineral is used, and also but little acid; the action should be
observed, and is frequently a characteristic, in the case with calcspar,
which effervesces while dissolving. The acid used is hydrochloric at
first, and then, if the mineral cannot he recognized, the same treatment
may be repeated using nitric acid. Both of these acids should be at hand
and two ounces are generally sufficient.

_Action of Heat_.--This is, perhaps, the most important characteristic,
and, when taken with the preceding data, will identify any of the
minerals found in any one locality, which I will describe, from each
other. The heat is applied to the mineral by means of a candle and
blowpipe. A thick wax candle answers well, and an ordinary japanned tin
blowpipe, costing twenty cents, will serve the purpose. The substance
to be examined is held on a loop of platinum wire about one inch to the
left and just below the top of the wick, which is bent toward it. Here
it is steadily held, as is shown in Fig. 1, and the flame of the candle
bent over upon it, and the heat intensified by blowing a steady and
strong current of air across it by means of the blowpipe held in the
mouth and supported by the right hand, whose elbow is resting upon the
table. The current of air is difficult to keep up by one unaccustomed to
the blowpipe, the skill of using which is readily obtained; it consists
in breathing through the nostrils, while the air is forced out by
pressure on the air held by the inflated cheeks, and not from the lungs.
This can be practiced while not using the blow-pipe, and may readily
be accomplished by one's keeping his cheeks distended with air and
breathing at the same time.

This heat is steadily applied until the splinter of mineral has been
kept at a high red heat for a sufficient length of time to convince one
of what it may do, as fuse or not, or on the edges. The first two
are evident, as when it fuses it runs into a globule; the last, by
inspecting it before and after the heating with a magnifying glass;
sometimes it froths up when heated, and is then said to "intumesce;" or,
if it flies to fragments, "decrepitates." Upon the first it is further
heated; but in the latter case, a new splinter of mineral must be broken
off from the mass and heated upon the wire very cautiously until quite
hot, when it may then be readily heated further without fear of loss.
For holding the splinter of mineral, which should well represent the
mass and be quite small, is a three-inch length of platinum wire of the
thickness of a cambric-needle; this may be bought for about ten cents at
the apparatus shop. The ends should be looped, as is shown in Fig. 2,
and the mineral placed in the loop.

Sometimes a mineral has to be fused with borax, as I mention further
on in my tables. This is done by heating the wire-loop to redness, and
plunging it into some borax; what adheres is fused upon it by heating.
Some more is accumulated in the same manner, until the loop is filled
with a fair-sized globule. A small quantity of the mineral, which had
been crushed as for the acid test, is caused to adhere to it while it is
molten, and then the heat of the blast directed upon it for some time
until either the small fragments of mineral dissolve, or positively
refuse to do so. After cooling, the aspect of the globule is noticed as
to color, transparency, etc. Care must be taken that too large an amount
of the mineral is not taken, a very minute amount being sufficient.

I trust by the use of these distinguishing reactions one will be able
to recognize by the tables to be given the name of the mineral in hand,
especially as they are from certain parts, where all the minerals
occurring therein are known to us; and I have worded the characteristics
so that they will serve to isolate from all that possibly could be found
in that locality.

The first general locality is Bergen Hill, New Jersey. This comprises
the range of bluffs of trap rock commencing at Bergen Point and running
up behind Jersey City and Hoboken, etc., to the part opposite about
Thirtieth Street, New York, where it comes close to the river, and from
there along the river to the north for a long distance, known as the
Palisades. It is about a mile wide on an average, and from a few feet to
about two hundred feet in height. The mineralogical localities in and
upon it are at the following parts, commencing at the south: First
Pennsylvania Railroad cuts where the mining operations are just about
completed; then the Erie Tunnel, in which the specimens that first made
Bergen Hill noted as a mineralogical locality, and whose equals have not
since been procured, were found, but which is now inaccessible to the
general public. Further north is the Morris and Essex Tunnel, in which
many fine specimens were secured, and is also inaccessible; and last,
but far from being least, is the Ontario Tunnel at Weehawken; and, as
it is the only practicable part besides the Pennsylvania Railroad and a
number of surface outcrops which I will mention, I will commence with
that.

_The Weehawken Tunnel_--This tunnel is now being cut through the
trap-rock for the New York, Ontario, and Western Railroad, and will
be completed in a few months, but will, probably, be available as a
mineralogical locality for a year to come. It is located about half a
mile south of the Weehawken Ferry from Forty-second Street, New York
city, and the place where to climb upon the hill to get to the shafts
leading to it is made prominent by the large body of light-colored rock
on the dump, a few rods north of where the east entrance is to be. The
western end is in the village of New Durham, on the New Jersey Northern
Railroad, and recognized by the immense earth excavations. A pass is
necessary to gain admittance down the shafts, and this can be procured
from the office of the company, between the third and fourth shafts to
the tunnel, in the grocery and provision store just to the north of
the tramway connecting the shafts on the surface. As it will not be
necessary to go down in any of the shafts besides the first and second
in order to fulfill the objects of this paper, no difficulty need be
encountered in procuring the pass if this is stated.

These two shafts are about eight hundred feet apart and one hundred and
seventy feet deep. A platform elevator is the mode of access to the
tunneled portion below, and a free shower-bath is included in the
descent; consequently, a rubber-coat and water tight boots are
necessary. A pair of overalls should be worn if one is to engage in
any active exploration below; candles should also be provided, as the
electric lights, at the face of the headings, give but little light, and
remind one very forcibly of a dim flash light with a foliaged tree in
front of it. The electric wires for supplying these arrangements run
along the north side of the tunnel for those on the east headings, and
on the south side for the west. They are excellent things to keep clear
of, as they have sufficient current passing through them to knock one
down; thus their position can be readily ascertained.

_Modes of Occurrence of the Minerals_.--In general, the greater number
of the specimens which are to be found in the tunnel occur in veins
generally perpendicular, and with other minerals of little or no value,
as calcite, chlorite, and imperfect crystals of the same mineral. A
few occur in nodules inclosed in the solid body of rock, and in which
condition they are seldom of value. The greater abundance are in the
veins of the dark-green soft chlorite, and some few in horizontal beds.
The minerals are found in the first condition by examining all the veins
running from floor to ceiling of the tunnel. The ores of calcite first
mentioned are very conspicuous, they being white in the dense black
rock. They may be chipped from, as there are about thirty or forty of
them exposed in each shaft, and the character of the minerals examined
to see if anything but calcite is in it. This is ascertained by a drop
of acid, as explained before, and by the descriptions given further on.
The veins of chlorite are not so conspicuous, being of a dark-green
color; but by probing along the walls with a stick or hammer, they may
be recognized by their softness, or by its dull glistening appearance.
They are comparatively few, but from an inch to three feet wide; and
minerals are found by digging it out with a stick or a three-foot drill,
to be had at the headings. Where the most minerals occur in the chlorite
is when plenty of veins of calcite are in its vicinity, and its edges
near the trap are dry and crumbly. It is here where the minerals are
found in this crumbly chlorite, and generally in geodes--that is, the
faces of the minerals all point inward, formerly a spherical mass--rough
and uncouth on the outside, and from half an inch to nearly a foot in
diameter. These are valuable finds, and well worth digging for. The beds
of minerals generally are of but one species, and will be mentioned
under the head of the minerals occurring in them. Besides, in the tunnel
there are generally more or less perfect minerals upon the main dump
over the edge of the bluff toward the river. Here many specimens that
have escaped the eyes of the miners may be found among the loose rock,
being constantly strewn out by the incline of the bed; in fact, this is
the only place in which quite a number of the incident minerals may be
found; but I will not linger longer on this, as I shall refer to it
under the minerals individually.

The minerals occurring at the tunnel are as follows, with their
descriptions and locations in the order of their greatest abundance:

_Calcite_.--This mineral occurs in great abundance in and about the
tunnel, and from all the shafts. There are two forms occurring there,
the most abundant of which is the rhombohedral, after Fig. 3. It can
generally be obtained, however, in excellent crystals, which, although
perfect in form, are opaque, but often large and beautiful. It is always
packed with a thousand or its multiple of other crystals into veins of a
few inches thick; and crystals are obtained by carefully breaking with
edge of the cold chisel these masses down to the fundamental form shown.
As the masses are never secured by the miners, they can always be picked
from the piles of _débris_ around the shafts and the dumps, and afford
some little instruction as to the manner in which a mineral is built up
by crystallization, and may be subdivided by cleavage to a crystal of
the same shape exactly, but infinitesimally small. A crystal to be worth
preserving should be about an inch in diameter, and as transparent as is
attainable.

Another form of calcite which is to be sparingly found is what is called
dogtooth spar, having the form shown in Fig. 4. They occur in clear
wine-yellow-colored crystals, from a quarter to half an inch in length;
they occur in the chlorite in geodes of variable sizes, but generally
two and a half inches in diameter, and which, when carefully broken in
half, showed beautiful grottoes of these crystals. The few of these that
I have found were in the four-foot vein of chlorite down the Shaft No.
1, to the west of the shaft about one hundred and fifty feet, and on
the south wall; it may be readily found by probing for it, and then the
geodes by digging in. There need be no difficulty in finding this vein
if these conditions are carefully considered, or if one of the miners
be asked as to the soft vein. Both these forms of calcite may be
distinguished from the other minerals by first effervescing on coming
in contact with the acids; second, by glowing with an intense (almost
unbearably so) light when heated with the blowpipe, but not fusing.
Their specific gravity is 2.6, or near it, and hardness about 3, or
equal to ordinary unpolished white marble.

_Natrolite_.--The finest specimens of this mineral that have ever been
found in Bergen Hill were taken from a bed of it in this tunnel, having
in its original form, before it was cut out by the tunnel passing
through, over one hundred square feet, and from one-half to two and a
half and even three inches in thickness; it was in all possible shapes
and forms--all extremely rare and beautiful. A large part of one end
of this bed still remains, and, by careful cutting, fine masses may be
obtained. This bed may be readily found; it is nearly horizontal, and in
its center about four feet from the floor of the tunnel, and about half
an inch thick. It is down Shaft No. 2, on the north wall, and commences
about eighty feet from the shaft. It is cut into in some places, but
there is plenty more left, and can be obtained by cutting the rock
above it and easing it out by means of the blade of a knife or similar
instrument. This natrolite is a grouping of very small but perfect
crystals, having the forms shown in Fig. 5; they are from a quarter to
an inch long, and, if not perfectly transparent, are of a pure white
color; they may be readily recognized by their form, and occurring in
this bed. Its hardness, which is seldom to be ascertained owing to the
delicacy of the crystals, is about 5, and the specific gravity 2.2.
This is readily found, but is no distinction; its reaction before the
blowpipe, however, is characteristic, it readily fusing to a transparent
globule, clear and glassy, and by forming a jelly when heated with
acids. The bed holding the upright crystals is also natrolite in
confused matted masses. This mineral has also been found in other parts
of the shaft, but only in small druses. There is a prospect at present
that another bed will be uncovered soon, and some more fine specimens to
be easily obtained.

_Pectolite_, or as it is termed by the miners, "silky spar."--This
mineral is quite abundant and in fine masses, not of the great beauty
and size of those taken from the Erie Tunnel, but still of great
uniqueness. The mineral is recognized by its peculiar appearance, as
is shown in Fig. 6, where it may be seen that it is in groups of
fine delicate fibers about an inch long, diverging from a point into
fan-shaped groups. The fibers are very tightly packed together, as are
also the groups; they are very tough individually, and have a hardness
of 4, and a specific gravity of about 2.5. It gelatinizes on boiling
with acid, and a fragment may be readily fused in the blowpipe flame,
yielding a transparent globule. The appearance is the most striking
characteristic, and at once distinguishes this mineral from any of the
others occurring in this locality. Considerable quantities of pectolite
may generally be found on the dump, but also in Shaft No. 1, and
especially No. 2. The veins of it are difficult to distinguish from the
calcite, as they are almost identical in color, and many of the calcite
veins are partly of pectolite--in fact, every third or fourth vein will
contain more or less of it. There is, however, a very fine vein of
pectolite about twenty-five feet further east from the natrolite bed; it
runs from the floor to ceiling, and is about two inches in thickness;
some specimens of which I took from these were unusually unique in both
size and appearance. It makes a very handsome specimen for the cabinet,
and should be carefully trimmed to show the characteristics of the
mineral.

_Datholite_.--This mineral has been found very frequently in the tunnel,
it occurring in pockets in the softer trap near the chlorite, and also
in the latter, generally at a depth of one hundred and fifty feet from
the surface, and consequently near the ceiling of the tunnel. All that
has been found of any great beauty has been in the western end of the
Shaft No. 1 and the eastern of Shaft No. 2, where the trap is quite
soft; here it is found nearly every day in greater or less quantity, and
from this some may generally be found on the dump, or, in the vein
of chlorite which I mentioned as a locality for the dogtooth spar,
considerable may be obtained in it and on its western edge near the
ceiling. A ladder about thirteen feet long is used for attending the
lights, and may generally be borrowed, and access to the remainder
of this pocket thus gained. Datholite is also very characteristic in
appearance, and can only be confounded with some forms of calcite
occurring near it. It occurs in small glassy, nearly globular crystals;
they are generally not over three-sixteenths of an inch in diameter, and
generally pure and perfectly transparent, having a hardness of a little
over 5, and specific gravity of 3; as it generally occurs as a druse
upon the trap, or an apopholite, calcite, etc., this is seldom
attainable, however, and we have a very distinctive characteristic in
another test: this is the blowpipe, under which it at first intumesces
and then fuses to a transparent globule, and the flame, after playing
upon it, is of a deep green color. Nitric acid must be used to boil it
up with, and with it it may be readily gelatinized. This last test will
seldom be necessary, however, and may be dispensed with if the hardness
and blowpipe reactions may be ascertained.

_Apopholite_.--This beautiful mineral has been found in fair abundance
at times in Shafts No. 1 and 2 in pockets, and seldom in place, most of
it being taken from the loose stone at the mouth of the shaft, and it
may generally be found on the dump. It is readily mistaken for calcite
by the miners and those unskilled in mineralogy, but a drop of acid will
quickly show the difference. The sizes of the crystals are very various,
from an eighth of an inch long or thick, to, in one case, an inch and
a half. The colors have been varied from white to nearly all tints,
including pink, purple, blue, and green; the white variety is, however,
the most abundant, and makes a handsome cabinet specimen. The crystals
are generally packed together in a mass, but are frequently set apart as
heavy druses of crystals having the form shown in Fig. 7. Sometimes,
as in the former grouping, the crystals are without the pyramidal
terminations, and are then right square prisms. The fracture being at
perfect right angles, distinguishes it from calcite. Its hardness is
generally fully 5, the specific gravity between 2.4 and 2.5; it is
difficult to fuse before the blowpipe, but is finally fused into an
opaque globule. Upon heating with nitric acid it partly dissolves, and
the remainder becomes flaky and gelatinous. Apopholite, although quite
rare, now may be bought from the men, or at least one of the engineers
of Shaft No. 2's elevator, and generally at low terms.

_Phrenite_.--This mineral is quite abundant in Shafts No. 1 and 2, in
very small masses, incrustations, and even in small crystals. It
occurs embedded in or incrusting the trap, and also with calcite and
apopholite. The only sure place to find it is at the southwest side of
an opening through the pile of drift rock under the trestle work of the
tramway, between shaft No. 1 and the dump, and within a few feet of a
number of wooden vats sunk into the ground seen just before descending
the hills and near the edge. Here on a number of blocks of trap it may
be found, a greenish white incrustation about as thick as a knife blade;
it also may be found on the main dump, and is sometimes found in plates
one-eighth of an inch thick, of a darker green color, upon calcite. Its
easiest distinguishment from the other minerals of this locality, with
which it might be confounded, is its great hardness of from 6 to 7.
It is very fragile and brittle, however, and is never perfectly
transparent, but quite opaque; its specific gravity is 2.9, and it is
readily fused before the blowpipe after intumescing. It partly dissolves
in acid without gelatinizing, leaving a flaky residue; it is a beautiful
mineral when in masses or crystals of a dark green color, but the best
place in the vicinity to secure specimens of this kind is, as I will
detail hereafter, at Paterson, N. J.

_Iron and Copper Pyrites_.--Both of these common but frequently
beautiful minerals occur in the tunnel and adjacent rocks in great
abundance. The crystals are generally about one-fourth of an inch in
diameter, and groups of these may be frequently obtained on the dump in
the shafts, especially No. 1 and 2, and where the rock is being cleared
away for the eastern entrance to the tunnel. They resemble each other
very much; the iron pyrites, however, is in cubical forms and having the
great hardness of from 6 to 7, while the copper pyrites, less abundant
and in forms having triangles for bases, but having sometimes other
forms and a hardness of but 3 to 4. Both are similar in aspect to a
piece of brass, and cannot be mistaken for any other mineral. The form
of the copper pyrites is shown in Fig. 8; the iron is, as before noted,
in cubes, more or less modified.

_Stilbite_.--Small quantities of this beautiful mineral have been found
in Shaft No. 2, in a small bed of but a few square feet in area, but
quite thick and appearing much like natrolite. This bed was about one
hundred feet east from Shaft No. 2, and in the center of the heading
when it was at that point. It has been encountered since in small
quantities, and it would do well to look out for it in the fresh
tunneled portion after the date appended to this paper. It generally
occurs in the form shown in Fig. 9, grouped very similarly to natrolite,
and being right upon the rock or a thin bed of itself. The crystals are
generally half an inch long, but often less. The modifications of the
above form, which are frequent in this species, strike one forcibly of
the resemblance they bear to a broad stone spear head on a diminutive
scale, with a blunted edge; their hardness is about 4, specific gravity
2.2, the color generally a pearly white or grayish. After a long
boiling with nitric acid it gelatinizes, but it foams up and fuses to a
transparent glass before the blowpipe. A little stilbite may often be
found on the dumps.

_Laumonite_ occurs in very small quantities on calcite or apopholite,
and can hardly be expected to be found on the trip; but as it might be
found, I will detail some of its characteristics. Hardness 4, specific
gravity 2.3; it generally occurs in small crystals, but more frequently
in a crumbly, chalky mass, which it becomes upon exposure to the air.
The crystals are generally transparent and frequently tinged yellow in
color. It gelatinizes by boiling with acid, and after intumescing before
the blowpipe, fuses to a frothy mass. To keep this mineral when in
crystals from crumbling upon exposure it may be dipped in a thin mastic
varnish or in a gum-arabic solution.

_Heulandite_.--This rare mineral has been found under the same
conditions as laumonite in Shaft No. 2, but it is seldom to be met with,
and then in small crystals. It is of a pure white color, sometimes
transparent. It intumesces and readily fuses before the blowpipe, and
dissolves in acid without gelatinizing. Hardness 4, specific gravity
2.2.

The few other minerals occurring in the tunnel are so extremly rare as
not to be met with by any other than an expert, and it is impossible
to detail the localities, as they generally occur as minute druses or
incrustations upon other minerals with which they may be confounded, and
have been removed as soon as discovered. The minerals referred to are
analcime, chabazite, Thompsonite, and finally, the mineral which I first
found in this formation, Hayesine, which is extremely rare, and of which
I only obtained sufficient to cover a square inch. The particulars in
regard to its locality, etc., maybe found in the _American Journal of
Sciences_ for June, page 458. I will now sum up the characteristics of
these several minerals of this locality in the table:

-------------------------------------------------------------------------------
          |     |   |                 |                 |      |
   Name.  |  H. |Sp.|Action of        |Action of        |Color.|Appearance.
          |     |Gr.|Blowpipe.        |hot acid.        |      |
----------+-----+---+-----------------+-----------------+------+---------------
          |     |   |                 |                 |      |
Calcite   |  3  |2.6|Infusible,       |Soluble with     |White |Like Fig.
          |     |   |but glows        |effervescence    |      |3 and 4.
          |     |   |                 |                 |      |
Natrolite |  5  |2.2|Readily fused    |Forms a jelly    |  do. |Like Fig 5.
          |     |   |to clear globule |                 |      |
          |     |   |                 |                 |      |
Pectolite |  4  |2.5|      do.        |  do.  do.       |  do. |Divergent
          |     |   |                 |                 |      |fibers, Fig. 6.
          |     |   |                 |                 |      |
Datholite |  5  |3.0|Intumesces, fused|Forms a jelly    |Color-|Small, nearly
          |     |   |to clear globule,|                 |less  |spherical, etc.
          |     |   |gives green flame|                 |white |
          |     |   |                 |                 |      |
Apopholite|  5  |2.5|Difficult, fused |Partly soluble   |Tinted|Like Fig. 7.
          |     |   |to opaque globule|in nitric acid   |      |
          |     |   |                 |                 |      |
Phrenite  |  6  |2.9|Intomesces, fused|Partly soluble   |Green-|In tables and
          |to 7 |   |to clear globule |in nitric acid,  |ish   |incrustations.
          |     |   |                 |leaving flakes   |      |
          |     |   |                 |                 |      |
Iron      |  6  |5.0|Burns and yields |                 |Brass |Cubical.
pyrites   |to 7 |   |a black globule, |                 |      |
          |     |   |decrepitates     |                 |      |
          |     |   |                 |                 |      |
Copper    |  3  |4.2|    do.     do.  |                 |  do. |Tetrahedronal.
pyrites   |to 4 |   |                 |                 |      |
          |     |   |                 |                 |      |
Stilbite  |  4  |2.2|Intumesces and   |Difficult; jelly |White |Like Fig. 8.
          |     |   |fuses readily    |on long boiling  |      |
          |     |   |                 |with nitric acid.|      |
          |     |   |                 |                 |      |
Laumonite |  4  |2.3|Intumesces and   |Readily          |  do. |Generally
          |to 0 |   |fuses to frothy  |gelatinizes      |      |chalky.
          |     |   |mass             |                 |      |
          |     |   |                 |                 |      |
Heulandite|  4  |2.2|Intumesces and   |Soluble, no      |  do. |In right
          |     |   |readily fuses    |jelly            |      |rhomboidal
          |     |   |                 |                 |      |prisms.
          |     |   |                 |                 |      |
-------------------------------------------------------------------------------

_To Distinguish the Minerals together the one from the other_.--Calcite
by effervescing on placing a drop of acid upon it. Natrolite resembles
stilbite, but may be distinguished by gelatinizing readily with
hydrochloric acid and by not intumescing when heated before the
blowpipe; from the other minerals by the form of the crystals and their
setting, also the locality in the tunnel in which it was found.

Pectolite sometimes resembles some of the others, but may be readily
distinguished by its _tough_ long fibers, not brittle like natrolite.
Datholite may generally be distinguished by the form of its crystals and
their glassy appearance, with great hardness, and by tingeing the flame
from the blowpipe of a true green color. Apopholite is distinguished
from calcite, as noticed under that species, and from the others by its
form, difficult fusibility, and part solubility.

Phrenite is characterized by its hardness, greenish color, occurrence,
and action of acid. Iron pyrites is always known by its brassy metallic
aspect and great hardness. Copper pyrites, by its aspect from the other
minerals, and from iron pyrites by its inferior hardness and less
gravity.

Stilbite is characterized by its form, difficult gelatinizing, and
intumescence before the blowpipe; from natrolite as mentioned under that
species.

Laumonite is known by its generally chalky appearance and a probable
failure in finding it.

Heulandite is distinguished from stilbite by its crystals and perfect
solubility; from apopholite by form of crystals.

In the next part of this paper I will commence with Staten Island.

July 1, 1882. (_To be continued_.)

       *       *       *       *       *




ANTISEPTICS.


The author has endeavored to ascertain what agents are able to destroy
the spores of bacilli, how they behave toward the microphytes most
easily destroyed, such as the moulds, ferments, and micrococci, and if
they suffice at least to arrest the development of these organisms in
liquids favorable to their multiplication. His results with phenol,
thymol, and salicylic acid have been unfavorable. Sulphurous acid
and zinc chloride also failed to destroy all the germs of infection.
Chlorine, bromine, and mercuric chloride gave the best results;
solutions of mercuric chloride, nitrate, or sulphate diluted to 1 part
in 1,000 destroy spores in ten minutes.--_R. Koch_.

       *       *       *       *       *




CRYSTALLIZATION AND ITS EFFECTS UPON IRON.

By N.B. WOOD, Member of the Civil Engineers' Club, of Cleveland.

[Footnote: Read January 10th. 1882.]


The question has been asked, "What is the chemically scientific
definition of crystallization?" Now as the study of crystallization and
its effect upon matter, physically as well as chemically, will be of
interest, considering the subject matter for discussion, I shall not
only endeavor to answer the question, as I understand it, but try to
treat it somewhat technologically.

Having this object in view, I have prepared or brought about the
conditions necessary to the formation of a few crystals of various
chemical substances, which for various reasons, such as lack of time and
bad weather, are not as perfect as could be desired, but will perhaps
subserve the purpose for which they were designed. I think you will
agree with me that they are beautiful, if they are imperfect, and I can
assure you that the pleasure of watching their formation fully repays
one for the trouble, if for no other reason than the mere gratification
of the senses. From the earliest times and by all races of men, the
crystal has been admired and imitated, or improved by cutting and
polishing into faces of various substances. I have also procured
specimens of steel and iron which show the effect of crystallization,
which was produced (perhaps) under known conditions, so that the
conclusions which we arrive at from their study will have a fair chance
of being logical, at least, and perhaps of some practical value.

When we examine inanimate nature we find two grand divisions of matter,
_fluid_ and _solid_. These two divisions may be subdivided into, the
former gaseous and liquid, the latter amorphous and crystalline; but
whether one or the other of these divisions be considered, their
ultimate and common division will be the ATOM. By the atom we understand
that portion of matter which admits of no further division, which,
though as inconceivable for minuteness as space is for extent, has still
definite weight, form, and volume; which under favorable circumstances,
has that power or force called cohesion, the intensity of which
constitutes strength of material, which every engineer is supposed to
understand, but which lies far beyond the powers of the human mind for
comprehension or analysis. When we apply a magnet to a mass of iron
filings, we observe the particles arrange themselves in regular order,
having considerable strength in one direction, and very little or none
in any other. Now, although we understand very little about the force
which holds these particles in position, we do know that it is actual
force applied from without and maintained at the expense of some of the
known sources of force. But the force or power or property of cohesion
seems to be a quality stored within the atom itself, in many cases
similar to magnetism, having powerful attraction in some directions
and very little or none in others. A crystal of mica, for instance, or
gypsum may be divided to any degree of thinness, but is very difficult
to even break. This property of crystals is termed cleavage. Cohesion
and crystallization are affected variously by various circumstances,
such as heat or its absence, motion or its absence, etc. In fact, almost
every phenomenon of nature within the range of ordinary temperatures
has effects which may be favorable to the crystallization of some
substances, and at the same time unfavorable to others; so it will be
seen that it is impossible to lay down any rule for it except for named
substances, like substances requiring like conditions, to bring its
atoms into that state of equilibrium where crystallization can occur.
If we examine crystals carefully we find, not only that nature has here
provided geometric forms of marvelous beauty and exactness, with faces
of polish and quoins of acuteness equal to the work of the most skillful
lapidist, "but that in whatever manner or under whatever circumstances a
crystal may have been formed, whether in the laboratory of the chemist
or the workshop of nature, in the bodies of animals or the tissues of
plants, up in the sky or in the depths of the earth, whether so rapidly
that we may literally see its growth, or by the slow aggregation of its
molecules during perhaps thousands of years, we always find that the
arrangement of the faces is subject to fixed and definite laws." We find
also that a crystal is always finished and has its form as perfectly
developed when it is the minutest point discernible by the microscope as
when it has attained its ultimate growth. I might add parenthetically
that crystals are sometimes of immense size, one at Milan of quartz
being 3 feet 3 inches long and 5 feet 6 inches in circumference, and is
estimated to weigh over 800 pounds; and a gigantic beryl at Grafton, N.
H., is over 4 feet in length and 32 inches in diameter, and weighs not
less than 5,000 pounds; but the most perfect specimens are of small
size, as some accident is sure to overtake the larger ones before they
acquire their growth, to interfere with their symmetry or transparency.
This you will see abundantly illustrated by the examples which I have
prepared, as also the constancy of the angles of like faces. Chemically
speaking, the crystal is always a perfect chemical body, and can never
be a mechanical mixture. This fact has been of great value to the
science of chemistry in developing the atomic theory, which has
demonstrated that a body can only exist chemically combined when a
definite number of atoms of each element is present, and that there is
no certainty of such proportions existing except in the crystal. I
hold before you a crystal of common alum. Its chemical symbol would be
Al_{2}O_{3},3SO_{3}+KO,SO_{3}+24H_{2}O. If we knew its weight and wished
to know its ultimate component parts, we could calculate them more
readily than we could acquire that knowledge by any other means. But the
elements of this quantity of uncrystallized alum could not be computed.
Then we may define crystallization to be the operation of nature wherein
the chemical atoms or molecules of a substance have sufficient polarized
force to arrange themselves about a central attracting point in definite
geometrical forms.

Fresenius defines it thus: "_Every operation, or process, whereby bodies
are made to pass from the fluid to the solid state, and to assume_
certain fixed, _mathematically definable, regular forms_." It would be
folly for me to attempt to criticise Fresenius, but I give you both
definitions, and you can take your choice. The definition of Fresenius,
however, will not suit our present purpose, because the crystallization
of wrought iron occurs, or seems to, _after_ the iron has acquired a
_solid state_.

Iron, as you all know, is known to the arts in three forms: cast or
crude, steel, and wrought or malleable. Cast iron varies much in
chemical composition, being a mixture of iron and carbon chiefly, as
constant factors, with which silicium in small quantities (from 1 to
5 per cent.), phosphorus, sulphur, and sometimes manganese (e.g.
spiegeleisen) and various other elements are combined. All of these have
some effect upon the crystalline structure of the mass, but whatever
crystallization takes place occurs at the moment of solidification, or
between that and a red heat, and varies much, according to the time
occupied in cooling, as to its composition. My own experience leads me
to think that a cast iron having about 3 per cent. of carbon, a small
per centage of phosphorus, say about ½ of 1 per cent., and very small
quantities of silicium, the less the better, and traces of manganese
(the two latter substances _slagging_ out almost entirely during the
process of remelting for casting), makes a metal best adapted to the
general use of the founder. Such proportions will make a soft, even
grained, dark gray iron, whose crystals are small and bright, and whose
fracture will be uneven and sharp to the touch. The phosphorus in this
instance gives the metal liquidity at a low temperature, but does not
seem to influence the crystallization to any appreciable extent. The two
elements to be avoided by the founder are silicium and sulphur. These
give to iron a peculiar crystalline appearance easily recognized by
an experienced person. Silicium seems to obliterate the sparkling
brilliancy of the crystalline faces of good iron, and replace them with
very fine dull ones only discernible with a lens, and the iron breaks
more like stoneware than metal, while sulphur in appreciable quantities
gives a striated crystalline texture similar to chilled iron, and very
brittle. Phosphorus in very large quantities acts similarly. The form of
the crystal in cast iron is the octahedron, so that right angles with
sharp corners should be avoided as much as possible in castings, as the
most likely position for a crystal to take would be with its faces along
the line of the angle. Steel, to be of any value as such, _must_ be made
of the purest material. Phosphorus and sulphur _must_ not exist, except
in the most minute quantities, or the metal is worthless. If either of
these substances be present in a bar of steel, its structure will
be coarse, crystalline and weak. The reason of this is unknown, but
probably their presence reduces the power of cohesion; and, that being
reduced, gives the molecules of steel greater freedom to arrange
themselves in conformity with their polarity, and this in its turn again
weakens the mass by the tendency of the crystals to cleavage in certain
directions. Carbon is a constant element in steel, as it is in cast
iron, but is frequently replaced by chromium, titanium, etc., or is said
to be, though it is not quite clear to me how it can be so if steel is
a chemical compound. However this may be, we know that a piece of good
soft steel breaks with a fine crystalline fracture, and the same piece
hardened when broken shows either an amorphous structure or one very
finely crystalline, which would indicate that the crystals had been
broken up by the action of heat, and that they had not had sufficient
time to return to their original position on account of the sudden
cooling. The tendency of the molecules of steel after hardening to
assume their natural position when cold seems to be very great, for we
have often seen large pieces of steel burst asunder after hardening,
though lying untouched, and sometimes with such force as to hurl the
fragments to some distance. If a piece of steel be subjected to a bright
yellow or white heat its nature is entirely changed, and the workman
says it is burnt. Though this is not actually a fact, it does well
enough to express that condition of the metal. Steel cannot be burnt
unless some portion of it has been oxidized. The carbon would of course
be attacked first, its affinity for oxygen being greatest; but we find
nothing wanting in a piece of burnt steel. It can, by careful heating,
hammering and hardening, be returned to its former excellence. Then what
change has taken place? I should say that two modifications have been
made, one physical, the other chemical. The change chemically is that
of a chemical compound to a mixture of carbon and iron, so that in a
chemical sense it resembles cast iron. The change physically is that of
crystallization, being due partly to chemical change and partly to the
effect of heat. I have procured a specimen of steel showing beautifully
the effect of overheating. The specimen is labeled No. 1, and is a piece
of Park Brothers' steel (one of the best brands made in America). It has
been heated at one end to proper heat for hardening, and at the other is
what is technically called "burnt." It has been broken at intervals
of about 1½ inches, showing the transition from amorphous or proper
hardening to highly crystalline or "burnt." Malleable or wrought iron
is or should be pure iron. Of course in practice it is seldom such, but
generally nearly so, being usually 98, 99, or even more per cent. It is
exceedingly prone to crystallization, the purer varieties being as much
subject to it as others, except those contaminated with phosphorus,
which affects it similarly with steel, and makes it very weak to cross
and tensile strains. I have never estimated the quantity present in any
except one specimen, a bar of 1½ round, which literally fell to pieces
when dropped across a block of iron. It had 1.32 per cent. of phosphorus
and was very crystalline, though the crystals were not very large. Iron
which has been, when first made, quite fibrous, when subjected to a
series of shocks for a greater or less period, according to their
intensity, when subjected to intense currents of electricity, or when
subjected to high temperatures, or has by mechanical force been pushed
together, or, as it is called, upset, becomes extremely crystalline.
Under all of these circumstances it is subjected to one physical
phenomenon, that of motion. It would seem that if a bar of iron were
struck, the blow would shake the whole mass, and consequently the
relative position of the particles remain unchanged, but this is not the
case. When the blow is struck it takes an appreciable length of time for
the effect to be communicated to the other end so as to be heard, if the
distance is great. This shows that a small force is communicated from
particle to particle independently along the whole mass, and that each
atom actually moves independently of its neighbor. Then, if there be
any attraction at the time tending to arrange it differently, it will
conform to it. So much for theory with regard to this important matter.
It looks well on paper, but do the facts of the case correspond? If
practically demonstrated and systematically executed, experiments fail
to corroborate the theory, and if, furthermore, we find there is no
necessity for the theory, we naturally conclude that it is all wrong,
or, at least, imperfectly understood. Now there is one other quality
imparted to iron by successive shocks, which, I think, is independent
of crystallization, and this quality is hardness and consequent
brittleness. One noticeable feature about this also is, that as
"absolute cohesion" or tensile strength diminishes, "relative cohesion"
or strength to resist crushing increases. Specimens Nos. 2, 3, and 4 are
pieces of Swedish iron, probably from the celebrated mines of Dannemora.
Nos. 2 and 3 are parts of the same bolt, which, after some months' use
on a "heading machine" in a bolt and nut works, where it was subjected
to numerous and violent shocks, (perhaps 50,000 or 60,000 per day),
it broke short off, as you see in No 2, showing a highly crystalline
fracture. To test whether this structure continued through the bolt, I
had it nicked by a blacksmith's cold chisel and broken. The specimen
shows that it is still stronger at that point than at the point where
it is actually broken, but the resulting fracture shows the same
crystalline appearance. I next had specimen No. 4 cut from a fresh
bar of iron which had never been used for anything. It also shows a
crystalline fracture, indicating that this peculiarity had existed in
the iron of both from the beginning.

I next took specimen No. 3 and subjected it to a careful annealing,
taking perhaps two hours in the operation. Although it is a 1-1/8 bolt
and has V threads cut upon it we were unable to break it, although bent
cold through an arc of 90°, and probably would have doubled upon itself
if we had had the means to have forced it. Now what does this show? Have
the crystals been obliterated by the process of annealing, or has only
their cleavage been destroyed, so that when they break, instead of
showing brilliant, sparkling faces, they are drawn into a fibrous
looking mass? The latter seems to be the most plausible theory, to which
I admit objections may be raised. For my own part, I am inclined to the
belief that the crystal exists in all iron which is finished above a
bright red heat, and that between that and black heat they are formed
and have whatever characteristics circumstances may confer upon them,
modified by the action of agencies heretofore mentioned.

       *       *       *       *       *

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