Produced by J. Paolucci, D. Kretz, J. Sutherland, and
Distributed Proofreaders










[Illustration]




SCIENTIFIC AMERICAN SUPPLEMENT NO. 417




NEW YORK, DECEMBER 29, 1883

Scientific American Supplement. Vol. XVI, No. 417.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.


       *       *       *       *       *

TABLE OF CONTENTS

I.   ENGINEERING AND MECHANICS.--Machine for Making Electric
     Light Carbons.--2 figures

     The Earliest Gas Engine

     The Moving of Large Masses.--With engravings of the removal
     of a belfry at Cresentino in 1776, and of the winged bulls from
     Nineveh to Mosul in 1854

     Science and Engineering.--The relation they bear to one another.
     By WALTER R. BROWNE

     Hydraulic Plate Press.--With engraving

     Fast Printing Press for Engravings.--With engraving

     French Cannon

     Apparatus for Heating by Gas.--5 figures

     Improved Gas Burner for Singeing Machines.--1 figure

II.  TECHNOLOGY.--China Grass, or Rhea.--Different processes and
     apparatus used in preparing the fiber for commerce

III. ARCHITECTURE.--Woodlands, Stoke Pogis, Bucks.--With engraving.

IV.  ELECTRICITY, LIGHT, ETC.--Volta Electric Induction as Demonstrated
     by Experiment.--Paper read by WILLOUGHBY SMITH before the Society
     of Telegraph Engineers and Electricians.--Numerous figures

     On Telpherage.--The Transmission of vehicles by electricity to a
     distance.--By Prof. FLEEMING JENKIN

     New Electric Battery Lights

     The Siemens Electric Railway at Zankeroda Mines.--3 figures

     Silas' Chronophore.--3 figures

V.   NATURAL HISTORY.--A New Enemy of the Bee

     Crystallization of Honey

     An Extensive Sheep Range

VI.  HORTICULTURE, ETC.--The Zelkowas.--With full description
     of the tree, manner of identification, etc., and several
     engravings showing the tree as a whole, and the leaves,
     fruit, and flowers in detail

VII. MEDICINE, HYGIENE, ETC.-The Disinfection of the Atmosphere.
     --Extract from a lecture by Dr. R.J. LEE, delivered at the
     Parkes Museum of Hygiene. London

     A New Method of Staining Bacillus Tuberculosis

     Cure for Hemorrhoids

       *       *       *       *       *




VOLTA-ELECTRIC INDUCTION.

[Footnote: A paper read at the Society of Telegraph Engineers and
Electricians on the 8th November, 1883]

By WILLOUGHBY SMITH.


In my presidential address, which I had the pleasure of reading before
this society at our first meeting this year, I called attention,
somewhat hurriedly, to the results of a few of my experiments on
induction, and at the same time expressed a hope that at a future date I
might be able to bring them more prominently before you. That date has
now arrived, and my endeavor this evening will be to demonstrate to you
by actual experiment some of what I consider the most important results
obtained. My desire is that all present should see these results, and
with that view I will try when practicable to use a mirror reflecting
galvanometer instead of a telephone. All who have been accustomed to the
use of reflecting galvanometers will readily understand the difficulty,
on account of its delicacy, of doing so where no special arrangements
are provided for its use; but perhaps with a little indulgence on your
part and patience on mine the experiments may be brought to a successful
issue.

[Illustration: VOLTA-ELECTRIC INDUCTION.]

Reliable records extending over hundreds of years show clearly with what
energy and perseverance scientific men in every civilized part of the
world have endeavored to wrest from nature the secret of what is termed
her "phenomena of magnetism," and, as is invariably the case under
similar circumstances, the results of the experiments and reasoning of
some have far surpassed those of others in advancing our knowledge. For
instance, the experimental philosophers in many branches of science were
groping as it were in darkness until the brilliant light of Newton's
genius illumined their path. Although, perhaps, I should not be
justified in comparing Oersted with Newton, yet he also discovered what
are termed "new" laws of nature, in a manner at once precise, profound,
and amazing, and which opened a new field of research to many of the
most distinguished philosophers of that time, who were soon engaged in
experimenting in the same direction, and from whose investigations arose
a new science, which was called "electro-dynamics." Oersted demonstrated
from inductive reasoning that every conductor of electricity possessed
all the known properties of a magnet while a current of electricity was
passing through it. If you earnestly contemplate the important adjuncts
to applied science which have sprung from that apparently simple fact,
you will not fail to see the importance of the discovery; for it was
while working in this new field of electro-magnetism that Sturgeon made
the first electro-magnet, and Faraday many of his discoveries relating
to induction.

Soon after the discovery by Oersted just referred to, Faraday, with the
care and ability manifest in all his experiments, showed that when an
intermittent current of electricity is passing along a wire it induces
a current in any wire forming a complete circuit and placed parallel
to it, and that if the two wires were made into two helices and placed
parallel to each other the effect was more marked. This Faraday
designated "Volta-electric induction," and it is with this kind of
induction I wish to engage your attention this evening; for it is a
phenomenon which presents some of the most interesting and important
facts in electrical science.

Here are two flat spirals of silk-covered copper wire suspended
separately, spider-web fashion, in wooden frames marked respectively A
and B. The one marked A is so connected that reversals at any desired
speed per minute from a battery of one or more cells can be passed
through it. The one marked B is so connected to the galvanometer and a
reverser as to show the deflection caused by the induced currents, which
are momentary in duration, and in the galvanometer circuit all on the
same side of zero, for as the battery current on making contact produces
an induced current in the reverse direction to itself, but in the same
direction on breaking the contact, of course the one would neutralize
the other, and the galvanometer would not be affected; the galvanometer
connections are therefore reversed with each reversal of the battery
current, and by that means the induced currents are, as you perceive,
all in the same direction and produce a steady deflection. The
connections are as shown on the sheet before you marked 1, which I think
requires no further explanation.

Before proceeding, please to bear in mind the fact that the inductive
effects vary inversely as the square of the distance between the two
spirals, when parallel to each other; and that the induced current in
B is proportional to the number of reversals of the battery current
passing through spiral A, and also to the strength of the current so
passing. Faraday's fertile imagination would naturally suggest the
question, "Is this lateral action, which we call magnetism, extended to
a distance by the action of intermediate particles?" If so, then it is
reasonable to expect that all substances would not be affected in the
same way, and therefore different results would be obtained if different
media were interposed between the inductor and what I will merely call,
for distinction, the inductometer.

With a view to proving this experimentally, Faraday constructed three
flat helices and placed them parallel to each other a convenient
distance apart. The middle helix was so arranged that a voltaic current
could be sent through it at pleasure. A differential galvanometer was
connected with the other helices in such a manner that when a voltaic
current was sent through the middle helix its inductive action on
the lateral helices should cause currents in them, having contrary
directions in the coils of the galvanometer. This was a very prettily
arranged electric balance, and by placing plates of different substances
between the inductor and one of the inductometers Faraday expected to
see the balance destroyed to an extent which would be indicated by the
deflection of the needle of the galvanometer. To his surprise he found
that it made not the least difference whether the intervening space was
occupied by such insulating bodies as air, sulphur, and shellac, or such
conducting bodies as copper and the other non-magnetic metals. These
results, however, did not satisfy him, as he was convinced that the
interposition of the non-magnetic metals, especially of copper, did
have an effect, but that his apparatus was not suitable for making it
visible. It is to be regretted that so sound a reasoner and so careful
an experimenter had not the great advantage of the assistance of
such suitable instruments for this class of research as the
mirror-galvanometer and the telephone. But, although he could not
practically demonstrate the effects which by him could be so clearly
seen, it redounds to his credit that, as the improvement in instruments
for this kind of research has advanced, the results he sought for have
been found in the direction in which he predicted.

A and B will now be placed a definite distance apart, and comparatively
slow reversals from ten Leclanché cells sent through spiral A; you will
observe the amount of the induced current in B, as shown on the scale of
the galvanometer in circuit with that spiral. Now midway between the two
spirals will be placed a plate of iron, as shown in Plate 2, and at once
you observe the deflection of the galvanometer is reduced by less than
one half, showing clearly that the presence of the iron plate is in some
way influencing the previous effects. The iron will now be removed, but
the spirals left in the same position as before, and by increasing the
speed of the reversals you see a higher deflection is given on the
galvanometer. Now, on again interposing the iron plate the deflection
falls to a little less than one-half, as before. I wish this fact to be
carefully noted.

The experiment will be repeated with a plate of copper of precisely the
same dimensions as the iron plate, and you observe that, although the
conditions are exactly alike in both cases, the interposition of the
copper plate has apparently no effect at the present speed of the
reversals, although the interposition of the iron plate under the same
conditions reduced the deflection about fifty per cent. We will now
remove the copper plate, as we did the iron one, and increase the speed
of the reversals to the same as in the experiment with the iron, and you
observe the deflection on the galvanometer is about the same as it was
on that occasion. Now, by replacing the copper plate to its former
position you will note how rapidly the deflection falls. We will now
repeat the experiment with a plate of lead; you will see that, like the
copper, it is unaffected at the low speed, but there the resemblance
ceases; for at the high speed it has but very slight effect. Thus these
metals, iron, copper, and lead, appear to differ as widely in their
electrical as they do in their mechanical properties. Of course it would
be impossible to obtain accurate measurements on an occasion like the
present, but careful and reliable measurements have been made, the
results of which are shown on the sheet before you, marked 3.

It will be seen by reference to these results that the percentage of
inductive energy intercepted does not increase for different speeds of
the reverser in the same rate with different metals, the increase with
iron being very slight, while with tin it is comparatively enormous. It
was observed that time was an important element to be taken into account
while testing the above metals, that is to say, the lines of force took
an appreciable time to polarize the particles of the metal placed in
their path, but having accomplished this, they passed more freely
through it.

Now let us go more minutely into the subject by the aid of Plate IV.,
Figs. 1 and 2. In Fig. 1 let A and B represent two flat spirals, spiral
A being connected to a battery with a key in circuit and spiral B
connected to a galvanometer; then, on closing the battery circuit, an
instantaneous current is induced in spiral B. If a non-magnetic metal
plate half an inch thick be placed midway between the spirals, and the
experiment repeated, it will be found that the induced current received
by B is the same in amount as in the first case. This does not prove,
as would at first appear, that the metal plate fails to intercept the
inductive radiant energy; and it can scarcely be so, for if the plate is
replaced by a coil of wire, it is found that induced currents are set
up therein, and therefore inductive radiant energy must have been
intercepted. This apparent contradiction may be explained as follows:

In Fig. 2 let D represent a source of heat (a vessel of boiling water
for instance) and E a sensitive thermometer receiving and measuring the
radiant heat. Now, if for instance a plate of vulcanite is interposed,
it cuts off and absorbs a part of the radiant heat emitted by D, and
thus a fall is produced in the thermometer reading. But the vulcanite,
soon becoming heated by the radiant heat cut off and absorbed by itself,
radiates that heat and causes the thermometer reading to return to about
its original amount. The false impression is thus produced that the
original radiated heat was unaffected by the vulcanite plate; instead of
which, as a matter of fact, the vulcanite plate had cut off the radiant
heat, becoming heated itself by so doing, and was consequently then the
radiating body affecting the thermometer.

The effect is similar in the case of induction between the two spirals.
Spiral A induces and spiral B receives the induced effect. The metal
plate being then interposed, cuts off and absorbs either all or part of
the inductive radiant energy emitted by A. The inductive radiant energy
thus cut off, however, is not lost, but is converted into electrical
energy in the metal plate, thereby causing it to become, as in the case
of the vulcanite in the heat experiment, a source of radiation which
compensates as far as spiral B is concerned for the original inductive
radiant energy cut off. The only material difference noticeable in
the two experiments is that in the case of heat the time that elapses
between the momentary fall in the thermometer reading (due to the
interception by the vulcanite plate of the radiant beat) and the
subsequent rise (due to the interposing plate, itself radiating that
heat) is long enough to render the effect clearly manifest; whereas in
the case of induction the time that elapses is so exceedingly short
that, unless special precautions are taken, the radiant energy emitted
by the metal plate is liable to be mistaken for the primary energy
emitted by the inducing spiral.

The current induced in the receiving spiral by the inducing one is
practically instantaneous; but on the interposition of a metal plate
the induced current which, as before described, is set up by the plate
itself has a perceptible duration depending upon the nature and mass of
metal thus interposed. Copper and zinc produce in this manner an induced
current of greater length than metals of lower conductivity, with the
exception of iron, which gives an induced current of extremely short
duration. It will therefore be seen that in endeavoring to ascertain
what I term the specific inductive resistance of different metals by
the means described, notice must be taken of and allowance made for
two points. First, that the metal plate not only cuts off, but itself
radiates; and secondly, that the duration of the induced currents
radiated by the plates varies with each different metal under
experiment.

This explains the fact before pointed out that the apparent percentage
of inductive radiant energy intercepted by metal plates varies with the
speed of the reversals; for in the case of copper the induced current
set up by such a plate has so long a duration that if the speed of the
reverser is at all rapid the induced current has not time to exhaust
itself before the galvanometer is reversed, and thus the current being
on the opposite side of the galvanometer tends to produce a lower
deflection. If the speed of the reverser be further increased, the
greater part of the induced current is received on the opposite terminal
of the galvanometer, so that a negative result is obtained.

We know that it was the strong analogies which exist between electricity
and magnetism that led experimentalists to seek for proofs that would
identify them as one and the same thing, and it was the result of
Professor Oersted's experiment to which I have already referred that
first identified them.

Probably the time is not far distant when it will be possible to
demonstrate clearly that heat and electricity are as closely allied;
then, knowing the great analogies existing between heat and light, may
we not find that heat, light, and electricity are modifications of
the same force or property, susceptible under varying conditions of
producing the phenomena now designated by those terms? For instance,
friction will first produce electricity, then heat, and lastly light.

As is well known, heat and light are reflected by metals; I was
therefore anxious to learn whether electricity could be reflected in
the same way. In order to ascertain this, spiral B was placed in this
position, which you will observe is parallel to the lines of force
emitted by spiral A. In this position no induced current is set up
therein, so the galvanometer is not affected; but when this plate of
metal is placed at this angle it intercepts the lines of force, which
cause it to radiate, and the secondary lines of force are intercepted
and converted into induced currents by spiral B to the power indicated
by the galvanometer. Thus the phenomenon of reflection appears to be
produced in a somewhat similar manner to reflection of heat and light.
The whole arrangement of this experiment is as shown on the sheet before
you numbered 5, which I need not, I think, more fully explain to you
than by saying that the secondary lines of force are represented by the
dotted lines.

Supported in this wooden frame marked C is a spiral similar in
construction to the one marked B, but in this case the copper wire is
0.044 inch in diameter, silk-covered, and consists of 365 turns, with
a total length of 605 yards; its resistance is 10.2 ohms, the whole is
inclosed between two thick sheets of card paper. The two ends of the
spiral are attached to two terminals placed one on either side of the
frame, a wire from one of the terminals is connected to one pole of a
battery of 25 Leclanche cells, the other pole being connected with one
terminal of a reverser, the second terminal of which is connected to the
other terminal of the spiral.

Now, if this very small spiral which is in circuit with the galvanometer
and a reverser be placed parallel to the center of spiral C, a very
large deflection will be seen on the galvanometer scale; this will
gradually diminish as the smaller spiral is passed slowly over the face
of the larger, until on nearing the edge of the latter the smaller
spiral will cease to be affected by the inductive lines of force from
spiral C, and consequently the galvanometer indicates no deflection. But
if this smaller spiral be placed at a different angle to the larger
one, it is, as you observe by the deflection of the galvanometer, again
affected. This experiment is analogous to the one illustrated by diagram
6, which represents the result of an experiment made to ascertain the
relative strength of capability or producing inductive effects of
different parts of a straight electro-magnet.

A, Fig. 1, represents the iron core, PP the primary coil, connected
at pleasure to one Grove cell, B, by means of the key, K; S, a small
secondary coil free to move along the primary coil while in circuit with
the galvanometer, G. The relative strength of any particular spot can be
obtained by moving the coil, S, exactly over the required position. The
small secondary coil is only cut at right angles when it is placed in
the center of the magnet, and as it is moved toward either pole so the
lines of force cut it more and more obliquely. From this it would appear
that the results obtained are not purely dependent upon the strength of
the portion of the magnet over which the secondary coil is placed, but
principally upon the angle at which the lines of force cut the coil so
placed. It does not follow, therefore, that the center of the magnet is
its strongest part, as the results of the experiments at first sight
appear to show.

It was while engaged on those experiments that I discovered that a
telephone was affected when not in any way connected with the spiral,
but simply placed so that the lines of force proceeding from the spiral
impinged upon the iron diaphragm of the telephone. Please to bear in
mind that the direction of the lines of force emitted from the spiral
is such that, starting from any point on one of its faces, a circle
is described extending to a similar point on the opposite side. The
diameter of the circles described decreases from infinity as the points
from which they start recede from the center toward the circumference.
From points near the circumference these circles or curves are very
small. To illustrate this to you, the reverser now in circuit with
spiral C will be replaced by a simple make and break arrangement,
consisting on a small electro-magnet fixed between the prongs of a
tuning-fork, and so connected that electro-magnet influences the arms of
the fork, causing them to vibrate to a certain pitch. The apparatus is
placed in a distant room to prevent the sound being heard here, as I
wish to make it inductively audible to you. For that purpose I have here
a light spiral which is in circuit with this telephone. Now, by placing
the spiral in front of spiral C, the telephone reproduces the sound
given out by the tuning-fork so loudly that I have no doubt all of you
can hear it. Here is another spiral similar in every respect to spiral
C. This is in circuit with a battery and an ordinary mechanical make and
break arrangement, the sound given off by which I will now make audible
to you in the same way that I did the sound of the tuning-fork. Now you
hear it. I will change from the one spiral to the other several times,
as I want to make you acquainted with the sounds of both, so that you
will have no difficulty in distinguishing them, the one from the other.

There are suspended in this room self-luminous bodies which enable us by
their rays or lines of force to see the non-luminous bodies with which
we are surrounded. There are also radiating in all directions from me
while speaking lines of force or sound waves which affect more or
less each one of you. But there are also in addition to, and quite
independent of, the lines of force just mentioned, magnetic lines
of force which are too subtle to be recognized by human beings,
consequently, figuratively, we are both blind and deaf to them. However,
they can be made manifest either by their notion on a suspended magnet
or on a conducting body moving across them; the former showing its
results by attraction and repulsion, the latter by the production of an
electric current. For instance, by connecting the small flat spiral of
copper wire in direct circuit with the galvanometer, you will perceive
that the slightest movement of the spiral generates a current of
sufficient strength to very sensibly affect the galvanometer; and as
you observe, the amplitude of the deflection depends upon the speed
and direction in which the spiral is moved. We know that by moving a
conductor of electricity in a magnetic field we are able to produce an
electric current of sufficient intensity to produce light resembling
in all its phases that of solar light; but to produce these strong
currents, very powerful artificial magnetic fields have to be generated,
and the conductor has to be moved therein at a great expenditure of heat
energy. May not the time arrive when we shall no longer require these
artificial and costly means, but have learned how to adopt those forces
of nature which we now so much neglect? One ampere of current passing
through an ordinary incandescent lamp will produce a light equal to ten
candles, and I have shown that by simply moving this small flat spiral a
current is induced in it from the earth's magnetic field equal to 0.0007
ampere. With these facts before us, surely it would not be boldness to
predict that a time may arrive when the energy of the wind or tide will
be employed to produce from the magnetic lines of force given out by the
earth's magnetism electrical currents far surpassing anything we have
yet seen or of which we have heard. Therefore let us not despise the
smallness of the force, but rather consider it an element of power from
which might arise conditions far higher in degree, and which we might
not recognize as the same as this developed in its incipient stage.

If the galvanometer be replaced by a telephone, no matter how the spiral
be moved, no sound will be heard, simply because the induced currents
produced consist of comparatively slow undulations, and not of sharp
variations suitable for a telephone. But by placing in circuit this
mechanical make and break arrangement the interruptions of the current
are at once audible, and by regulating the movement of the spiral I can
send signals, which, if they had been prearranged, might have enabled
us to communicate intelligence to each other by means of the earth's
magnetism. I show this experiment more with a view to illustrate the
fact that for experiments on induction both instruments are necessary,
as each makes manifest those currents adapted to itself.

The lines of force of light, heat, and sound can be artificially
produced and intensified, and the more intense--they are the more we
perceive their effects on our eyes, ears, or bodies. But it is not so
with the lines of magnetic force, for it matters not how much their
power is increased--they appear in no way to affect us. Their presence
can, however, be made manifest to our eyes or ears by mechanical
appliances. I have already shown you how this can be done by means of
either a galvanometer or a telephone in circuit with a spiral wire.

I have already stated that while engaged in these experiments I found
that as far as the telephone was concerned it was immaterial whether it
was in circuit with a spiral or not, as in either case it accurately
reproduced the same sounds; therefore, much in the same way as lenses
assist the sight or tubes the hearing, so does the telephone make
manifest the lines of intermittent inductive energy. This was quite a
new phenomenon to me, and on further investigation of the subject I
found that it was not necessary to have even a telephone, for by simply
holding a piece of iron to my ear and placing it close to the center
of the spiral I could distinctly hear the same sounds as with the
telephone, although not so loud. The intensity of the sound was greatly
increased when the iron was placed in a magnetic field. Here is a small
disk of iron similar to those used in telephones, firmly secured in this
brass frame; this is a small permanent bar magnet, the marked end of
which is fixed very closely to, but not touching, the center of the iron
disk. Now, by applying the disk to my ear I can hear the same sounds
that were audible to all of you when the telephone in circuit with a
small spiral was placed in front of and close to the large spiral. To me
the sound is quite as loud as when you heard it; but now you are one and
all totally deaf to it. My original object in constructing two large
spirals was to ascertain whether the inductive lines of force given out
from one source would in any way interfere with those proceeding from
another source. By the aid of this simple iron disk and magnet it can be
ascertained that they do in no way interfere with each other; therefore,
the direction of the lines proceeding from each spiral can be distinctly
traced. For when the two spirals are placed parallel to each other at
a distance of 3 ft. apart, and connected to independent batteries and
transmitters, as shown in Plate 7, each transmitter having a sound
perfectly distinct from that of the other, when the circuits are
completed the separate sounds given out by the two transmitters can be
distinctly heard at the same time by the aid of a telephone; but, by
placing the telephone in a position neutral to one of the spirals, then
only the sound proceeding from the other can be heard. These results
occur in whatever position the spirals are placed relatively to each
other, thus proving that there is no interference with or blending of
the separate lines of force. The whole arrangement will be left in
working order at the close of the meeting for any gentlemen present to
verify my statements or to make what experiments they please.

In conclusion, I would ask, what can we as practical men gather from
these experiments? A great deal has been written and said as to the best
means to secure conductors carrying currents of very low tension,
such as telephone circuits, from being influenced by induction from
conductors in their immediate vicinity employed in carrying currents of
comparatively very high tension, such as the ordinary telegraph wires.
Covering the insulated wires with one or other of the various metals has
not only been suggested but said to have been actually employed with
marked success. Now, it will found that a thin sheet of any known metal
will in no appreciable way interrupt the inductive lines of force
passing between two flat spirals; that being so, it is difficult to
understand how inductive effects are influenced by a metal covering as
described.

Telegraph engineers and electricians have done much toward accomplishing
the successful working of our present railway system, but still there
is much scope for improvements in the signaling arrangements. In foggy
weather the system now adopted is comparatively useless, and resource
has to be had at such times to the dangerous and somewhat clumsy method
of signaling by means of detonating charges placed upon the rails.
Now, it has occurred to me that volta induction might be employed with
advantage in various ways for signaling purposes. For example, one or
more wire spirals could be fixed between the rails at any convenient
distance from the signaling station, so that when necessary intermittent
currents could be sent through the spirals; and another spiral could be
fixed beneath the engine or guard's van, and connected to one or more
telephones placed near those in charge of the train. Then as the train
passed over the fixed spiral the sound given out by the transmitter
would be loudly reproduced by the telephone and indicate by its
character the signal intended.

One of my experiments in this direction will perhaps better illustrate
my meaning. The large spiral was connected in circuit with twelve
Leclanche cells and the two make and break transmitters before
described. They were so connected that either transmitter could be
switched into circuit when required, and this I considered the signaling
station. This small spiral was so arranged that it passed in front of
the large one at the distance of 8 in. and at a speed of twenty-eight
miles per hour. The terminals of the small spiral were connected to
a telephone fixed in a distant room, the result being that the sound
reproduced from either transmitter could be clearly heard and recognized
every time the spirals passed each other. With a knowledge of this fact
I think it will be readily understood now a cheap and efficient adjunct
to the present system of railway signaling could be obtained by such
means as I have ventured to bring to your notice this evening.

Thus have I given you some of the thoughts and experiments which have
occupied my attention during my leisure. I have been long under the
impression that there is a feeling in the minds of many that we are
already in a position to give an answer to almost every question
relating to electricity or magnetism. All I can say is, that the more
I endeavor to advance in a knowledge of these subjects, the more am I
convinced of the fallacy of such a position. There is much yet to be
learnt, and if there be present either member, associate, or student to
whom I have imparted the smallest instruction, I shall feel that I have
not unprofitably occupied my time this evening.

       *       *       *       *       *




ON TELPHERAGE.

[Footnote: Introductory address delivered to the Class of Engineering,
University of Edinburgh, October 30, 1883.]

By Professor FLEEMING JENKIN, LL.D., F.R.S.


"The transmission of vehicles by electricity to a distance,
independently of any control exercised from the vehicle, I will call
Telpherage." These words are quoted from my first patent relating to
this subject. The word should, by the ordinary rules of derivation, be
telphorage; but as this word sounds badly to my ear, I ventured to adopt
such a modified form as constant usage in England for a few centuries
might have produced, and I was the more ready to trust to my ear in the
matter because the word telpher relieves us from the confusion which
might arise between telephore and telephone, when written.

I have been encouraged to choose Telpherage as the subject of my address
by the fact that a public exhibition of a telpher line, with trains
running on it, will be made this afternoon for the first time.

You are, of course, all aware that electrical railways have been run,
and are running with success in several places. Their introduction has
been chiefly due to the energy and invention of Messrs. Siemens. I do
not doubt of their success and great extension in the future--but when
considering the earliest examples of these railways in the spring of
last year, it occurred to me that in simply adapting electric motors to
the old form of railway and rolling stock, inventors had not gone far
enough back. George Stephenson said that the railway and locomotive were
two parts of one machine, and the inference seemed to follow that when
electric motors were to be employed a new form of road and a new type of
train would be desirable.

When using steam, we can produce the power most economically in large
engines, and we can control the power most effectually and most cheaply
when so produced. A separate steam engine to each carriage, with its own
stoker and driver, could not compete with the large locomotive and heavy
train; but these imply a strong and costly road and permanent way. No
mechanical method of distributing power, so as to pull trains along at a
distance from a stationary engine, has been successful on our railways;
but now that electricity has given us new and unrivaled means for the
distribution of power, the problem requires reconsideration.

With the help of an electric current as the transmitter of power, we
can draw off, as it were, one, two, or three horse-power from a hundred
different points of a conductor many miles long, with as much ease as we
can obtain 100 or 200 horse-power at any one point. We can cut off the
power from any single motor by the mere break of contact between two
pieces of metal; we can restore the power by merely letting the two
pieces of metal touch; we can make these changes by electro magnets with
the rapidity of thought, and we can deal as we please with each of
one hundred motors without sensibly affecting the others. These
considerations led me to conclude, in the first place, that when using
electricity we might with advantage subdivide the weight to be carried,
distributing the load among many light vehicles following each other in
an almost continuous stream, instead of concentrating the load in heavy
trains widely spaced, as in our actual railways. The change in the
distribution of the load would allow us to adopt a cheap, light form
of load. The wide distribution of weight, entails many small trains in
substitution for a single heavy train; these small trains could not be
economically run if a separate driver were required for each. But, as
I have already pointed out, electricity not only facilitates the
distribution of power, but gives a ready means of controlling that
power. Our light, continuous stream of trains can, therefore, be
worked automatically, or managed independently of any guard or driver
accompanying the train--in other words, I could arrange a self-acting
block for preventing collisions. Next came the question, what would be
the best form of substructure for the new mode of conveyance? Suspended
rods or ropes, at a considerable height, appeared to me to have great
advantages over any road on the level of the ground; the suspended rods
also seemed superior to any stiff form of rail or girder supported at a
height. The insulation of ropes with few supports would be easy; they
could cross the country with no bridges or earth-works; they would
remove the electrical conductor to a safe distance from men and cattle;
cheap small rods employed as so many light suspension bridges would
support in the aggregate a large weight. Moreover, I consider that a
single rod or rail would present great advantages over any double rail
system, provided any suitable means could be devised for driving a train
along a single track. (Up to that time two conductors had invariably
been used.) It also seemed desirable that the metal rod bearing the
train should also convey the current driving it. Lines such as I
contemplated would not impede cultivation nor interfere with fencing.
Ground need not be purchased for their erection. Mere wayleaves would
be sufficient, as in the case of telegraphs. My ideas had reached this
point in the spring of 1882, and I had devised some means for carrying
them into effect when I read the account of the electrical railway
exhibited by Professors Ayrton and Perry. In connection with this
railway they had contrived means rendering the control of the vehicles
independent of the action of the guard or driver; and this absolute
block, as they called their system, seemed to me all that was required
to enable me at once to carry out my idea of a continuous stream of
light, evenly spaced trains, with no drivers or guards. I saw, moreover,
that the development of the system I had in view would be a severe tax
on my time and energy; also that in Edinburgh I was not well placed for
pushing such a scheme, and I had formed a high opinion of the value of
the assistance which Professors Ayrton and Perry could give in designs
and inventions.

Moved by these considerations, I wrote asking Professor Ayrton to
co-operate in the development of my scheme, and suggesting that he
should join with me in taking out my first Telpher patent. It has been
found more convenient to keep our several patents distinct, but my
letter ultimately led to the formation of the Telpherage Company
(limited), in which Professor Ayrton, Professor Perry, and I have equal
interests. This company owns all our inventions in respect of electric
locomotion, and the line shown in action to-day has been erected by this
company on the estate of the chairman--Mr. Marlborough R. Pryor, of
Weston. Since the summer of last year, and more especially since the
formation of the company this spring, much time and thought has been
spent in elaborating details. We are still far from the end of our work,
and it is highly probable what has been done will change rapidly by a
natural process of evolution. Nevertheless, the actual line now working
does in all its main features accurately reproduce my first conception,
and the general principles I have just laid down will, I think, remain
true, however great the change in details may be.

The line at Weston consist of a series of posts, 60 ft. apart, with two
lines of rods or ropes, supported by crossheads on the posts. Each of
these lines carries a train; one in fact is the up line, and the other
the down line. Square steel rods, round steel rods, and steel wire ropes
are all in course of trial. The round steel rod is my favorite road at
present. The line is divided into sections of 120 ft. or two spans, and
each section is insulated from its neighbor. The rod or rope is at the
post supported by cast-iron saddles, curved in a vertical plane, so as
to facilitate the passage of the wheels over the point of support.
Each alternate section is insulated from the ground; all the insulated
sections are in electrical connection with one another--so are all the
uninsulated sections. The train is 120 ft. long--the same length as that
of a section. It consists of a series of seven buckets and a locomotive,
evenly spaced with ash distance pieces--each bucket will convey, as a
useful load, about 2½ cwt., and the bucket or skep, as it has come to be
called, weighs, with its load, about 3 cwt. The locomotive also weighs
about 3 cwt. The skeps hang below the line from one or from two V
wheels, supported by arms which project out sideways so as to clear the
supports at the posts; the motor or dynamo on the locomotive is also
below the line. It is supported on two broad flat wheels, and is driven
by two horizontal gripping wheels; the connection of these with the
motor is made by a new kind of frictional gear which I have called nest
gear, but which I cannot describe to-day. The motor on the locomotive
as a maximum 1½ horse-power when so much is needed. A wire connects one
pole of the motor with the leading wheel of the train, and a second wire
connects the other pole with the trailing wheel; the other wheels are
insulated from each other. Thus the train, wherever it stands, bridges a
gap separating the insulated from the uninsulated section. The insulated
sections are supplied with electricity from a dynamo driven by a
stationary engine, and the current passing from the insulated section
to the uninsulated section through the motor drives the locomotive. The
actual line is quite short, and can only show two trains, one on the up
and one on the down line; but with sufficient power at the station any
number of trains could be driven in a continuous stream on each line.
The appearance is that of a line of buckets running along a single
telegraph wire of large size. A block system is devised and partly made,
but is not yet erected. It differs from the earlier proposals in having
no working parts on the line. This system of propulsion is called by us
the Cross Over Parallel Arc. Other systems of supplying the currents,
devised both by Professors Ayrton and Perry and myself, will be tried on
lines now being erected; but that just described gives good results. The
motors employed in the locomotives were invented by Messrs. Ayrton and
Perry. They are believed to have the special advantage of giving a
larger power for a given weight than any others. One weighing 99 lb.
gave 1½ horse-power in some tests lately made. One weighing 36 lb. gave
0.41 horse-power.

No scientific experiments have yet been made on the working of the line,
and matters are not yet ripe for this--but we know that we can erect a
cheap and simple permanent way, which will convey a useful load of say
15 cwt. on every alternate span of 130 feet. This corresponds to 16½
tons per mile, which, running at five miles per hour, would convey 92½
tons of goods per hour. Thus if we work for 20 hours, the line will
convey 1850 tons of goods each way per diem, which seems a very fair
performance for an inch rope. The arrangement of the line with only one
rod instead of two rails diminishes friction very greatly. The carriages
run as light as bicycles. The same peculiarity allows very sharp curves
to be taken, but I am without experimental tests as yet of the limit
in this respect. Further, we now know that we can insulate the line
satisfactorily, even if very high potentials come to be employed. The
grip of the locomotive is admirable and almost frictionless, the gear is
silent and runs very easily. It is suited for the highest speeds, and
this is very necessary, as the motors may with advantage, run at 2,000
revolutions per minute.

       *       *       *       *       *




MACHINE FOR MAKING ELECTRIC LIGHT CARBONS.


One of the hinderances to the production of a regular and steady light
in electric illumination is the absence of perfect uniformity in the
carbons. This defect has more than once been pointed out by us, and we
are glad to notice any attempt to remedy an admitted evil. To this end
we illustrate above a machine for manufacturing carbons, invented by
William Cunliffe. The object the inventor has in view is not only the
better but the more rapid manufacture of carbons, candles, or electrodes
for electric lighting or for the manufacture of rods or blocks of carbon
or other compressible substances for other purposes, and his invention
consists in automatic machinery whereby a regular and uniform pressure
and compression of the carbon is obtained, and the rods or blocks are
delivered through the formers, in a state of greater density and better
quality then hitherto. The machine consists of two cylinders, A A',
placed longitudinally, as shown at Fig. 1, and in reversed position in
relation to each other. In each cylinder works a piston or plunger, a,
with a connecting rod or rods, b; in the latter case the ends of the
rods have right and left handed threads upon which a sleeve, c, with
corresponding threads, works. This sleeve, c, is provided with a hand
wheel, so that by the turning it the stroke of the plungers, a a, and
the size of the chambers, A A', is regulated so that the quantity of
material to be passed through the dies or formers is thereby determined
and may be indicated. In front of the chambers, A A', are fixed the dies
or formers, d d, which may have any number of perforations of the size
or shape of the carbon it is intended to mould. The dies are held in
position by clamp pieces, e e, secured to the end of the chambers A
A', by screws, and on each side of these clamp pieces are guides, with
grooves, in which moves a bar with a crosshead, termed the guillotine,
and which moves across the openings of the dies, and opening or closing
them. Near the front end of the cylinders are placed small pistons or
valves, f f, kept down in position by the weighted levers, g g (see Fig.
2, which is drawn to an enlarged scale), which, when the pressure in
the chamber exceeds that of the weighted levers connected to the safety
valve, f, the latter is raised and the guillotine bar, h, moved across
the openings of the dies by the connecting rods, h', thereby allowing
the carbon to be forced through the dies. In the backward movement
of the piston, a, a fresh supply of material is drawn by atmospheric
pressure through the hoppers, B B', alternately. At the end of the
stroke the arms of the rocking levers (which are connected by tension
rods with the tappet levers) are struck by the disk wheel or regulator,
the guillotine is moved back and replaced over the openings of the
dies, ready for the next charge, as shown. The plungers are operated by
hydraulic, steam, compressed air, or other power, the inlet and outlet
of such a pressure being regulated by a valve, an example of which is
shown at Fig. 1, and provided with the tappet levers, i i, hinged to the
valve chest, C, as shown, and attached to spindles, i' i', operating the
slide valves, and struck alternately at the end of each stroke, thus
operating the valves and the guillotine connections, i² and i³. The
front ends of the cylinders may be placed at an angle for the more
convenient delivery of the moulded articles.--_Iron_.

[Illustration: MACHINE FOR MAKING ELECTRIC LIGHT CARBONS]

       *       *       *       *       *




NEW ELECTRIC BATTERY LIGHTS.


There has lately been held, at No. 31 Lombard Street, London, a private
exhibition of the Holmes and Burke primary galvanic battery. The chief
object of the display was to demonstrate its suitability for the
lighting of railway trains, but at the same time means were provided
to show it in connection with ordinary domestic illumination, as it is
evident that a battery will serve equally as well for the latter as for
the former purpose. Already the great Northern express leaving London at
5:30 P.M. is lighted by this means, and satisfactory experiments have
been made upon the South-western line, while the inventors give a long
list of other companies to which experimental plant is to be supplied.
The battery shown, in Lombard Street consisted of fifteen cells arranged
in three boxes of five cells each. Each box measured about 18 in. by
12 in. by 10 in., and weighed from 75 lb. to 100 lb. The electromotive
force of each cell was 1.8 volts and its internal resistance from 1/40
to 1/50 of an ohm, consequently the battery exhibited had, under the
must favorable circumstances, a difference of potential of 27 volts at
its poles, and a resistance of 0.3 ohm.

When connected to a group of ten Swan lamps of five candle power,
requiring a difference of potential of 20 volts, it raised them to vivid
incandescence, considerably above their nominal capacity, but it failed
to supply eighteen lamps of the same kind satisfactorily, showing that
its working capacity lay somewhere between the two. A more powerful lamp
is used in the railway carriages, but as there was only one erected it
was impossible to judge of the number that a battery of the size shown
would feed. _Engineering_ says the trial, however, demonstrated that
great quantities of current were being continuously evolved, and if,
as we understood, the production can be maintained constant for about
twenty-four hours without attention, the new battery marks a distinct
step in this kind of electric lighting. Of the construction of the
battery we unfortunately can say but little, as the patents are not yet
completed, but we may state that the solid elements are zinc and
carbon, and that the novelty lies in the liquid, and in the ingenious
arrangement for supplying and withdrawing it.

Ordinarily one charge of liquid will serve for twenty-four hours
working, but this, of course, is entirely determined by the space
provided for it. It is sold at sevenpence a gallon, and each gallon is
sufficient, we are informed, to drive a cell while it generates 800
ampere hours of current, or, taking the electromotive force at 1.8
volts, it represents (800 x 1.8) / 746 = 1.93 horse-power hours. The
cost of the zinc is stated to be 35 per cent. of that of the fluid,
although it is difficult to see how this can be, for one horse-power
requires the consumption of 895.2 grammes of zinc per hour, or 1.96 lb.,
and this at 18_l_. per ton, would cost 1.93 pence per pound, or 3.8
pence per horse-power hour. This added to 3.6 pence for the fluid, would
give a total of 7.4 pence per horse-power per hour, and assuming twenty
lamps of ten candle power to be fed per horse-power, the cost would be
about one-third of a penny per hour per lamp.

Mr Holmes admits his statement of the consumption of zinc does not agree
with what might be theoretically expected but he bases it upon the
result of his experiments in the Pullman train, which place the cost at
one farthing per hour per light. At the same time he does not profess
that the battery can compete in the matter of cost with mechanically
generated currents on a large scale, but he offers it as a convenient
means of obtaining the electric light in places where a steam engine or
a gas engine is inadmissible, as in a private house, and where the cost
of driving a dynamo machine is raised abnormally high by reason of a
special attendant having to be paid to look after it.

But he has another scheme for the reduction of the cost, to which we
have not yet alluded, and of which we can say but little, as the details
are not at present available for publication. The battery gives off
fumes which can be condensed into a nitrogenous substance, valuable, it
is stated, as a manure, while the zinc salts in the spent liquid can be
recovered and returned to useful purposes. How far this is practicable
it is at present impossible to say, but at any rate the idea represents
a step in the right direction, and if the electricians can follow the
example of the gas manufacturers and obtain a revenue from the residuals
of galvanic batteries, they will greatly improve their commercial
position. There is nothing impossible in the idea, and neither is it
altogether novel, although the way of carrying it out may be. In 1848,
Staite, one of the early enthusiasts in electric lighting, patented a
series of batteries from which he proposed to recover sulphate, nitrate,
and chloride of zinc, but we never heard that he obtained any success.

       *       *       *       *       *




NEW ELECTRIC RAILWAY.


The original electric railway laid down by Messrs. Siemens and Halske
at Berlin seems likely to be the parent of many others. One of the most
recent is the underground electric line laid down by the firm in the
mines of Zankerodain Saxony. An account of this railway has appeared in
_Glaser's Annalen_, together with drawings of the engine, which we are
able to reproduce. They are derived from a paper by Herr Fischer, read
on the 19th December, 1882, before the Electro-Technical Union of
Germany. The line in question is 700 meters long--770 yards--and has two
lines of way. It lies 270 meters--300 yards--below the surface of the
ground. It is worked by an electric locomotive, hauling ten wagons at a
speed of 12 kilometers, or 7½ miles per hour. The total weight drawn is
eight tons. The gauge is a narrow one, so that the locomotive can be
made of small dimensions. Its total length between the buffer heads is
2.43 meters; its height 1.04 meters; breadth 0.8 meter; diameter of
wheels, 0.34 meter. From the rail head to the center of the buffers is a
height of 0.675 meter; and the total weight is only 1550 kilogrammes, or
say 3,400 lb. We give a longitudinal section through the locomotive. It
will be seen that there is a seat at each end for the driver, so that he
can always look forwards, whichever way the engine may be running. The
arrangements for connection with the electric current are very simple.
The current is generated by a dynamo machine fixed outside the mine, and
run by a small rotary steam engine, shown in section and elevation, at a
speed of 900 revolutions per minute. The current passes through a cable
down the shaft to a T-iron fixed to the side of the heading. On this
T-iron slide contact pieces which are connected with the electric engine
by leading wires. The driver by turning a handle can move his engine
backward or forward at will. The whole arrangement has worked extremely
well, and it is stated that the locomotive, if so arranged, could easily
do double its present work; in other words, could haul 15 to 16 tons of
train load at a speed of seven miles an hour. The arrangements for the
dynamo machine on the engine, and its connection with the wheels, are
much the same as those used in Sir William Siemens' electric railway now
working near the Giant's Causeway.--_The Engineer_.

[Illustration: THE SIEMENS ELECTRIC RAILWAY AT ZANKERODA MINES.]

       *       *       *       *       *




THE EARLIEST GAS-ENGINE.


Lebon, in the certificate dated 1801, in addition to his first patent,
described and illustrated a three-cylinder gas-engine in which an
explosive mixture of gas and air was to have been ignited by an electric
spark. This is a curious anticipation of the Lenior system, not brought
out until more than fifty years later; but there is no evidence that
Lebon ever constructed an engine after the design referred to. It is an
instructive lesson to would-be patentees, who frequently expect to reap
immediate fame and fortune from their property in some crude ideas which
they fondly deem to be an "invention," to observe the very wide interval
that separates Lebon from Otto. The idea is the same in both cases; but
it has required long years of patient work, and many failures, to embody
the idea in a suitable form. It is almost surprising, to any one who has
not specially studied the matter, to discover the number of devices
that have been tried with the object of making an explosion engine, as
distinguished from one deriving its motive power from the expansion of
gaseous fluids. A narrative of some of these attempts has been presented
to the Societe des Ingenieurs Civils; mostly taken in the first place
from Stuart's work upon the origin of the steam engine, published in
1820, and now somewhat scarce. It appears from this statement that so
long ago as 1794, Robert Street described and patented an engine in
winch the piston was to be driven by the explosion of a gaseous mixture
whereof the combustible element was furnished by the vaporization of
_terebenthine_ (turpentine) thrown upon red hot iron. In 1807 De Rivaz
applied the same idea in a different manner. He employed a cylinder
12 centimeters in diameter fitted with a piston. At the bottom of the
cylinder there was another smaller one, also provided with a piston.
This was the aspirating cylinder, which drew hydrogen from an inflated
bag, and mixed it with twice its bulk of air by means of a two-way cock.
The ignition of the detonating mixture was effected by an electric
spark. It is said that the inventor applied his apparatus to a small
locomotive.

In 1820 Mr. Cecil, of Cambridge, proposed the employment of a mixture of
air and hydrogen as a source of motive power; he gave a detailed account
of his invention in the _Transactions_ of the Cambridge Philosophical
Society, together with some interesting theoretical considerations.
The author observes here that an explosion may be safely opposed by
an elastic resistance--that of compressed air, for example--if such
resistance possesses little or no inertia to be brought into play;
contrariwise, the smallest inertia opposed to the explosion of a mixture
subjected to instantaneous combustion is equivalent to an insurmountable
obstacle. Thus a small quantity of gunpowder, or a detonating mixture of
air and hydrogen, may without danger be ignited in a large closed vessel
full of air, because the pressure against the sides of the vessel
exerted by the explosion is not more than the pressure of the air
compressed by the explosion. If a piece of card board, or even of paper,
is placed in the middle of the bore of a cannon charged with powder, the
cannon will almost certainly burst, because the powder in detonating
acts upon a body in repose which can only be put in motion in a period
of time infinitely little by the intervention of a force infinitely
great. The piece of paper is therefore equivalent to an insurmountable
obstacle. Of all detonating mixtures, or explosive materials, the most
dangerous for equal expansions, and the least fitted for use as motive
power, are those which inflame the most rapidly. Thus, a mixture
of oxygen and hydrogen, in which the inflammation is produced
instantaneously, is less convenient for this particular usage than a
mixture of air and hydrogen, which inflames more slowly. From this point
of view, ordinary gunpowder would make a good source of motive
power, because, notwithstanding its great power of dilatation, it is
comparatively slow of ignition; only it would be necessary to take
particular precautions to place the moving body in close contact with
the powder. Cecil pointed out that while a small steam engine could not
be started in work in less than half an hour, or probably more, a gas
engine such as he proposed would have the advantage of being always
ready for immediate use. Cecil's engine was the first in which the
explosive mixture was ignited by a simple flame of gas drawn into the
cylinder at the right moment. In the first model, which was that of
a vertical beam engine with a long cylinder of comparatively small
diameter, the motive power was simply derived from the descent of the
piston by atmospheric pressure; but Mr. Cecil is careful to state that
power may also be obtained directly from the force of the explosion. The
engine was worked with a cylinder pressure of about 12 atmospheres, and
the inventor seems to have recognized that the noise of the explosions
might be an objection to the machine, for he suggests putting the end of
the cylinder down in a well, or inclosing it in a tight vessel for the
purpose of deadening the shock.

It is interesting to rescue for a moment the account of Mr. Cecil's
invention from the obscurity into which it has fallen--obscurity which
the ingenuity of the ideas embodied in this machine does not merit. It
is probable that in addition to the imperfections of his machinery,
Mr. Cecil suffered from the difficulty of obtaining hydrogen at a
sufficiently low price for use in large quantities. It does not
transpire that the inventor ever seriously turned his attention to the
advantages of coal gas, which even at that time, although very dear,
must have been much cheaper than hydrogen. Knowing what we do at
present, however, of the consumption of gas by a good engine of the
latest pattern, it may be assumed that a great deal of the trouble of
the gas engine builders of 60 years ago arose from the simple fact of
their being altogether before their age. Of course, the steam engine of
1820 was a much more wasteful machine, as well as more costly to build
than the steam engine of to-day; but the difference cannot have been so
great as to create an advantage in favor of an appliance which required
even greater nicety of construction. The best gas-engine at present made
would have been an expensive thing to supply with gas at the prices
current in 1820, even if the resources of mechanical science at that
date had been equal to its construction; which we know was not the case.
Still, this consideration was not known, or was little valued, by Mr.
Cecil and his contemporaries. It was not long, however, before Mr. Cecil
had to give way before a formidable rival; for in 1823 Samuel Brown
brought out his engine, which was in many respects an improvement upon
the one already described. It will probably be right, however, to regard
the Rev. Mr. Cecil, of Cambridge, as the first to make a practicable
model of a gas-engine in the United Kingdom.--_Journal of Gas Lighting_.

       *       *       *       *       *

Alabama has 2,118 factories, working 8,248 hands, with a capital
invested of $5,714,032, paying annually in wages $2,227,968, and
yielding annually in products $13,040,644.

       *       *       *       *       *




THE MOVING OF LARGE MASSES.

[Footnote: For previous article see SUPPLEMENT 367.]


The moving of a belfry was effected in 1776 by a mason who knew neither
how to read nor write. This structure was, and still is, at Crescentino,
upon the left bank of the Po, between Turin and Cazal. The following is
the official report on the operation:

"In the year 1776, on the second day of September, the ordinary council
was convoked, ... as it is well known that, on the 26th of May last,
there was effected the removal of a belfry, 7 trabucs (22.5 m.) or
more in height, from the church called _Madonna del Palazzo_, with the
concurrence and in the presence and amid the applause of numerous people
of this city and of strangers who had come in order to be witnesses of
the removal of the said tower with its base and entire form, by means of
the processes of our fellow-citizen Serra, a master mason who took it
upon himself to move the said belfry to a distance of 3 meters, and to
annex it to a church in course of construction. In order to effect this
removal, the four faces of the brick walls were first cut and opened at
the base of the tower and on a level with the earth. Into the apertures
from north to south, that is to say in the direction that the edifice
was to take, there were introduced two large beams, and with these there
ran parallel, external to the belfry and alongside of it, two other rows
of beams of sufficient length and extent to form for the structure a bed
over which it might be moved and placed in position in the new spot,
where foundations of brick and lime had previously been prepared.

[Illustration: FIG. 1.--REMOVAL OF A BELFRY AT CRESCENTINO IN 1776]

"Upon this plane there were afterward placed rollers 3½ inches in
diameter, and, upon these latter, there was placed a second row of beams
of the same length as the others. Into the eastern and western apertures
there were inserted, in cross-form, two beams of less length.

"In order to prevent the oscillation of the tower, the latter was
supported by eight joists, two of these being placed on each side and
joined at their bases, each with one of the four beams, and, at their
apices, with the walls of the tower at about two-thirds of its height.

"The plane over which the edifice was to be rolled had an inclination of
one inch. The belfry was hauled by three cables that wound around
three capstans, each of which was actuated by ten men. The removal was
effected in less than an hour.

"It should be remarked that during the operation the son of the mason
Serra, standing in the belfry, continued to ring peals, the bells not
having been taken out.

"Done at Crescentino, in the year and on the day mentioned."

A note communicated to the Academie des Sciences at its session of May
9, 1831, added that the base of the belfry was 3.3 m. square. This
permits us to estimate its weight at about 150 tons.

[Illustration: FIG. 2.--MOVING THE WINGED BULLS FROM NINEVEH TO MOSUL IN
1854]

Fig. 1 shows the general aspect of the belfry with its stays. This is
taken from an engraving published in 1844 by Mr. De Gregori, who, during
his childhood, was a witness of the operation, and who endeavored to
render the information given by the official account completer without
being able to make the process much clearer.

In 1854 Mr. Victor Place moved overland, from Nineveh to Mosul, the
winged bulls that at present are in the Assyrian museum of the Louvre,
and each of which weighs 32 tons. After carefully packing these in boxes
in order to preserve them from shocks, Place laid them upon their side,
having turned them over, by means of levers, against a sloping bank of
earth That he afterward dug away in such a manner that the operation was
performed without accident. He had had constructed an enormous car with
axles 0.25 m. in diameter, and solid wheels 0.8 m. in thickness (Fig.
2). Beneath the center of the box containing the bull a trench was dug
that ran up to the natural lever of the soil by an incline. This trench
had a depth and width such that the car could run under the box while
the latter was supported at two of its extremities by the banks. These
latter were afterward gradually cut away until the box rested upon the
car without shock. Six hundred men then manned the ropes and hauled the
car with its load up to the level of the plain. These six hundred men
were necessary throughout nearly the entire route over a plain that
was but slightly broken and in which the ground presented but little
consistency.

The route from Khorsabad to Mosul was about 18 kilometers, taking into
account all the detours that had to be made in order to have a somewhat
firm roadway. It took four days to transport the first bull this
distance, but it required only a day and a half to move the other one,
since the ground had acquired more compactness as a consequence of
moving the first one over it, and since the leaders had become more
expert. The six hundred men at Mr. Place's disposal had, moreover, been
employed for three months back in preparing the route, in strengthening
it with piles in certain spots and in paving others with flagstones
brought from the ruins of Nineveh. In a succeeding article I shall
describe how I, a few years ago, moved an ammunition stone house,
weighing 50 tons, to a distance of 35 meters without any other machine
than a capstan actuated by two men.--_A. De Rochas, in La Nature_.

       *       *       *       *       *

[NATURE.]




SCIENCE AND ENGINEERING.


In the address delivered by Mr. Westmacott, President of the Institution
of Mechanical Engineers to the English and Belgian engineers assembled
at Liege last August, there occurred the following passage: "Engineering
brings all other sciences into play; chemical or physical discoveries,
such as those of Faraday, would be of little practical use if engineers
were not ready with mechanical appliances to carry them out, and make
them commercially successful in the way best suited to each."

We have no objection to make to these words, spoken at such a time and
before such an assembly. It would of course be easy to take the converse
view, and observe that engineering would have made little progress in
modern times, but for the splendid resources which the discoveries of
pure science have placed at her disposal, and which she has only had to
adopt and utilize for her own purposes. But there is no need to quarrel
over two opposite modes of stating the same fact. There _is_ need on
the other hand that the fact itself should be fairly recognized and
accepted, namely, that science may be looked upon as at once the
handmaid and the guide of art, art as at once the pupil and the
supporter of science. In the present article we propose to give a few
illustrations which will bring out and emphasize this truth.

We could scarcely find a better instance than is furnished to our hand
in the sentence we have chosen for a text. No man ever worked with a
more single hearted devotion to pure science--with a more absolute
disregard of money or fame, as compared with knowledge--than Michael
Faraday. Yet future ages will perhaps judge that no stronger impulse was
ever given to the progress of industrial art, or to the advancement of
the material interests of mankind, than the impulse which sprang from
his discoveries in electricity and magnetism. Of these discoveries
we are only now beginning to reap the benefit. But we have merely to
consider the position which the dynamo-electric machine already occupies
in the industrial world, and the far higher position, which, as almost
all admit, it is destined to occupy in the future, in order to see
how much we owe to Faraday's establishment of the connection between
magnetism and electricity. That is one side of the question--the debt
which art owes to science. But let us look at the other side also. Does
science owe nothing to art? Will any one say that we should know as much
as we do concerning the theory of the dynamo-electric motor, and the
laws of electro-magnetic action generally, if that motor had never
risen (or fallen, as you choose to put it) to be something besides the
instrument of a laboratory, or the toy of a lecture room? Only a short
time since the illustrious French physicist, M. Tresca, was enumerating
the various sources of loss in the transmission of power by electricity
along a fixed wire, as elucidated in the careful and elaborate
experiments inaugurated by M. Marcel Deprez, and subsequently continued
by himself. These losses--the electrical no less than the mechanical
losses--are being thoroughly and minutely examined in the hope of
reducing them to the lowest limit; and this examination cannot fail to
throw much light on the exact distribution of the energy imparted to a
dynamo machine and the laws by which this distribution is governed.
But would this examination ever have taken place--would the costly
experiments which render it feasible ever have been performed--if the
dynamo machine was still under the undisputed control of pure science,
and had not become subject to the sway of the capitalist and the
engineer?

Of course the electric telegraph affords an earlier and perhaps as good
an illustration of the same fact. The discovery that electricity would
pass along a wire and actuate a needle at the other end was at first a
purely scientific one; and it was only gradually that its importance,
from an industrial point of view, came to be recognized. Here again art
owes to pure science the creation of a complete and important branch of
engineering, whose works are spread like a net over the whole face
of the globe. On the other hand our knowledge of electricity, and
especially of the electrochemical processes which go on in the working
of batteries, has been enormously improved in consequence of the use of
such batteries for the purposes of telegraphy.

Let us turn to another example in a different branch of science.
Whichever of our modern discoveries we may consider to be the most
startling and important, there can I think be no doubt that the most
beautiful is that of the spectroscope. It has enabled us to do that
which but a few years before its introduction was taken for the very
type of the impossible, viz., to study the chemical composition of the
stars; and it is giving us clearer and clearer insight every day into
the condition of the great luminary which forms the center of our
system. Still, however beautiful and interesting such results may be,
it might well be thought that they could never have any practical
application, and that the spectroscope at least would remain an
instrument of science, but of science alone. This, however, is not the
case. Some thirty years since, Mr. Bessemer conceived the idea that
the injurious constituents of raw iron--such as silicon, sulphur,
etc.--might be got rid of by simple oxidation. The mass of crude metal
was heated to a very high temperature; atmospheric air was forced
through it at a considerable pressure; and the oxygen uniting with these
metalloids carried them off in the form of acid gases. The very act
of union generated a vast quantity of heat, which itself assisted the
continuance of the process; and the gas therefore passed off in a highly
luminous condition. But the important point was to know where to
stop; to seize the exact moment when all or practically all hurtful
ingredients had been removed, and before the oxygen had turned from them
to attack the iron itself. How was this point to be ascertained? It was
soon suggested that each of these gases in its incandescent state would
show its own peculiar spectrum; and that if the flame rushing out of the
throat of the converter were viewed through a spectroscope, the moment
when any substance such as sulphur, had disappeared would be known
by the disappearance of the corresponding lines in the spectrum. The
anticipation, it is needless to say, was verified, and the spectroscope,
though now superseded, had for a time its place among the regular
appliances necessary for the carrying on of the Bessemer process.

This process itself, with all the momentous consequences, mechanical,
commercial, and economical, which it has entailed, might be brought
forward as a witness on our side; for it was almost completely worked
out in the laboratory before being submitted to actual practice. In this
respect it stands in marked contrast to the earlier processes for the
making of iron and steel, which were developed, it is difficult to say
how, in the forge or furnace itself, and amid the smoke and din of
practical work. At the same time the experiments of Bessemer were
for the most part carried out with a distinct eye to their future
application in practice, and their value for our present purpose is
therefore not so great. The same we believe may be said with regard
to the great rival of the Bessemer converter, viz., the Siemens open
hearth; although this forms in itself a beautiful application of the
scientific doctrine that steel stands midway, as regards proportion of
carbon, between wrought iron and pig iron, and ought therefore to be
obtainable by a judicious mixture of the two. The basic process is
the latest development, in this direction, of science as applied to
metallurgy. Here, by simply giving a different chemical constitution
to the clay lining of the converter, it is found possible to eliminate
phosphorus--an element which has successfully withstood the attack of
the Bessemer system. Now, to quote the words of a German eulogizer of
the new method, phosphorus has been turned from an enemy into a friend;
and the richer a given ore is in that substance, the more readily and
cheaply does it seem likely to be converted into steel.

These latter examples have been taken from the art of metallurgy; and it
may of course be said that, considering the intimate relations between
that art and the science of chemistry, there can be no wonder if the
former is largely dependent for its progress on the latter. I will
therefore turn to what may appear the most concrete, practical, and
unscientific of all arts--that, namely, of the mechanical engineer; and
we shall find that even here examples will not fail us of the boons
which pure science has conferred upon the art of construction, nor even
perhaps of the reciprocal advantages which she has derived from the
connection.

The address of Mr. Westmacott, from which I have already taken my text,
supplies in itself more than one instance of the kind we seek--instances
emphasized by papers read at the meeting where the address was spoken.
Let us take, first, the manufacture of sugar from beetroot. This
manufacture was forced into prominence in the early years of this
century, when the Continental blockade maintained by England against
Napoleon prevented all importation of sugar from America; and it has now
attained very large dimensions, as all frequenters of the Continent must
be aware. The process, as exhaustively described by a Belgian engineer,
M. Melin, offers several instances of the application of chemical and
physical science to practical purposes. Thus, the first operation in
making sugar from beetroot is to separate the juice from the flesh, the
former being as much as 95 per cent. of the whole weight. Formerly this
was accomplished by rasping the roots into a pulp, and then pressing the
pulp in powerful hydraulic presses; in other words, by purely mechanical
means. This process is now to a large extent superseded by what is
called the diffusion process, depending on the well known physical
phenomena of _endosmosis_ and _exosmosis_. The beetroot is cut up into
small slices called "cossettes," and these are placed in vessels filled
with water. The result is that a current of endosmosis takes place from
the water toward the juice in the cells, and a current of exosmosis
from the juice toward the water. These currents go on cell by cell, and
continue until a state of equilibrium is attained. The richer the water
and the poorer the juice, the sooner does this equilibrium take place.
Consequently the vessels are arranged in a series, forming what is
called a diffusion battery; the pure water is admitted to the first
vessel, in which the slices have already been nearly exhausted, and
subtracts from them what juice there is left. It then passes as a thin
juice to the next vessel, in which the slices are richer, and the
process begins again. In the last vessel the water which has already
done its work in all the previous vessels comes into contact with fresh
slices, and begins the operation upon them. The same process has been
applied at the other end of the manufacture of sugar. After the juice
has been purified and all the crystallizable sugar has been separated
from it by boiling, there is left a mass of molasses, containing so much
of the salts of potassium and sodium that no further crystallization of
the yet remaining sugar is possible. The object of the process called
osmosis is to carry off these salts. The apparatus used, or osmogene,
consists of a series of trays filled alternately with molasses and
water, the bottoms being formed of parchment paper. A current passes
through this paper in each direction, part of the water entering the
molasses, and part of the salts, together with a certain quantity of
sugar, entering the water. The result, of thus freeing the molasses
from the salts is that a large part of the remaining sugar can now be
extracted by crystallization.

Another instance in point comes from a paper dealing with the question
of the construction of long tunnels. In England this has been chiefly
discussed of late in connection with the Channel Tunnel, where, however,
the conditions are comparatively simple. It is of still greater
importance abroad. Two tunnels have already been pierced through the
Alps; a third is nearly completed; and a fourth, the Simplon Tunnel,
which will be the longest of any, is at this moment the subject of
a most active study on the part of French engineers. In America,
especially in connection with the deep mines of the Western States,
the problem is also of the highest importance. But the driving of such
tunnels would be financially if not physically impossible, but for
the resources which science has placed in our hands, first, by the
preparation of new explosives, and, secondly, by methods of dealing with
the very high temperatures which have to be encountered. As regards the
first, the history of explosives is scarcely anything else than a record
of the application of chemical principles to practical purposes--a
record which in great part has yet to be written, and on which we cannot
here dwell. It is certain, however, that but for the invention of
nitroglycerine, a purely chemical compound, and its development in
various forms, more or less safe and convenient, these long tunnels
would never have been constructed. As regards the second point, the
question of temperature is really the most formidable with which the
tunnel engineer has to contend. In the St. Gothard Tunnel, just before
the meeting of the two headings in February, 1880, the temperature
rose as high as 93° Fahr. This, combined with the foulness of the air,
produced an immense diminution in the work done per person and per horse
employed, while several men were actually killed by the dynamite gases,
and others suffered from a disease which was traced to a hitherto
unknown species of internal worm. If the Simplon Tunnel should be
constructed, yet higher temperatures may probably have to be dealt with.
Although science can hardly be said to have completely mastered these
difficulties, much has been done in that direction. A great deal of
mechanical work has of course to be carried on at the face or far end of
such a heading, and there are various means by which it might be done.
But by far the most satisfactory solution, in most cases at least, is
obtained by taking advantage of the properties of compressed air. Air
can be compressed at the end of the tunnel either by steam-engines,
or, still better, by turbines where water power is available. This
compressed air may easily be led in pipes to the face of the heading,
and used there to drive the small engines which work the rock-drilling
machines, etc. The efficiency of such machines is doubtless low, chiefly
owing to the physical fact that the air is heated by compression, and
that much of this heat is lost while it traverses the long line of pipes
leading to the scene of action. But here we have a great advantage from
the point of view of ventilation; for as the air gained heat while being
compressed, so it loses heat while expanding; and the result is that a
current of cold and fresh air is continually issuing from the
machines at the face of the heading, just where it is most wanted. In
consequence, in the St. Gothard, as just alluded to, the hottest parts
were always some little distance behind the face of the heading.
Although in this case as much as 120,000 cubic meters of air (taken
at atmospheric pressure) were daily poured into the heading, yet the
ventilation was very insufficient. Moreover, the high pressure which is
used for working the machines is not the best adapted for ventilation;
and in the Arlberg tunnel separate ventilating pipes are employed,
containing air compressed to about one atmosphere, which is delivered
in much larger quantities although not at so low a temperature.
In connection with this question of ventilation a long series of
observations have been taken at the St. Gothard, both during and since
the construction; these have revealed the important physical fact
(itself of high practical importance) that the barometer never stands at
the same level on the two sides of a great mountain chain; and so have
made valuable contributions to the science of meteorology.

Another most important use of the same scientific fact, namely, the
properties of compressed air, is found in the sinking of foundations
below water. When the piers of a bridge, or other structure, had to be
placed in a deep stream, the old method was to drive a double row of
piles round the place and fill them in with clay, forming what is
called a cofferdam. The water was pumped out from the interior, and the
foundation laid in the open. This is always a very expensive process,
and in rapid streams is scarcely practicable. In recent times large
bottomless cases, called caissons, have been used, with tubes attached
to the roof, by which air can be forced into or out of the interior.
These caissons are brought to the site of the proposed pier, and are
there sunk. Where the bottom is loose sandy earth, the vacuum process,
as it is termed, is often employed; that is, the air is pumped out from
the interior, and the superincumbent pressure then causes the caisson
to sink and the earth to rise within it. But it is more usual to employ
what is called the plenum process, in which air under high pressure
is pumped into the caisson and expels the water, as in a diving bell.
Workmen then descend, entering through an air lock, and excavate the
ground at the bottom of the caisson, which sinks gradually as the
excavation continues. Under this system a length of some two miles of
quay wall is being constructed at Antwerp, far out in the channel of the
river Scheldt. Here the caissons are laid end to end with each other,
along the whole curve of the wall, and the masonry is built on the top
of them within a floating cofferdam of very ingenious construction.

There are few mechanical principles more widely known than that of
so-called centrifugal force; an action which, though still a puzzle
to students, has long been thoroughly understood. It is, however,
comparatively recently that it has been applied in practice. One of the
earliest examples was perhaps the ordinary governor, due to the genius
of Watt. Every boy knows that if he takes a weight hanging from a string
and twirls it round, the weight will rise higher and revolve in a larger
circle as he increases the speed. Watt saw that if he attached such an
apparatus to his steam engine, the balls or weights would tend to rise
higher whenever the engine begun to run faster, that this action might
be made partly to draw over the valve which admitted the steam, and that
in this way the supply of steam would be lessened, and the speed would
fall. Few ideas in science have received so wide and so successful an
application as this. But of late years another property of centrifugal
force has been brought into play. The effect of this so-called force is
that any body revolving in a circle has a continual tendency to fly off
at a tangent; the amount of this tendency depending jointly on the mass
of the body and on the velocity of the rotation. It is the former of
these conditions which is now taken advantage of. For if we have a
number of particles all revolving with the same velocity, but of
different specific gravities, and if we allow them to follow their
tendency of moving off at a tangent, it is evident that the heaviest
particles, having the greatest mass, will move with the greatest energy.
The result is that, if we take a mass of such particles and confine them
within a circular casing, we shall find that, having rotated this casing
with a high velocity and for a sufficient time, the heaviest particles
will have settled at the outside and the lightest at the inside, while
between the two there will be a gradation from the one to the other.
Here, then, we have the means of separating two substances, solid
or liquid, which are intimately mixed up together, but which are of
different specific gravities. This physical principle has been taken
advantage of in a somewhat homely but very important process, viz., the
separation of cream from milk. In this arrangement the milk is charged
into a vessel something of the shape and size of a Gloucester cheese,
which stands on a vertical spindle and is made to rotate with a velocity
as high as 7,000 revolutions per minute. At this enormous speed the
milk, which is the heavier, flies to the outside, while the cream
remains behind and stands up as a thin layer on the inside of the
rotating cylinder of fluid. So completely does this immense speed
produce in the liquid the characteristics of a solid, that if the
rotating shell of cream be touched by a knife it emits a harsh, grating
sound, and gives the sensation experienced in attempting to cut a stone.
The separation is almost immediately complete, but the difficult point
was to draw off the two liquids separately and continuously without
stopping the machine. This has been simply accomplished by taking
advantage of another principle of hydromechanics. A small pipe opening
just inside the shell of the cylinder is brought back to near the
center, where it rises through a sort of neck and opens into an exterior
casing. The pressure due to the velocity causes the skim milk to rise in
this pipe and flow continuously out at the inner end. The cream is at
the same time drawn off by a similar orifice made in the same neck and
leading into a different chamber.

Centrifugal action is not the only way in which particles of different
specific gravity can he separated from each other by motion only. If
a rapid "jigging" or up-and-down motion be given to a mixture of such
particles, the tendency of the lighter to fly further under the action
of the impulse causes them gradually to rise to the upper surface; this
surface being free in the present case, and the result being therefore
the reverse of what happens in the rotating chamber. If such a mixture
be examined after this up-and down motion has gone on for a considerable
period, it will be found that the particles are arranged pretty
accurately in layers, the lightest being at the top and the heaviest
at the bottom. This principle has long been taken advantage of in such
cases as the separation of lead ores from the matrix in which they are
embedded. The rock in these cases is crushed into small fragments, and
placed on a frame having a rapid up-and-down-motion, when the heavy lead
ore gradually collects at the bottom and the lighter stone on the top.
To separate the two the machine must be stopped and cleared by hand. In
the case of coal-washing, where the object is to separate fine coal from
the particles of stone mixed with it, this process would be very costly,
and indeed impossible, because a current of water is sweeping through
the whole mass. In the case of the Coppee coal-washer, the desired
end is achieved in a different and very simple manner. The well known
mineral felspar has a specific gravity intermediate between that of the
coal and the shale, or stone, with which it is found intermixed. If,
then, a quantity of felspar in small fragments is thrown into the
mixture, and the whole then submitted to the jigging process, the result
will be that the stone will collect on the top, and the coal at the
bottom, with a layer of felspar separating the two. A current of water
sweeps through the whole, and is drawn off partly at the top, carrying
with it the stone, and partly at the bottom, carrying with it the fine
coal.

The above are instances where science has come to the aid of
engineering. Here is one in which the obligation is reversed. The rapid
stopping of railroad trains, when necessary, by means of brakes, is a
problem which has long occupied the attention of many engineers; and the
mechanical solutions offered have been correspondingly numerous. Some
of these depend on the action of steam, some of a vacuum, some of
compressed air, some of pressure-water; others again ingeniously utilize
the momentum of the wheels themselves. But for a long time no effort
was made by any of these inventors thoroughly to master the theoretical
conditions of the problem before them. At last, one of the most
ingenious and successful among them, Mr. George Westinghouse, resolved
to make experiments on the subject, and was fortunate enough to
associate with himself Capt. Douglas Galton. Their experiments, carried
on with rare energy and perseverance, and at great expense, not only
brought into the clearest light the physical conditions of the question
(conditions which were shown to be in strict accordance with theory),
but also disclosed the interesting scientific fact that the friction
between solid bodies at high velocities is not constant, as the
experiments of Morin had been supposed to imply, but diminishes rapidly
as the speed increases--a fact which other observations serve to
confirm.

The old scientific principle known as the hydrostatic paradox, according
to which a pressure applied at any point of an inclosed mass of liquid
is transmitted unaltered to every other point, has been singularly
fruitful in practical applications. Mr. Bramah was perhaps the first
to recognize its value and importance. He applied it to the well known
Bramah press, and in various other directions, some of which were less
successful. One of these was a hydraulic lift, which Mr. Bramah proposed
to construct by means of several cylinders sliding within each other
after the manner of the tubes of a telescope. His specification of
this invention sufficiently expresses his opinion of its value, for it
concludes as follows: "This patent does not only differ in its nature
and in its boundless extent of claims to novelty, but also in its claims
to merit and superior utility compared with any other patent ever
brought before or sanctioned by the legislative authority of any
nation." The telescope lift has not come into practical use; but lifts
worked on the hydraulic principle are becoming more and more common
every day. The same principle has been applied by the genius of Sir
William Armstrong and others to the working of cranes and other machines
for the lifting of weights, etc.; and under the form of the accumulator,
with its distributing pipes and hydraulic engines, it provides a store
of power always ready for application at any required point in a large
system, yet costing practically nothing when not actually at work. This
system of high pressure mains worked from a central accumulator has
been for some years in existence at Hull, as a means of supplying power
commercially for all the purposes needed in a large town, and it is
at this moment being carried out on a wider scale in the East End of
London.

Taking advantage of this system, and combining with it another
scientific principle of wide applicability, Mr. J.H. Greathead has
brought out an instrument called the "injector hydrant," which seems
likely to play an important part in the extinguishing of fires. This
second principle is that of the lateral induction of fluids, and may be
thus expressed in the words of the late William Froude: "Any surface
which in passing through a fluid experiences resistance must in so doing
impress on the particles which resist it a force in the line of motion
equal to the resistance." If then these particles are themselves part
of a fluid, it will result that they will follow the direction of the
moving fluid and be partly carried along with it. As applied in the
injector hydrant, a small quantity of water derived from the high
pressure mains is made to pass from one pipe into another, coming in
contact at the same time with a reservoir of water at ordinary pressure.
The result is that the water from the reservoir is drawn into the second
pipe through a trumpet-shaped nozzle, and may be made to issue as
a stream to a considerable height. Thus the small quantity of
pressure-water, which, if used by itself, would perhaps rise to a height
of 500 feet, is made to carry with it a much larger quantity to a much
smaller height, say that of an ordinary house.

The above are only a few of the many instances which might be given to
prove the general truth of the fact with which we started, namely, the
close and reciprocal connection between physical science and mechanical
engineering, taking both in their widest sense. It may possibly be worth
while to return again to the subject, as other illustrations arise.
Two such have appeared even at the moment of writing, and though their
practical success is not yet assured, it may be worth while to cite
them. The first is an application of the old principle of the siphon to
the purifying of sewage. Into a tank containing the sewage dips a siphon
pipe some thirty feet high, of which the shorter leg is many times
larger than the longer. When this is started, the water rises slowly and
steadily in the shorter column, and before it reaches the top has left
behind it all or almost all of the solid particles which it previously
held in suspension. These fall slowly back through the column and
collect at the bottom of the tank, to be cleared out when needful. The
effluent water is not of course chemically pure, but sufficiently so
to be turned into any ordinary stream. The second invention rests on
a curious fact in chemistry, namely, that caustic soda or potash will
absorb steam, forming a compound which has a much higher temperature
than the steam absorbed. If, therefore, exhaust-steam be discharged
into the bottom of a vessel containing caustic alkali, not only will it
become condensed, but this condensation will raise the temperature of
the mass so high that it may be employed in the generation of fresh
steam. It is needless to observe how important will be the bearing of
this invention upon the working of steam engines for many purposes,
if only it can be established as a practical success. And if it is so
established there can be no doubt that the experience thus acquired will
reveal new and valuable facts with regard to the conditions of chemical
combination and absorption, in the elements thus brought together.

WALTER R. BROWNE.

       *       *       *       *       *




HYDRAULIC PLATE PRESS.


One of the most remarkable and interesting mechanical arrangements at
the Imperial Navy Yard at Kiel, Germany, is the iron clad plate bending
machine, by means of which the heavy iron clad plates are bent for the
use of arming iron clad vessels.

Through the mechanism of this remarkable machine it is possible to bend
the strongest and heaviest iron clad plates--in cold condition--so that
they can be fitted close on to the ship's hull, as it was done with the
man-of-war ships Saxonia, Bavaria, Wurtemberg, and Baden, each of which
having an iron strength of about 250 meters.

[Illustration: IMPROVED HYDRAULIC PLATE PRESS.]

One may make himself a proximate idea of the enormous power of pressure
of such a machine, if he can imagine what a strength is needed to bend
an iron plate of 250 meters thickness, in cold condition; being also 1.5
meters in width, and 5.00 meters in length, and weighing about 14,555
kilogrammes, or 14,555 tons.

The bending of the plates is done as follows: As it is shown in the
illustration, connected herewith, there are standing, well secured into
the foundation, four perpendicular pillars, made of heavy iron, all
of which are holding a heavy iron block, which by means of female nut
screws is lifted and lowered in a perpendicular direction. Beneath the
iron block, between the pillars, is lying a large hollow cylinder in
which the press piston moves up and down in a perpendicular direction.
These movements are caused by a small machine, or, better, press
pump--not noticeable in the illustration--which presses water from
a reservoir through a narrow pipe into the large hollow cylinder,
preventing at the same time the escape or return of the water so forced
in. The hollow cylinder up to the press piston is now filled with water,
so remains no other way for the piston as to move on to the top. The
iron clad plate ready to undergo the bending process is lying between
press piston and iron block; under the latter preparations are already
made for the purpose of giving the iron clad plate such a form as it
will receive through the bending process. After this the press piston
will, with the greatest force, steadily but slowly move upward, until
the iron clad plate has received its intended bending.

Lately the hydraulic presses are often used as winding machines, that
is, they are used as an arrangement to lift heavy loads up on elevated
points.

The essential contrivance of a hydraulic press is as follows:

One thinks of a powerful piston, which, through, human, steam, or water
power, is set in a moving up-and-down motion. Through the ascent of the
piston, is by means of a drawing pipe, ending into a sieve, the water
absorbed out of a reservoir, and by the lowering of the piston water is
driven out of a cylinder by means of a narrow pipe (communication pipe)
into a second cylinder, which raises a larger piston, the so-called
press piston. (See illustration.)

One on top opening drawing valve, on the top end of the drawing pipe
prevents the return of the water by the going down of the piston; and a
barring valve, which is lifted by the lowering of the piston, obstructs
the return of the water by the ascent of the piston, while the drawing
valve is lifted by means of water absorbed by the small drawing
pipe.--_Illustrirte Zeitung_.

       *       *       *       *       *




FAST PRINTING PRESS FOR ENGRAVINGS.


_Uber Land und Meer_, which is one of the finest illustrated newspapers
published in Germany, gives the following: We recently gave our readers
an insight into the establishment of _Uber Land und Meer_, and to-day we
show them the machine which each week starts our paper on its journey
around the world--a machine which embodies the latest and greatest
progress in the art of printing. The following illustration represents
one of the three fast presses which the house of Hallberger employs in
the printing of its illustrated journals.

With the invention of the cylinder press by Frederick König was verified
the saying that the art of printing had lent wings to words. Everywhere
the primitive hand-press had to make way for the steam printing machine;
but even this machine, since its advent in London in 1810, has itself
undergone so many changes that little else remains of König's invention
than the principle of the cylinder. The demands of recent times for
still more rapid machines have resulted in the production of presses
printing from a continuous roll or "web" of paper, from cylinders
revolving in one given direction. The first of this class of presses
(the "Bullock" press) was built in America. Then England followed,
and there the first newspaper to make use of one was the _Times_. The
Augsburg Machine Works were the first to supply Germany with them, and
it was this establishment which first undertook to apply the principle
of the web perfecting press (first intended for newspaper work only,
where speed rather than fine work is the object sought) to book
printing, in which far greater accuracy and excellence is required, and
the result has been the construction of a rotary press for the highest
grade of illustrated periodical publications, which meets all the
requirements with the most complete success.

[Illustration: IMPROVED FAST PRINTING PRESS FOR ENGRAVERS]

The building of rotary presses for printing illustrated papers was
attempted as early as 1874 or 1875 in London, by the _Times_, but
apparently without success, as no public mention has ever been made of
any favorable result. The proprietor of the _London Illustrated News_
obtained better results. In 1877 an illustrated penny paper, an
outgrowth of his great journal, was printed upon a rotary press which
was, according to his statement, constructed by a machinist named
Middleton. The first one, however, did not at all meet the higher
demands of illustrated periodical printing, and, while another machine
constructed on the same principle was shown in the Paris Exposition of
1878, its work was neither in quality nor quantity adequate to the needs
of a largely circulated illustrated paper. A second machine, also on
exhibition at the same time, designed and built by the celebrated French
machinist, P. Alauzet, could not be said to have attained the object.
Its construction was undertaken long after the opening of the
Exposition, and too late to solve the weighty question. But the
half-successful attempt gave promise that the time was at hand when a
press could be built which could print our illustrated periodicals more
rapidly, and a conference with the proprietors of the Augsburg Machine
Works resulted in the production by them of the three presses from which
_Uber Land und Meer_ and _Die Illustrirte Welt_ are to-day issued. As
a whole and in detail, as well as in its productions, the press is the
marvel of mechanic and layman.

As seen in the illustration, the web of paper leaves the roll at its
right, rising to a point at the top where it passes between two hollow
cylinders covered with felt and filled with steam, which serve to dampen
the paper as may be necessary, the small hand-wheel seen above these
cylinders regulating the supply of steam. After leaving these cylinders
the paper descends sloping toward the right, and passes through two
highly polished cylinders for the purpose of recalendering. After this
it passes under the lowest of the three large cylinders of the press,
winds itself in the shape of an S toward the outside and over the middle
cylinder, and leaves the press in an almost horizontal line, after
having been printed on both sides, and is then cut into sheets. The
printing is done while the paper is passing around the two white
cylinders. The cylinder carrying the first form is placed inside and
toward the center of the press, only a part of its cog-wheel and its
journal being shown in the engraving. The second form is placed upon the
uppermost cylinder, and is the outside or cut form. Each one of the form
cylinders requires a separate inking apparatus. That of the upper one is
placed to the right at the top, and the bottom one is also at the right,
but inside. Each one has a fountain the whole breadth of the press,
in which the ink is kept, and connected with which, by appropriate
mechanism, is a system of rollers for the thorough distribution of the
ink and depositing it upon the forms.

The rapidity with which the impressions follow each other does not allow
any time for the printing on the first side to dry, and as a consequence
the freshly printed sheet coming in contact with the "packing" of the
second cylinder would so soil it as to render clean printing absolutely
impossible. To avoid this, a second roll of paper is introduced into the
machine, and is drawn around the middle cylinder beneath the paper which
has already been printed upon one side, and receives upon its surface
all "offset," thus protecting and keeping perfectly clean both the
printed paper and the impression cylinder. This "offset" web, as it
leaves the press, is wound upon a second roller, which when full is
exchanged for the new empty roller--a very simple operation.

The machines print from 3,500 to 4,000 sheets per hour _upon both
sides_, a rate of production from twenty-eight to thirty-two times as
great as was possible upon the old-fashioned hand-press, which was
capable of printing not more than 250 copies upon _one side_ in the same
time.

The device above described for preventing "offset" is, we believe, the
invention of Mr. H.J. Hewitt, a well known New York printer, 27 Rose
Street.

       *       *       *       *       *




FRENCH CANNON.


Five new cannons, the largest yet manufactured in France, have been
successfully cast in the foundry of Ruelle near Angouleme. They are made
of steel, and are breech loading. The weight of each is 97 tons, without
the carriage. The projectile weighs 1,716 pounds, and the charge or
powder is 616 pounds. To remove them a special wagon with sixteen wheels
has had to be constructed, and the bridges upon the road from Ruelle to
Angouleme not being solid enough to bear the weight of so heavy a
load, a special roadway will be constructed for the transport of these
weapons, which are destined for coast defences and ironclads.

       *       *       *       *       *




WOODLANDS, STOKE POGIS, BUCKS.


The illustration represents a house recently reconstructed. The
dining-room wing was alone left in the demolition of the old premises,
and this part has been decorated with tile facings, and otherwise
altered to be in accordance with the new portion. The house is
pleasantly situated about a mile from Stoke Church of historic fame,
in about 15 acres of garden, shrubbery, and meadow land. The hall and
staircase have been treated in wainscot oak, and the whole of the work
has been satisfactorily carried out by Mr. G. Almond, builder, of
Burnham, under the superintendence of Messrs. Thurlow & Cross,
architects.--_The Architect_.

[Illustration: WOODLANDS, STOKE POGES, BUCKS]

       *       *       *       *       *




CHINA GRASS.


The following article appeared in a recent number of the _London Times_:

The subject of the cultivation and commercial utilization of the China
grass plant, or rhea, has for many years occupied attention, the
question being one of national importance, particularly as affecting
India. Rhea which is also known under the name of ramie, is a textile
plant which was indigenous to China and India. It is perennial, easy of
cultivation, and produces a remarkably strong fiber. The problem of its
cultivation has long being solved, for within certain limits rhea can
be grown in any climate. India and the British colonies offer unusual
facilities, and present vast and appropriate fields for that enterprise,
while it can be, and is, grown in most European countries. All this has
long been demonstrated; not so, however, the commercial utilization of
the fiber, which up to the present time would appear to be a problem
only partially solved, although many earnest workers have been engaged
in the attempted solution.

There have been difficulties in the way of decorticating the stems of
this plant, and the Indian Government, in 1869, offered a reward of
£5,000 for the best machine for separating the fiber from the stems and
bark of rhea in its green or freshly cut state. The Indian Government
was led to this step by the strong conviction, based upon ample
evidence, that the only obstacle to the development of an extensive
trade in this product was the want of suitable means for decorticating
the plant. This was the third time within the present century that rhea
had become the subject of official action on the part of the Government,
the first effort for utilizing the plant dating from 1803, when Dr.
Roxburg started the question, and the second from 1840, when attention
was again directed to it by Colonel Jenkins.

The offer of £5,000, in 1869, led to only one machine being submitted
for trial, although several competitors had entered their names. This
machine was that of Mr. Greig, of Edinburgh, but after careful trial
by General (then Lieutenant Colonel) Hyde it was found that it did not
fulfill the conditions laid down by the Government, and therefore the
full prize of £5,000 was not awarded. In consideration, however, of the
inventor having made a _bona fide_ and meritorious attempt to solve
the question, he was awarded a donation of £1,500. Other unsuccessful
attempts were subsequently made, and eventually the offer of £5,000 was
withdrawn by the Government.

But although the prize was withdrawn, invention did not cease, and the
Government, in 1881, reoffered the prize of £5,500. Another competition
took place, at which several machines were tried, but the trials, as
before, proved barren of any practical results, and up to the present
time no machine has been found capable of dealing successfully with this
plant in the green state. The question of the preparation of the fiber,
however, continued to be pursued in many directions. Nor is this to be
wondered at when it is remembered that the strength of some rhea fiber
from Assam experimented with in 1852 by Dr. Forbes Royle, as compared
with St. Petersburg hemp, was in the ratio of 280 to 160, while the wild
rhea from Assam was as high as 343. But, above and beyond this, rhea has
the widest range of possible applications of any fiber, as shown by an
exhaustive report on the preparation and use of rhea fiber by Dr. Forbes
Watson, published in 1875, at which date Dr. Watson was the reporter on
the products of India to the Secretary of State, at the India Office.
Last year, however, witnessed the solution of the question of
decortication in the green state in a satisfactory manner by M.A.
Favier's process, as reported by us at the time.

This process consists in subjecting the plant to the action of steam for
a period varying from 10 to 25 minutes, according to the length of time
the plant had been cut. After steaming, the fiber and its adjuncts
were easily stripped from the wood. The importance and value of this
invention will be realized, when it is remembered that the plant is
cultivated at long distances from the localities where the fiber
is prepared for the market. The consequence is, that for every
hundredweight of fiber about a ton of woody material has to be
transported. Nor is this the only evil, for the gummy matter in which
the fiber is embedded becomes dried up during transport, and the
separation of the fiber is thus rendered difficult, and even impossible,
inasmuch as some of the fiber is left adhering to the wood.

M. Favier's process greatly simplifies the commercial production of the
fiber up to a certain point, for, at a very small cost, it gives the
manufacturer the whole of the fiber in the plant treated. But it still
stops short of what is required, in that it delivers the fiber in
ribbons, with its cementitious matter and outer skin attached. To remove
this, various methods have been tried, but, as far as we are aware,
without general success--that is to say, the fiber cannot always
be obtained of such a uniformly good quality as to constitute a
commercially reliable article. Such was the position of the question
when, about a year ago, the whole case was submitted to the
distinguished French chemist, Professor Fremy, member of the Institute
of France, who is well-known for his researches into the nature of
fibrous plants, and the question of their preparation for the market.
Professor Fremy thoroughly investigated the matter from a chemical point
of view, and at length brought it to a successful and, apparently, a
practical issue.

One great bar to previous success would appear to have been the absence
of exact knowledge as to the nature of the constituents of that portion
of the plant which contains the fiber, or, in other words, the casing or
bark surrounding the woody stem of the rhea. As determined by Professor
Fremy, this consists of the cutose, or outer skin, within which is the
vasculose containing the fiber and other conjoined matter, known as
cellulose, between which and the woody stem is the pectose, or gum,
which causes the skin or bark, as a whole, fiber included, to adhere to
the wood. The Professor, therefore, proceeded to carefully investigate
the nature of these various substances, and in the result he found
that the vasculose and pectose were soluble in an alkali under certain
conditions, and that the cellulose was insoluble. He therefore dissolves
out the cutose, vasculose, and pectose by a very simple process,
obtaining the fiber clean, and free from all extraneous adherent matter,
ready for the spinner.

In order, however, to insure as a result a perfectly uniform and
marketable article, the Professor uses various chemicals at the several
stages of the process. These, however, are not administered haphazard,
or by rule of thumb, as has been the case in some processes bearing in
the same direction, and which have consequently failed, in the sense
that they have not yet taken their places as commercial successes. The
Professor, therefore, carefully examines the article which he has to
treat, and, according to its nature and the character of its components,
he determines the proportions of the various chemicals which he
introduces at the several stages. All chance of failure thus appears to
be eliminated, and the production of a fiber of uniform and reliable
quality removed from the region of doubt into that of certainty. The two
processes of M. Favier and M. Fremy have, therefore, been combined, and
machinery has been put up in France on a scale sufficiently large
to fairly approximate to practical working, and to demonstrate the
practicability of the combined inventions.

The experimental works are situated in the Route d'Orleans, Grand
Montrouge, just outside Paris, and a few days ago a series of
demonstrations were given there by Messrs. G.W.H. Brogden and Co., of
Gresham-house, London. The trials were carried out by M. Albert Alroy,
under the supervision of M. Urbain, who is Professor Fremy's chief
assistant and copatentee, and were attended by Dr. Forbes Watson, Mr.
M. Collyer, Mr. C.J. Taylor, late member of the General Assembly, New
Zealand, M. Barbe, M. Favier, Mr. G. Brogden, Mr. Caspar, and a number
of other gentlemen representing those interested in the question at
issue. The process, as carried out, consists in first treating the rhea
according to M. Favier's invention. The apparatus employed for this
purpose is very simple and inexpensive, consisting merely of a stout
deal trough or box, about 8 ft. long, 2 ft. wide, and 1 ft. 8 in. deep.
The box has a hinged lid and a false open bottom, under which steam is
admitted by a perforated pipe, there being an outlet for the condensed
water at one end of the box. Into this box the bundles of rhea were
placed, the lid closed, steam turned on, and in about twenty minutes it
was invariably found that the bark had been sufficiently softened to
allow of its being readily and rapidly stripped off by hand, together
with the whole of the fiber, in what may be called ribbons. Thus the
process of decortication is effectively accomplished in a few minutes,
instead of requiring, as it sometimes does in the retting process, days,
and even weeks, and being at the best attended with uncertainty as
to results, as is also the case when decortication is effected by
machinery.

Moreover, the retting process, which is simply steeping the cut plants
in water, is a delicate operation, requiring constant watching, to say
nothing of its serious inconvenience from a sanitary point of view, on
account of the pestilential emanations from the retteries. Decortication
by steam having been effected, the work of M. Favier ceases, and
the process is carried forward by M. Fremy. The ribbons having been
produced, the fiber in them has to be freed from the mucilaginous
secretions. To this end, after examination in the laboratory, they are
laid on metal trays, which are placed one above the other in a vertical
perforated metal cylinder. When charged, this cylinder is placed within
a strong iron cylinder, containing a known quantity of water, to which
an alkali is added in certain proportions. Within the cylinder is a
steam coil for heating the water, and, steam having been turned on, the
temperature is raised to a certain point, when the cylinder is closed
and made steam-tight. The process of boiling is continued under pressure
until the temperature--and consequently the steam pressure--within the
cylinder has attained a high degree.

On the completion of this part of the process, which occupies about
four hours, and upon which the success of the whole mainly depends,
the cementitious matter surrounding the fiber is found to have been
transformed into a substance easily dissolved. The fibrous mass is then
removed to a centrifugal machine, in which it is quickly deprived of its
surplus alkaline moisture, and it is then placed in a weak solution of
hydrochloric acid for a short time. It is then transferred to a bath
of pure cold water, in which it remains for about an hour, and it is
subsequently placed for a short time in a weak acid bath, after which it
is again washed in cold water, and dried for the market. Such are the
processes by which China grass may become a source of profit alike to
the cultivator and the spinner. A factory situate at Louviers has been
acquired, where there is machinery already erected for preparing the
fiber according to the processes we have described, at the rate of one
ton per day. There is also machinery for spinning the fiber into yarns.
These works were also visited by those gentlemen who were at the
experimental works at Montrouge, and who also visited the Government
laboratory in Paris, of which Professor Fremy is chief and M. Urbain
_sous-chef_, and where those gentlemen explained the details of their
process and made their visitors familiar with the progressive steps of
their investigations.

With regard to the rhea treated at Montrouge, we may observe that it was
grown at La Reolle, near Bordeaux. Some special experiments were also
carried out by Dr. Forbes Watson with some rhea grown by the Duke of
Wellington at Stratfield-saye, his Grace having taken an active interest
in the question for some years past. In all cases the rhea was used
green and comparatively freshly cut. One of the objects of Dr. Watson's
experiments was, by treating rhea cut at certain stages of growth,
to ascertain at which stage the plant yields the best fiber, and
consequently how many crops can be raised in the year with the best
advantage.

This question has often presented itself as one of the points to be
determined, and advantage has been taken of the present opportunity with
a view to the solution of the question. Mr. C.J. Taylor also took with
him a sample of New Zealand flax, which was successfully treated by
the process. On the whole, the conclusion is that the results of
the combined processes, so far as they have gone, are eminently
satisfactory, and justify the expectation that a large enterprise in the
cultivation and utilization of China grass is on the eve of being opened
up, not only in India and our colonies, but possibly also much nearer
home.

       *       *       *       *       *




APPARATUS FOR HEATING BY GAS.


This new heating apparatus consists of a cast iron box, E, provided with
an inclined cover, F, into which are fixed 100 copper tubes that are
arranged in several lines, and form a semi-cylindrical heating surface.
The box, E, is divided into two compartments (Fig. 5), so that the air
and gas may enter simultaneously either one or both of the compartments,
according to the quantity of heat it is desired to have. Regulation is
effected by means of the keys, G and G', which open the gas conduits
of the solid and movable disk, H, which serves as a regulator for
distributing air through the two compartments. This disk revolves by
hand and may be closed or opened by means of a screw to which it is
fixed.

Beneath the tubes that serve to burn the mixture of air and gas, there
is placed a metallic gauze, I, the object of which is to prevent the
flames from entering the fire place box. These tubes traverse a sheet
iron piece, J, which forms the surface of the fire place, and are
covered with a layer of asbestos filaments that serve to increase the
calorific power of the apparatus.

[Illustration: GOMEZ'S APPARATUS FOR HEATING BY GAS.

FIG. 1.--Front View. Scale of 0.25 to 1. FIG. 2.--Section through AB.
FIG.3.--Plan View. FIG. 4.--Section through CD. FIG. 5.--Transverse
Section through the Fireplace. Scale of 0.50 to 1.]

The cast iron box, E, is inclosed within a base of refractory clay, L,
which is surmounted by a reflector, M, of the same material, that is
designed to concentrate the heat and increase its radiation. This
reflector terminates above in a dome, in whose center is placed a
refractory clay box. This latter, which is round, is provided in the
center with a cylinder that is closed above. The box contains a large
number of apertures, which give passage to the products of combustion
carried along by the hot air. The carbonic acid which such products
contain is absorbed by a layer of quick-lime that has previously been
introduced into the box, N.

This heating apparatus, which is inclosed within a cast iron casing
similar to that of an ordinary gas stove, is employed without a chimney,
thus permitting of its being placed against the wall or at any other
point whatever in the room to be heated.--_Annales Industrielles_.

       *       *       *       *       *




IMPROVED GAS BURNER FOR SINGEING MACHINES.


Since the introduction of the process of gas-singeing in finishing
textiles, many improvements have been made in the construction of the
machines for this purpose as well as in that of the burners, for the
object of the latter must be to effect the singeing not only evenly and
thoroughly, but at the same time with a complete combustion of the gas
and avoidance of sooty deposits upon the cloth. The latter object is
attained by what are called atmospheric or Bunsen burners, and in which
the coal gas before burning is mixed with the necessary amount of
atmospheric air. The arrangement under consideration, patented abroad,
has this object specially in view. The main gas pipe of the machine is
shown at A, being a copper pipe closed at one end and having a tap at
the other. On this pipe the vertical pipes, C, are screwed at stated
intervals, each being in its turn provided with a tap near its base. On
the top of each vertical table the burner, IJ, is placed, whose upper
end spreads in the shape of a fan, and allows the gas to escape through
a slit or a number of minute holes. Over the tube, C, a mantle, E, is
slipped, which contains two holes, HG, on opposite sides, and made
nearly at the height of the outlet of the gas. When the gas passes out
of this and upward into the burner, it induces a current of air up
through the holes, HG, and carries it along with it. By covering these
holes with a loose adjustable collar, the amount of admissible air can
be regulated so that the flame is perfectly non-luminous, and therefore
containing no free particles of carbon or soot. The distance of the
vertical tubes, C; and of the fan-shaped burners is calculated so that
the latter touch each other, and thus a continuous flame is formed,
which is found to be the most effective for singeing cloth. Should it be
deemed advisable to singe only part of the cloth, or a narrow piece,
the arrangement admits of the taps, D, being turned off as
desired.--_Textile Manufacturer_.

[Illustration]

       *       *       *       *       *




SILAS' CHRONOPHORE.


In many industries there are operations that have to be repeated
at regular intervals, and, for this reason, the construction of an
apparatus for giving a signal, not only at the hour fixed, but also at
equal intervals, is a matter of interest. The question of doing this has
been solved in a very elegant way by Mr. Silas in the invention of the
apparatus which we represent in Fig. 1. It consists of a clock whose
dial is provided with a series of small pins. The hands are insulated
from the case and communicate with one of the poles of a pile contained
in the box. The case is connected with the other pole. A small vibrating
bell is interposed in the circuit. If it be desired to obtain a signal
at a certain hour, the corresponding pin is inserted, and the hand
upon touching this closes the circuit, and the bell rings. The bell is
likewise inclosed within the box. There are two rows of pins--one of
them for hours, and the other for minutes. They are spaced according to
requirements. In the model exhibited by the house Breguet, at the Vienna
Exhibition, there were 24 pins for minutes and 12 for hours. Fig. 2
gives a section of the dial. It will be seen that the hands are provided
at the extremity with a small spring, r, which is itself provided with
a small platinum contact, p. The pins also carry a small platinum or
silver point, a. In front of the box there will be observed a small
commutator, M, (Fig. 1). The use of this is indicated in the diagram
(Fig. 3). It will be seen that, according as the plug, B, is introduced
into the aperture to the left or right, the bell. S, will operate as an
ordinary vibrator, or give but a single stroke.

[Illustration: FIG. 1.--SILAS' CHRONOPHORE.]

P is the pile; C is the dial; and A is the commutator.

It is evident that this apparatus will likewise be able to render
services in scientific researches and laboratory operations, by sparing
the operator the trouble of continually consulting his watch.--_La
Lumiere Electrique_.

[Illustration: FIG. 2.]

[Illustration: FIG. 3.]

       *       *       *       *       *

[THE GARDEN.]




THE ZELKOWAS.


Two of the three species which form the subject of this article are not
only highly ornamental, but also valuable timber trees. Until recently
they were considered to belong to the genus Planera, which, however,
consists of but a single New World species; now, they properly
constitute a distinct genus, viz., Zelkova, which differs materially
from the true Planer tree in the structure of the fruit, etc. Z.
crenata, from the Caucasus, and Z. acuminata, from Japan, are quick
growing, handsome trees, with smooth bark not unlike that of beech or
hornbeam; it is only when the trees are old that the bark is cast off in
rather large sized plates, as is the case with the planes. The habit of
both is somewhat peculiar; in Z. crenata especially there is a decided
tendency for all the main branches to be given off from one point;
these, too, do not spread, as for instance do those of the elm or beech,
but each forms an acute angle with the center of the tree. The trunks
are more columnar than those of almost all other hardy trees. Their
distinct and graceful habit renders them wonderfully well adapted for
planting for effect, either singly or in groups. The flowers, like those
of the elm, are produced before the leaves are developed; in color they
are greenish brown, and smell like those of the elder. It does not
appear that fruits have yet been ripened in England. All the Zelkowas
are easily propagated by layers or by grafting on the common elm.

[Illustration: YOUNG ZELKOWA TREE (21 FEET HIGH)]

_Zelkcova crenata_--The Caucasian Zelkowa is a native of the country
lying between the Black and the Caspian Sea between latitudes 35° and
47° of the north of Persia and Georgia. According to Loudon, it was
introduced to this country in 1760, and it appears to have been planted
both at Kew and Syon at about that date. A very full account of the
history, etc., of the Zelkowa, from which Loudon largely quotes, was
presented to the French Academy of Science by Michaux the younger, who
speaks highly of the value of the tree. In this he is fully corroborated
by Mirbel and Desfontaine, on whom devolved the duty of reporting on
this memoir. They say that it attains a size equal to that of the
largest trees of French forests, and recommend its being largely
planted. They particularly mention its suitability for roadside avenues,
and affirm that its leaves are never devoured by caterpillars, and that
the stems are not subject, to the canker which frequently ruins the elm.
The name Orme de Siberie, which is or was commonly applied to Zelkova
crenata in French books and gardens, is doubly wrong, for the tree is
neither an elm nor is it native of Siberia. In 1782 Michaux, the father
of the author of the paper above mentioned, undertook, under the
auspices, of a Monsieur (afterward Louis XVIII.), a journey into Persia,
in order to make botanical researches.

[Illustration: FOLIAGE OF A YOUNG ZELKOWA TREE, WITH FLOWERS AND FRUIT.]

"Having left Ispahan, in order to explore the province of Ghilan, he
found this tree in the forests which he traversed before arriving
at Recht, a town situated on the Caspian Sea. In this town he had
opportunities of remarking the use made of the wood, and of judging how
highly it was appreciated by the inhabitants." The first tree introduced
into Europe appears to have been planted by M. Lemonnier, Professor of
Botany in the Jardin des Plautes, etc., in his garden near Versailles.
This garden was destroyed in 1820, and the dimensions of the tree
when it was cut down were as follows: Height 70 feet, trunk 7 feet in
circumference at 5 feet from the ground. The bole of the trunk was 20
feet in length and of nearly uniform thickness; and the proportion of
heart-wood to sap-wood was about three quarters of its diameter. This
tree was about fifty years old, but was still in a growing state and in
vigorous health. The oldest tree existing in France at the time of the
publication of Loudon's great work, was one in the Jardin des Plantes,
which in 1831 was about 60 feet high. It was planted in 1786 (when a
sucker of four years old), about the same time as the limes which form
the grand avenue called the Allee de Buffon. "There is, however, a much
larger Zelkowa on an estate of M. le Comte de Dijon, an enthusiastic
planter of exotic trees, at Podenas, near Nerac, in the department of
the Lot et Garonne. This fine tree was planted in 1789, and on the 20th
of January, 1831. it measured nearly 80 feet high, and the trunk was
nearly 3 feet in diameter at 3 feet from the ground." A drawing of this
tree, made by the count in the autumn of that year, was lent to Loudon
by Michaux, and the engraving prepared from that sketch (on a scale of 1
inch to 12 feet) is herewith reproduced. At Kew the largest tree is one
near the herbarium (a larger one had to be cut down when the herbarium
was enlarged some years ago, and a section of the trunk is exhibited
in Museum No. 3). Its present dimensions are: height, 62 feet;
circumference of stem at 1 foot from the ground, 9 feet 8 inches; ditto
at ground level, 10 feet; Height of stem from ground to branches, 7
feet; diameter of head, 46 feet. The general habit of the tree is quite
that as represented in the engraving of the specimen at Podenas. The
measurements of the large tree at Syon House were, in 1834, according to
Loudon: Height, 54 feet; circumference of of stem, 6 feet 9 inches;
and diameter of head, 34 feet; the present dimensions, for which I am
indebted to Mr. Woodbridge, are: Height, 76 feet; girth of trunk at 2½
feet from ground, 10 feet; spread of branches, 36 feet.

[Illustration: FLOWERS AND FRUIT OF ZELKOVA CRENATA (_Planera
Richardi_).]

IDENTIFICATION.--Zelkova crenata, Spach in Ann. des Sc. nat. 2d ser. 15,
p. 358. D. C. Prodromus, xvii., 165 Rhamnus ulmoides, Güldenst. It.,
p. 313. R carpinifolius, Pall. Fl Rossica, 2 p. 24, tab. 10. Ulmus
polygama, L C. Richard in Mem. Acad. des Sciences de Paris, ann. 1781.
Planera Richardi, Michx. Fl. bor. Amer. 2, p. 248; C.A. Meyer, Enumer.
Causas. Casp., n. 354; Dunal in Bulletin Soc. cent d'Agricult. de
l'Herault. ann. 1841, 299, 303, et ann. 1843, 225, 236. Loudon, Arbor,
et Frut. Brit., vol. 3, p. 1409. Planera crenata, Desf. Cat. Hort. Paris
et hortul, fere omnium. Michaux fil. Mem. sur le Zelkowa, 1831. Planera
carpinifolia, Watson, Dend. Brit., t. 106. Koch Dendrologie, zweit
theil, sweit. Abtheil. p. 425.

[Illustration: ZELKOWA TREE AT PODENAS

Showing peculiar habit of branching. In old trees the effect is very
remarkable in winter as at Oxford, Versailles (_Petit Trianon_) and
Syon.]

_Var pendula_ (the weeping Zelkowa).--This is a form of which I do not
know the origin or history. It is simply a weeping variety of the common
Zelkowa. I first saw it in the Isleworth Nurseries of Messrs. C. Lee &
Son, and a specimen presented by them to Kew for the aboretum is now
growing freely. I suspect that the Zelkova crenata var. repens of M.
Lavallee's "Aboretum Segrezianum" and the Planera repens of foreign
catalogues generally are identical with the variety now mentioned under
the name it bears in the establishment of Messrs. Lee & Son.

[Illustration: FOLIAGE OF A FULL-GROWN ZELKOWA TREE.]

_Z. acuminata_ is one of the most useful and valuable of Japanese timber
trees. It was found near Yeddo by the late Mr. John Gould Veitch, and
was sent out by the firm of Messrs. J. Veitch & Sons. Maximowicz also
found the tree in Japan, and introduced it to the Imperial Botanic
Gardens of St. Petersburg, from whence both seeds and plants were
liberally distributed. In the _Gardeners' Chronicle_ for 1862 Dr.
Lindley writes as follows: "A noble deciduous tree, discovered near
Yeddo by Mr. J. G. Veitch, 90 feet to 100 feet in height, with a
remarkably straight stem. In aspect it resembles an elm. We understand
that a plank in the Exotic Nursery, where it has been raised, measures 3
feet 3 inches across. Mr. Veitch informs us that it is one of the most
useful timber trees in Japan. Its long, taper-pointed leaves, with
coarse, very sharp serratures, appear to distinguish it satisfactorily
from the P. Richardi of the northwest of Asia." There seems to be no
doubt as to the perfect hardiness of the Japanese Zelkowa in Britain,
and it is decidedly well worth growing as an ornamental tree apart
from its probable value as a timber producer. A correspondent in the
periodical just mentioned writes, in 1873, p. 1142, under the signature
of "C.P.": "At Stewkley Grange it does fairly well; better than most
other trees. In a very exposed situation it grew 3 feet 5 inches last
year, and was 14 feet 5 inches high when I measured it in November;
girth at ground, 8¾ inches; at 3 feet, 5 inches." The leaves vary in
size a good deal on the short twiggy branches, being from 3 inches to
3½ inches in length and 1¼ inches to 1½ inches in width, while those on
vigorous shoots attain a length of 5 inches, with a width of about half
the length. They are slightly hairy on both surfaces. The long acuminate
points, the sharper serratures, the more numerous nerves (nine to
fourteen in number), and the more papery texture distinguish Z.
acuminata easily from its Caucasian relative, Z. crenata. The foliage,
too, seems to be retained on the trees in autumn longer than that of the
species just named; in color it is a dull green above and a brighter
glossy green beneath. The timber is very valuable, being exceedingly
hard and capable of a very fine polish. In Japan it is used in the
construction of houses, ships, and in high class cabinet work. In case
99, Museum No. 1 at Kew, there is a selection of small useful and
ornamental articles made in Japan of Keyaki wood. Those manufactured
from ornamental Keyaki (which is simply gnarled stems or roots, or
pieces cut tangentially), and coated with the transparent lacquer for
which the Japanese an so famous, are particularly handsome. In the
museum library is also a book, the Japanese title of which is given
below--"Handbook of Useful Woods," by E. Kinch. Professor at the
Imperial College of Agriculture, at Tokio, Japan. This work contains
transverse and longitudinal sections of one hundred Japanese woods, and
numbers 45 and 46 represent Z. acuminata. It would be worth the while of
those who are interested in the introduction and cultivation of timber
trees in temperate climates to procure Kinch's handbook.

IDENTIFICATION.--Zelkova acuminata, D.C. Prodr., xvii., 166; Z. Keaki,
Maxim. Mel. biol. vol. ix, p. 21. Planera acuminata, Lindl. in Gard.
Chron. 1862, 428; Regel, "Gartenflora" 1863, p. 56. P Japonica, Miq.
ann. Mus. Ludg Bat iii., 66; Kinch. Yuyo Mokuzai Shoran, 45, 46. P.
Keaki, Koch Dendrol. zweit. theil zweit Abtheil, 427. P. dentata
japonica, Hort. P. Kaki, Hort.

[Illustration: FLOWERING TWIG OF PLANERA GMELINI.]

_Z. cretica_ is a pretty, small foliaged tree, from 15 to 20 feet in
height. The ovate crenate leaves, which measure from an inch or even
less, to one inch and a half in length by about half the length in
breadth, are leathery, dark green above, grayish above. They are hairy
on both surfaces, the underside being most densely clothed, and the
twigs, too, are thickly covered with short grayish hairs. This species,
which is a native of Crete, is not at present in the Kew collection; its
name, however, if given in M. Lavallee's catalogue, "Enumeration des
Arbres et Arbris Cultives à Segrez" (Seine-et-Oise).

[Illustration: OLD SPECIMEN OF ZELKOWA TREE IN SUMMER FOLIAGE,
CONCEALING FORM OF BRANCHING.]

IDENTIFICATION.--Zelkova cretica. Spach in Suit à Buff, ii, p. 121.
Ulmus Abelicea, Sibth & Sm. Prod. Fl., Graeca, i., p. 172. Planera
Abelicea Roem. & Schltz. Syst., vi. p. 304; Planch, in Ann. des Sc. Nat.
1848, p. 282. Abelicea cretica, Smith in Trans. Linn. Sov., ix., 126.

I have seen no specimens of the Zelkova stipulacea of Franchet and
Savatier's "Enumeratio Plantarum Japonicarum," vol. ii., p. 489, and as
that seems to have been described from somewhat insufficient material,
and, moreover, does not appear to be in cultivation, I passed it over as
a doubtful plant.

GEORGE NICHOLSON.

Royal Gardens, Kew.

       *       *       *       *       *




A NEW ENEMY OF THE BEE.


Prof. A.J. Cook, the eminent apiarist, calls attention to a new pest
which has made its appearance in many apiaries. After referring to the
fact that poultry and all other domestic animals of ten suffer serious
injury from the attacks of parasitic mites, and that even such household
stores as sugar, flour, and cheese are not from their ravages, he tells
of the discovery of a parasitic pest among bees. He says:

"During the last spring a lady bee-keeper of Connecticut discovered
these mites in her hives while investigating to learn the cause of their
rapid depletion. She had noticed that the colonies were greatly reduced
in number of bees, and upon close observation found that the diseased or
failing colonies were covered with the mites. So small are these pests
that a score of them can take possession of a single bee and not be
crowded for room either. The lady states that the bees roll and scratch
in their vain attempts to rid themselves of these annoying stick-tights,
and finally, worried out, fall to the bottom of the hive, or go forth
to die on the outside. Mites are not true insects, but are the most
degraded of spiders. The sub-class _Arachnida_ are at once recognized by
their eight legs. The order of mites (_Accorina_), which includes the
wood-tick, cattle-tick, etc., and mites, are quickly told from the
higher orders--true spiders and scorpions--by their rounded bodies,
which appear like mere sacks, with little appearance of segmentation,
and their small, obscure heads. The mites alone, of all the
_Arachinida_, pass through a marked metamorphosis. Thus the young mite
has only six legs, while the mature form has eight. The bee mite is
very small, not more than one-fiftieth of an inch long. The female is
slightly longer than the male, and somewhat transparent. The color is
black, though the legs and more transparent areas of the female appear
yellowish. All the legs are fine jointed, slightly hairy, and each
tipped with two hooks or claws."

As to remedies, the Professor says that as what would kill the mites
would doubtless kill the bees, makes the question a difficult one. He
suggests, however, the frequent changing of the bees from one hive to
another, after which the emptied hives should be thoroughly scalded. He
thinks this course of treatment, persisted in, would effectually clean
them out.

       *       *       *       *       *




CRYSTALLIZATION OF HONEY.


_To the Editor of the Scientific American_:

Seeing in your issue of October 13, 1883, an article on "Crystallization
in Extracted Honey," I beg leave to differ a little with the gentleman.
I have handled honey as an apiarist and dealer for ten years, and find
by actual experience that it has no tendency to crystallize in warm
weather; but on the contrary it will crystallize in cold weather,
and the colder the weather the harder the honey will get. I have had
colonies of bees starve when there was plenty of honey in the hives; it
was in extreme cold weather, there was not enough animal heat in the
bees to keep the honey from solidifying, hence the starvation of the
colonies.

To-day I removed with a thin paddle sixty pounds of honey from a large
stone jar where it had remained over one year. Last winter it was so
solid from crystallization, it could not be cut with a knife; in fact, I
broke a large, heavy knife in attempting to remove a small quantity.

As to honey becoming worthless from candying is a new idea to me, as I
have, whenever I wanted our crystallized honey in liquid form, treated
it to water bath, thereby bringing it to its natural state, in which
condition it would remain for an indefinite time, especially if
hermetically sealed. I never had any recrystallize after once having
been treated to the water bath; and the flavor of the honey was in no
way injured. I think the adding of glycerine to be entirely superfluous.

W.R. MILLER.

Polo, October 15.

       *       *       *       *       *




AN EXTENSIVE SHEEP RANGE.


The little schooner Santa Rosa arrived in port from Santa Barbara a few
days ago. She comes up to this city twice a year to secure provisions,
clothing, lumber, etc., for use on Santa Rosa Island, being owned by the
great sheep raiser A.P. Moore, who owns the island and the 80,000 sheep
that exist upon it. The island is about 30 miles south of Santa Barbara,
and is 24 miles in length and 16 in breadth, and contains about 74,000
acres of land, which are admirably adapted to sheep raising. Last June,
Moore clipped 1,014 sacks of wool from these sheep, each sack containing
an average of 410 pounds of wool, making a total of 415,740 pounds,
which he sold at 27 cents a pound, bringing him in $112,349.80, or a
clear profit of over $80,000. This is said to be a low yield, so it is
evident that sheep raising there, when taking into consideration that
shearing takes place twice a year, and that a profit is made off the
sale of mutton, etc., is very profitable. The island is divided into
four quarters by fences running clear across at right angles, and the
sheep do not have to be herded like those ranging about the foothills.

Four men are employed regularly the year round to keep the ranch in
order, and to look after the sheep, and during the shearing time fifty
or more shearers are employed. These men secure forty or fifty days'
work, and the average number of sheep sheared in a day is about ninety,
for which five cents a clip is paid, thus $4.50 a day being made by each
man, or something over $200 for the season, or over $400 for ninety days
out of the year. Although the shearing of ninety sheep in a day is the
average, a great many will go as high as 110, and one man has been known
to shear 125.

Of course, every man tries to shear as many as he can, and, owing to
haste, frequently the animals are severely cut by the sharp shears. If
the wound is serious, the sheep immediately has its throat cut and is
turned into mutton and disposed of to the butchers, and the shearer, if
in the habit of frequently inflicting such wounds, is discharged. In the
shearing of these 80,000 sheep, a hundred or more are injured to such an
extent as to necessitate their being killed, but the wool and meat are
of course turned into profit.

Although no herding is necessary, about 200 or more trained goats are
kept on the island continually, which to all intents and purposes take
the place of the shepherd dogs so necessary in mountainous districts
where sheep are raised. Whenever the animals are removed from one
quarter to another, the man in charge takes out with him several of the
goats, exclaims in Spanish, "Cheva" (meaning sheep). The goat, through
its training, understands what is wanted, and immediately runs to the
band, and the sheep accept it as their leader, following wherever it
goes. The goat, in turn, follows the man to whatever point he wishes to
take the band.

To prevent the sheep from contracting disease, it is necessary to give
them a washing twice a year. Moore, having so many on hand, found it
necessary to invent some way to accomplish this whereby not so much
expense would be incurred and time wasted. After experimenting for some
time, he had a ditch dug 8 feet in depth, a little over 1 foot in width,
and 100 feet long. In this he put 600 gallons of water, 200 pounds of
sulphur, 100 pounds of lime, and 6 pounds of soda, all of which is
heated to 138°. The goats lead the sheep into a corral or trap at one
end, and the animals are compelled to swim through to the further end,
thus securing a bath and taking their medicine at one and the same time.

The owner of the island and sheep, A.P. Moore, a few years ago purchased
the property from the widow of his deceased brother Henry, for $600,000.
Owing to ill health, he has rented it to his brother Lawrence for
$140,000 a year, and soon starts for Boston, where he will settle down
for the rest of his life. He still retains an interest in the Santa Cruz
Island ranch, which is about 25 miles southeast of Santa Barbara. This
island contains about 64,000 acres, and on it are 25,000 sheep. On
Catalina Island, 60 miles east of Santa Barbara, are 15,000 sheep, and
on Clementa Island, 80 miles east of that city, are 10,000 sheep. Forty
miles west of the same city is San Miguel, on which are 2,000 sheep.
Each one of these ranches has a sailing vessel to carry freight, etc.,
to and fro between the islands and the mainland, and they are kept busy
the greater part of the time.--_San Francisco Call_.

       *       *       *       *       *




THE DISINFECTION OF THE ATMOSPHERE.


At the Parkes Museum of Hygiene, London, Dr. Robert J. Lee recently
delivered a lecture on the above subject, illustrated by experiments.

The author remarked that he could not better open up his theme than
by explaining what was meant by disinfection. He would do so by an
illustration from Greek literature. When Achilles had slain Hector,
the body still lay on the plain of Troy for twelve days after; the
god Hermes found it there and went and told of it--"This, the twelfth
evening since he rested, untouched by worms, untainted by the air."
The Greek word for taint in this sense was _sepsis_, which meant
putrefaction, and from this we had the term "antiseptic," or that which
was opposed to or prevented putrefaction. The lecturer continued:

I have here in a test tube some water in which a small piece of meat was
placed a few days ago. The test tube has been in rather a warm room, and
the meat has begun to decompose. What has here taken place is the first
step in this inquiry. This has been the question at which scientific
men have been working, and from the study of which has come a valuable
addition to surgical knowledge associated with the name of Professor
Lister, and known as antiseptic. What happens to this meat, and what is
going on in the water which surrounds it? How long will it be before all
the smell of putrefaction has gone and the water is clear again? For
it does in time become clear, and instead of the meat we find a fine
powdery substance at the bottom of the test tube. It may take weeks
before this process is completed, depending on the rate at which it
goes on. Now, if we take a drop of this water and examine it with the
microscope, we find that it contains vast numbers of very small living
creatures or "organisms." They belong to the lowest forms of life, and
are of very simple shape, either very delicate narrow threads or rods or
globular bodies. The former are called bacteria, or staff-like bodies;
the latter, micrococci. They live upon the meat, and only disappear when
the meat is consumed. Then, as they die and fall to the bottom of the
test tube, the water clears again.

Supposing now, when the meat is first put into water, the water is made
to boil, and while boiling a piece of cotton wool is put into the
mouth of the tube. The tube may be kept in the same room, at the same
temperature as the unboiled one, but no signs of decomposition will be
found, however long we keep it. The cotton wool prevents it; for we may
boil the water with the meat in it, but it would not be long before
bacteria and micrococci are present if the wool is not put in the mouth
of the test tube. The conclusion you would naturally draw from this
simple but very important experiment is that the wool must have some
effect upon the air, for we know well that if we keep the air out we
can preserve meat from decomposing. That is the principle upon which
preserved meats and fruits are prepared. We should at once conclude that
the bacteria and micrococci must exist in the air, perhaps not in the
state in which we find them in the water, but that their germs or eggs
are floating in the atmosphere. How full the air may be of these germs
was first shown by Professor Tyndall, when he sent a ray of electric
light through a dark chamber, and as if by a magician's wand revealed
the multitudinous atomic beings which people the air. It is a beautiful
thing to contemplate how one branch of scientific knowledge may assist
another; and we would hardly have imagined that the beam of the electric
light could thus have been brought in to illumine the path of the
surgeon, for it is on the exclusion of these bacteria that it is found
the success of some great operation may depend. It is thus easy to
understand how great an importance is to be attached to the purity of
air in which we live. This is the practical use of the researches to
which the art of surgery is so much indebted; and not surgery alone,
but all mankind in greater or less degree. Professor Tyndall has gone
further than this, and has shown us that on the tops of lofty mountains
the air is so pure, so free from organisms, that decomposition is
impossible.

Now, supposing we make another experiment with the test tube, and
instead of boiling we add to its contents a few drops of carbolic acid;
we find that decomposition is prevented almost as effectually as by the
use of the cotton wool. There are many other substances which act like
carbolic acid, and they are known by the common name of antiseptics or
antiseptic agents. They all act in the same way; and in such cases as
the dressing of wounds it is more easy to use this method of excluding
bacteria than by the exclusion of the air or by the use of cotton wool.
We have here another object for inquiry--viz., the particular property
of these different antiseptics, the property which they possess of
preventing decomposition. This knowledge is _very_ ancient indeed. We
have the best evidence in the skill of the Egyptians in embalming the
dead. These substances are obtained from wood or coal, which once was
wood. Those woods which do not contain some antiseptic substance, such
as a gum or a resin, will rot and decay. I am not sure that we can
give a satisfactory reason for this, but it is certain that all these
substances act as antiseptics by destroying the living organisms which
are the cause of putrefaction. Some are fragrant oils, as, for example,
clove, santal, and thyme; others are fragrant gums, such as gum bezoin
and myrrh. A large class are the various kinds of turpentine obtained
from pine trees. We obtain carbolic acid from the coal tar largely
produced in the manufacture of gas. Both wood tar, well known under the
name of creosote, and coal tar are powerful antiseptics. It is easy to
understand by what means meat and fish are preserved from decomposition
when they have been kept in the smoke of a wood fire. The smoke contains
creosote in the form of vapor, and the same effect is produced on the
meat or fish by the smoke as if they had been dipped in a solution of
tar--with this difference, that they are dried by the smoke, whereas
moisture favors decomposition very greatly.

I can show why a fire from which there is much smoke is better than one
which burns with a clear flame, by a simple experiment. Here is a piece
of gum benzoin, the substance from which Friar's balsam is made. This
will burn, if we light it, just as tar burns, and without much smoke or
smell. If, instead of burning it, we put some on a spoon and heat it
gently, much more smoke is produced, and a fragrant scent is given off.
In the same way we can burn spirit of lavender or eau de Cologne, but we
get no scent from them in this way, for the burning destroys the scent.
This is a very important fact in the disinfection of the air. The less
the flame and the larger the quantity of smoke, the greater the effect
produced, so far as disinfection is concerned. As air is a vapor, we
must use our disinfectants in the form of vapor, so that the one may mix
with the other, just as when we are dealing with fluids we must use a
fluid disinfectant.

The question that presents itself is this: Can we so diffuse the vapor
of an antiseptic like carbolic acid through the air as to destroy the
germs which are floating in it, and thus purify it, making it like air
which has been filtered through wool, or like that on the top of a lofty
mountain? If the smoke of a wood fire seems to act as an antiseptic,
and putrefaction is prevented, it seems reasonable to conclude that air
could be purified and made antiseptic by some proper and convenient
arrangement. Let us endeavor to test this by a few experiments.

Here is a large tube 6 inches across and 2 feet long, fixed just above a
small tin vessel in which we can boil water and keep it boiling as long
as we please. If we fill the vessel with carbolic acid and water and
boil it very gently, the steam which rises will ascend and fill the tube
with a vapor which is strong or weak in carbolic acid, according as we
put more or less acid in the water. That is to say, we have practically
a chimney containing an antiseptic vapor, very much the same thing as
the smoke of a wood fire. We must be able to keep the water boiling, for
the experiment may have to be continued during several days, and during
this time must be neither stronger nor weaker in carbolic acid, neither
warmer nor colder than a certain temperature. This chimney must be
always at the same heat, and the fire must therefore be kept constantly
burning. This is easily accomplished by means of a jet of gas, and
by refilling the vessel every 24 hours with the same proportions of
carbolic acid and water.

The question arises, how strong must this vapor be in carbolic acid to
act as an antiseptic? It is found that 1 part acid to 50 of water is
quite sufficient to prevent putrefaction. If we keep this just below
boiling point there will be a gentle and constant rising of steam into
the cylinder, and we can examine this vapor to see if it is antiseptic.
We will take two test tubes half filled with water and put a small piece
of beef into each of them and boil each for half a minute. One test
tube we will hang up inside the cylinder, so that it is surrounded by
carbolic acid vapor. The other we stand up in the air. If the latter is
hung in a warm room, decomposition will soon take place in it; will the
same thing happen to the other cylinder? For convenience sake we had
best put six tubes inside the cylinder, so that we can take one out
every day for a week and examine the contents on the field of a
microscope. It will be necessary to be very particular as to the
temperature to which the tubes are exposed, and the rates of evaporation
beneath the cylinder. I may mention that on some of the hottest days of
last summer I made some experiments, when the temperature both of
the laboratory and inside the cylinder was 75°F. I used test tubes
containing boiled potatoes instead of meat, and found that the tube in
the air, after 48 hours, abounded not simply with bacteria and other
small bodies present in decomposition, but with the large and varied
forms of protozoa, while the tube inside the cylinder contained no signs
of decomposition whatever. When the room was cold the experiments were
not so satisfactory, because in the former case there was very little if
any current of air in the cylinder. This leads us to the question, why
should we not make the solution of carbolic acid and water, and heat it,
letting the steam escape by a small hole, so as to produce a jet? It is
a singular fact that for all practical purposes such a steam jet will
contain the same proportion of acid to water as did the original
solution. The solution can of course be made stronger or weaker till we
ascertain the exact proportion which will prevent decomposition.

From this arises naturally the question, what quantity of vapor must be
produced in a room in order to kill the bacteria in its atmosphere? If
we know the size of the room, shall we be able tell? These questions
have not yet been answered, but the experiments which will settle them
will be soon made, I have no doubt, and I have indicated the lines upon
which they will be made. I have here a boiler of copper into which we
can put a mixture, and can get from it a small jet of steam for some
hours. A simple experiment will show that no bacteria will exist in that
vapor. If I take a test tube containing meat, and boil it while holding
the mouth of it in this vapor, after it has cooled we close the mouth
with cotton wool, and set it aside in a warm place; after some days we
shall find no trace of decomposition, but if the experiment is repeated
with water, decomposition will soon show itself. Of course, any strength
of carbolic acid can be used at will, and will afford a series of tests.

There are other methods of disinfecting the atmosphere which we cannot
consider this evening, such as the very potent one of burning sulphur.

In conclusion, the lecturer remarked that his lecture had been cast into
a suggestive form, so as to set his audience thinking over the causes
which make the air impure, and how these impurities are to be prevented
from becoming deleterious to health.

       *       *       *       *       *




A NEW METHOD OF STAINING BACILLUS TUBERCULOSIS.

By T.J. BURRILL, M.D., Champaign, Ill.


Having had considerable experience in the use of the alcoholic solutions
of aniline dyes for staining bacteria, and having for some months used
solutions in glycerine instead, I have come to much prefer the latter.
Evaporation of the solvent is avoided, and in consequence a freedom
from vexatious precipitations is secured, and more uniform and reliable
results are obtained. There is, moreover, with the alcoholic mixtures a
tendency to "creep," or "run," by which one is liable to have stained
more than he wishes--fingers, instruments, table, etc.

From these things the glycerine mixtures are practically free, and there
are no compensating drawbacks. For staining _Bacillus tuberculosis_ the
following is confidently commended as preferable to the materials and
methods heretofore in use. Take glycerine, 20 parts; fuchsin, 3 parts;
aniline oil, 2 parts; carbolic acid, 2 parts.

The solution is readily and speedily effected, with no danger of
precipitation, and can be kept in stock without risk of deterioration.
When wanted for use, put about two drops into a watch glass (a small
pomatum pot is better) full of water and gently shake or stir. Just
here there is some danger of precipitating the coloring matter, but the
difficulty is easily avoided by gentle instead of vigorous stirring.
After the stain is once dissolved in the water no further trouble
occurs; if any evaporation takes place by being left too long, it is the
water that goes, not the main solvent. The color should now be a light,
translucent red, much too diffuse for writing ink. Put in the smeared
cover glass, after passing it a few times through a flame, and leave it,
at the ordinary temperature of a comfortable room, half an hour. If,
however, quicker results are desired, boil a little water in a test tube
and put in about double the above indicated amount of the glycerine
mixture, letting it run down the side of the tube, gently shake until
absorbed, and pour out the hot liquid into a convenient dish, and at
once put in the cover with sputum. Without further attention to the
temperature the stain will be effected within two minutes; but the
result is not quite so good, especially for permanent mounts, as by the
slower process.

After staining put the cover into nitric (or hydrochloric) acid and
water, one part to four, until decolorized, say one minute; wash in
water and examine, or dry and mount in balsam.

If it is desired to color the ground material, which is not necessary,
put on the decolorized and washed glass a drop of aniline blue in
glycerine; after one minute wash again in water and proceed as before.

Almost any objective, from one-fourth inch up will show the bacilli if
sufficient attention is paid to the illumination.--_Med. Record_.

       *       *       *       *       *




CURE FOR HEMORRHOIDS.


"The carbolic acid treatment of hemorrhoids is now receiving
considerable attention. Hence the reprint from the _Pittsburgh Medical
Journal_, November, 1883, of an article on the subject by Dr. George B.
Fundenberg is both timely and interesting. After relating six cases, the
author says: "It would serve no useful purpose to increase this list of
cases. The large number I have on record all prove that this treatment
is safe and effectual. I believe that the great majority of cases can be
cured in this manner. Whoever doubts this should give the method a fair
trial, for it is only those who have done so, that are entitled to speak
upon the question."

       *       *       *       *       *

A catalogue, containing brief notices of many important scientific
papers heretofore published in the SUPPLEMENT, may be had gratis at this
office.

       *       *       *       *       *




THE SCIENTIFIC AMERICAN SUPPLEMENT.

PUBLISHED WEEKLY.

TERMS OF SUBSCRIPTION, $5 A YEAR.


Sent by mail, postage prepaid, to subscribers in any part of the United
States or Canada. Six dollars a year, sent, prepaid, to any foreign
country.

All the back numbers of THE SUPPLEMENT, from the commencement, January
1, 1876, can be had. Price, 10 cents each.

All the back volumes of THE SUPPLEMENT can likewise be supplied. Two
volumes are issued yearly. Price of each volume, $2.50, stitched in
paper, or $3.50, bound in stiff covers.

COMBINED RATES--One copy of SCIENTIFIC AMERICAN and one copy of
SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00.

A liberal discount to booksellers, news agents, and canvassers.

MUNN & CO., PUBLISHERS,

261 BROADWAY, NEW YORK, N. Y.

       *       *       *       *       *




PATENTS.


In connection with the SCIENTIFIC AMERICAN, Messrs. MUNN & Co. are
Solicitors of American and Foreign Patents, have had 38 years'
experience, and now have the largest establishment in the world. Patents
are obtained on the best terms.

A special notice is made in the SCIENTIFIC AMERICAN of all Inventions
patented through this Agency, with the name and residence of the
Patentee. By the immense circulation thus given, public attention is
directed to the merits of the new patent, and sales or introduction
often easily effected.

Any person who has made a new discovery or invention can ascertain, free
of charge, whether a patent can probably be obtained, by writing to MUNN
& Co.

We also send free our Hand Book about the Patent Laws, Patents, Caveats.
Trade Marks, their costs, and how procured, with hints for procuring
advances on inventions. Address

MUNN & CO., 261 BROADWAY, NEW YORK.

Branch Office, cor. F and 7th Sts., Washington, D. C.










End of Project Gutenberg's Scientific American Supplement, No. 417, by Various