WIRELESS POSSIBILITIES




TO-DAY AND TO-MORROW SERIES


+DAEDALUS+, or Science and the Future

     By J. B. S. Haldane

+ICARUS+, or The Future of Science

     By Bertrand Russell, F.R.S.

+THE MONGOL IN OUR MIDST+, or Man and His Three Faces

     By F. G. Crookshank, M.C.F.R.C.P.

+WIRELESS POSSIBILITIES+

     By Prof. A. M. Low


In Preparation

     +TANTALUS+, or The Future of Man

     By F. C. S. Schiller


E. P. DUTTON & COMPANY




WIRELESS POSSIBILITIES

BY

A. M. LOW

_Late Hon. Asst. Professor of Physics
at the Royal Artillery College
Author of “The Two-Stroke Engine,” etc._

[Illustration: Logo]

_With four diagrams_

NEW YORK
E. P. DUTTON & COMPANY
681 Fifth Avenue




Copyright 1924
By
E. P. DUTTON & COMPANY

_All Rights Reserved_


Printed in the United States of America




TO
JOHN LOW




PREFACE


The effects of history upon the advance of science are often noted, but
the result of the march of progress is more often entirely neglected.

It would seem desirable that the future should be studied with
reasonable accuracy if we are to protect ourselves from the ill-effects
and obtain the benefit from the good fortunes of invention.

A.M.L.




WIRELESS POSSIBILITIES




INVENTION


Considering the very evident fact that we owe every detail of our
lives, every little comfort which separates us from the cave-man, to
the science of invention, it seems strange that so long should have
elapsed before this remarkable faculty received proper recognition.

Invention, in many ways, is the science and art of continuity of
thought. The inventor is often referred to as a strange person; very
true, very necessarily true when we realise that his doings must be
strange or new, to be of value. To train oneself to forget the smell
of the beefsteak when hungry and to continue the natural sequence of
ideas which may be passing through the mind, is to train the brain to
improve. If we can but sweep a crossing a very little cleaner than
that next to our own, perhaps we have surely accomplished one of the
greatest duties of all.

If not one day is spent without something learnt, surely we have
achieved the greatest object of work and enabled ourselves to realise
that there are no such things as basic facts.

Invention is not labour, for the latter is doing something we do not
wish to do in some one else’s time, and invention like all good things
is a work of love. Possibly that is why it is never paid!

We are too apt, I think, all of us, to rejoice in our greatness as
her devotees rejoiced in the greatness of Diana of the Ephesians: we
should realise every time we undress that we are little removed from
the animal, and that before many centuries have passed we shall be held
in almost universal contempt.

If that does not stir us to do our best, we are indeed a nation of
shopkeepers. But even the proprietor of the meanest store relies on his
powers of prophecy for his profits.

The science of wireless is but a few years old. We know about it little
more than our schoolboy sons, and in many cases not so much; let us
therefore be open-minded if we are still ignorant.

Commercial invention trusts too far to mass thinking: an original
mistake is very closely related to an accomplishment.




THE IMPORTANCE OF SOUND IN WIRELESS


A few lines of history are desirable here. I do not mean the history
controlled by the fact that William the Conqueror made many important
appointments in A.D. 1066 or that Stephen was particularly busy in
A.D. 1100. I mean the history of wireless, for, although Radio Science
is new, it has a history; all time is relative, and we ourselves are
functions of that phenomenon.

Only a few years ago the efforts of wireless experimenters were
entirely directed to the converting of the extremely delicate wireless
oscillation, still but little understood, into a mechanical movement,
in order that the motion of electrons in a problematical aether (which
may be nothing but a thought projection and which may exist in many
different forms) might be altered into something readable by a man with
a check waistcoat and a stock and share list in his hand.

That particular use, and the information that one army is about to kill
another could be transmitted to headquarters, naturally occurred to
everyone as the first valuable applications of Radio.

The many devices, the electro-magnetic receivers, tape machines,
coherers, syphon recorders and the thousand and one electrical machines
produced at the time for these purposes, have practically all gone.

Even when to-day we want to send messages quickly, we record them upon
a Dictaphone and rely almost entirely upon the sense of hearing.

Sound, the regular oscillation, and noise, the irregular oscillation,
of the air, are really the beginning and end of wireless as it is known
to the public to-day.

I would go further when thinking of the public. They do not want to sit
with a telephone upon their heads, even if their ears may be improved
thereby. They require to walk into a drawing-room, and having stood
for a moment upon the mat, they must be able to cross the room, touch
a button in a fretwork cabinet, and by the movement of a lever be
able to place themselves in touch with any part of the world. Paris,
Hong-Kong, London, all must be one to them if we are to get their money
for our art.

In other words, we are compelled to use what we now designate the “loud
speaker.” We have got to project a sound into the room before we can
sell our instruments, and therein lies one great difficulty.

In the first place we dare not exaggerate the movements of a delicate
telephone very much or we shall spoil it--therefore we construct
something which looks very much like a magnified telephone with a
trumpet upon it. The mechanism is naturally rather heavy as regards the
moving parts. In order to vibrate these heavy parts with the aid of
our aetherial oscillations we have to amplify the available current,
and during this process we naturally spoil the detail, or, in other
words, we magnify it so much that electrical distortions occur through
the whole range of various transformers and other items sold by every
shop in the world--at double their value.

Most people are not content with a gentle sound: they find it necessary
to express their joy at having reached their home by dancing;
consequently they want plenty of sound, and they do not mind if it
turns into noise.

They will tell you boldly that their wireless set with a couple of
dozen foreign-made valves can be heard right across a large street,
a street by the way in which we still permit as much nerve-shattering
noise to occur as is thought necessary. This means that we must
have quite a big movement on a diaphragm of large size, and a large
diaphragm is made to move by the electrical oscillation, itself not
very accurate; naturally, if it is heavy, like a poker or anything
else, it has a will of its own, and therefore it continues to move when
the wireless oscillation has told it to stop. It does not even commence
to move when it is told to do so, as it would were it a thin delicate
telephone diaphragm from which accurate music can be obtained.

This means further distortion, and so bad is it that a great many
people say plainly that they will only listen to wireless concerts
through a telephone and that they will only use crystals to obtain
rectification because of the inaccuracies otherwise unavoidable to-day.

But this is not business, because do not forget we must have our
cabinet with a fern upon it and beautiful music, if we are to be
successful. Business always leads science, as we know.

Now think why it is that we need this big diaphragm moving so hard to
get a big noise; let us neglect electrical details and consider what
produces the noise; or sound, if we are lucky.

Sound is unfortunately purely a mechanical phenomenon as we chiefly
understand it, and is produced by oscillations, alternate compression
and rarefaction of the atmosphere. Unlike the aether, which sometimes
oscillates only too readily, air is a heavy material and has great mass.

You will soon find this out if you put your head out of a railway
carriage window, because the air is so heavy that we have got to really
kick it and hit it hard before we can obtain a reasonable degree of
noise.

When a speaker is standing at one end of a room, irrespective of what
he says, the actual temperature-rise of the air can be measured, a fact
which was used during the war for the inspection of sound.

Sound is a very complicated thing. It can be reflected in much the same
way as light, and I suppose most school-boys know that if a concave
mirror is at one end of a room and a similar mirror at the other with
a watch hanging at its focus, the watch cannot be heard by an observer
walking across the room, yet as soon as he places his ear at the focus
of the other mirror he will hear the tick clearly, showing that sound
is easily reflected. Everybody who has heard an echo should know this.

Sound travels also very slowly, and there is plenty of time for wind
and different mechanical scraping effects to spoil the purity and
partially absorb its delicacies.

[Illustration: Fig. 1. Sound can be focussed by a concave reflector and
by this means the tick of a watch can be heard at a distance. The watch
and the end of the wooden rod are placed at the focus of the reflector.]

Remember that if I am addressing a man by wireless who is one hundred
miles away, someone who is listening on a telephone will hear my voice
before I am heard at the end of the big hall where I am speaking,
because the velocity of sound is only 1100 feet per second, and
wireless, like light, travels much faster. Sound can also be actually
refracted. Just as the old-fashioned jeweller used a globe of water to
concentrate the light upon his work, so will a collodion balloon filled
with carbon dioxide, the ordinary gas product of average combustion,
act as a lens for sound, which can be actually focussed by these means.

This exemplifies the complication of our subject, and indicates that
the heavy diaphragm and other details of the loud speaker must produce
serious distortion.

Let us be honest at once. We can only hear such distant places as
America by the grace of heaven. Even Sunlight can tune sweet song into
vague cracklings. Until true tuning can be obtained we are largely at
the mercy of the reproducing instrument, which too often exaggerates
every fault and gives the impression that wireless and music are in no
way related. No loud speaker of to-day really produces voice and song
which sound exactly like voice and song. It all too much resembles a
bad gramophone, but without the advantage of the user having the choice
of the music.

If user and manufacturer would concentrate upon obtaining purity, if
they would try the effects of damping upon loud speakers, which are
easily obtained; if they would realise that the horn of the loud
speaker should be without resonance, that it should be also damped
and pocketed, that its goose-necked shape is not adopted without an
object, and if they would aim at the delivery of true music instead
of noise--then, we should make a great advance. The average loud
speaker can often be greatly improved by padding the horn with some
kind of tape, and as an example of the great difficulties of proper
transmission let it be made quite clear that with most cases of
wireless communication the sending is nearly perfect. Reception is
greatly at fault: it is the reception that mangles the sound and makes
it too often almost unbearable to anybody of reasonably sensitive
hearing.

At some large transmission stations it was at one time quite common to
use three separate microphones for the modulation. One received notes
of high pitch, one of low, and a third attempted to obtain the “S”
sound with the result that, when this “S” microphone was adjusted for a
man who did not say his “S” very loudly and someone appeared who did,
it sounded exactly as if the speaker had dropped his false teeth.

All this is now avoided. The ordinary diaphragm is no longer in use,
but a very small coil of aluminium wire is suspended between the poles
of an electro magnet, allowed to rest against an ordinary pad of
cotton wool, and that is all!

The infinitesimal movements of this aluminium coil will reproduce
speech up to about 40,000 periods per second in oscillatory speed, yet
speech is well recognisable if all frequencies over 4,000 per second
are gridded out.

How difficult it is going to be to make a large, heavy, and rapidly
moving diaphragm reproduce accurately when we have had to take all
these precautions to obtain accuracy of transmission! It is not
impossible; it will come one day.

Now let us see what is the result of our sound troubles.

We are told that before long it will be quite easy to hear birds
singing in trees and the waves beating against the seashore. Quite
right, quite easy to do it now, but if a bird singing in a tree sounds
like a man moving his condenser or walking about with a pair of squeaky
boots, is it progress?

[Illustration: Fig. 2. If light falls on a very thin diaphragm carrying
a mirror, the sound waves being directed into it by a trumpet can be
photographed upon a revolving sensitised film.]

Perhaps it is. The whole point of wireless is that it brings a man into
your room, but it must sound like the man himself if it is to be really
effective; it is this pitiful quality of reproduced sound that has
wrecked the talking cinema.

It is very easy to photograph sounds and to reproduce them
simultaneously with the projection of a picture, but to reproduce
all the sounds of a cowboy scene accurately is, at present, almost
impossible. If a hero says “Good-bye” to a heroine with a kiss like
a creaking board, in the middle of a twenty-reel drama, instead of
improving upon the effect of your imagination, which tells you that it
is real, and which acts the scene for you better than it can be shown
in life or sound, it would be like putting up a blackboard across the
screen with the words written upon it, “this is not real--it is only
a fake.” That is what is wrecking the talking cinema. As a scientific
proposition it is easy, but the results are not good enough at present,
and, if we can improve, let us first consider the loud speaker.

The talking cinema will come as a matter of course. It is so easy to
record sounds upon the film by photography with reproduction by the
selenium cell or the neon tube; it is easy to photograph the wave;
it is easy actually to impress the sound wave upon the film with the
picture, or to use a gramophone; but reproduction is not like a human
voice. Neither as yet is any reproduction ever like the voice itself.
Let that painful fact be remembered.

Unfortunately, from the business point of view, the long distance
reproduction effect is usually satisfactory even when re-broadcasted
upon telephones, and for business purposes it is immaterial whether the
voice that records the profit or loss is harsh or pleasant.

So the greatest effects we shall soon see from wireless and sound
are these: we shall be able to speak to people all over the world by
relaying and a combination of land-line and radio; we shall easily be
able to connect our office with a wireless station on the coast, radio
across the Continent, and then connect by land-line to another office
on the other side of the Atlantic.

All this is so easy that no one can doubt that we shall soon listen in
to native jamborees; no one can doubt that we shall hear the strange
cries of partisans at a baseball match taking place a few miles from
New York; no one can question these things, and when reproduction
becomes so accurate that the very nature of the people is revealed to
us through their speech, surely we might be a little more neighbourly
even with those whom we now pretend to love? Relations are notoriously
quarrelsome.

If you are in a concert hall and the number of people is varied,
it will alter the effect of the sound. You have only to look at a
sound-wave photograph produced from a violin to realise from its dainty
intricacies that the least variation of any of its harmonics or the
very exact shape of its wave beats will reveal all the difference
between a beginner and the finest musician in the world. But these
things are seldom noticed in wireless.

It is quite easy to photograph a sound, by means of a diaphragm beside
which a soap bubble is thick, and to compare wireless sound with the
original; even then we have the great difficulties of resonance, and a
diaphragm cannot reproduce properly. How, therefore, dare we neglect
the dreadful sounds we hear in the name of radio music?

If a piece of silvering, one thirty-secondth of an inch, be scraped
from the back of a mirror and fastened to the outer part of a celluloid
diaphragm (made by water-floating a drop of amyl acetate in which
celluloid has been dissolved), it only requires a horn and a beam of
light to render visible the waves of sound. A diaphragm movement of a
millionth of a millionth of an inch is sometimes audible.

It is the science of wireless that is beautiful; it is the
possibilities that are wonderful; but to talk of pure sound and to
judge of it by the human ear which varies after every meal, is like
measuring the amount of current passing through an electric-light bulb
by feeling its heat with the hand.

It is not generally known that, during the War, experiments were made
with a sound-reflector for listening to different types of aeroplane
and submarine, by means of a microphone placed at the centre of a
concave mirror. The difficulty was that of distortion, which is the
whole source of trouble with sound producers to-day. Distance is
no difficulty and when we can obtain purity and realism as well as
distance, the latter is no difficulty at all; then only will be the
time when we shall have that spontaneous mental realism of vision that
will help radio to alter the world.

In a few years time we shall be able to chat to our friends in an
aeroplane and in the streets with the help of a pocket wireless set,
and be able to do practically everything by the aid of radio that we
now do with our voice.

The only thing that will seem intensely strange will be that these
comforts never existed before!




WIRELESS INACCURACIES


I have often wondered whether people realise that broadcasting, at
present, is only possible or, shall I say is only popular, because of
its extreme impracticability for most forms of secret communication.

Supposing two people had been able to converse privately and with
absolute secrecy from other “listeners in,” then we should not mind
trusting all our messages to Radio. At present, what can be coded can
be decoded, and we are not entranced by the idea of entrusting our
pennies to the winds of Heaven and the vagaries of a thunderstorm.

If wireless had really been selective in the first instance,
broadcasting would not have been its initial phase.

Wireless at present is excessively inefficient; a few yards from a
large broadcasting station the power is measured in millionths of a
horse-power, is disseminated in all directions, and is almost without
definite selectivity.

When the day comes when we can tune with absolute accuracy; when we
can combine waves with accuracy and obtain a directional beam with the
shortest waves for re-broadcasting purposes, then we shall obtain real
happiness from the results.

Parliament must have its special wave length, the divorce courts of
the future will be broadcasted to prevent people from catching cold by
waiting outside. It will be quite easy for the Judge, at a doubtful
passage, to press a switch and to say, “I think we will cut that out.”

One can imagine broadcasting of the future linking up every city from
China to London; one can see special wave lengths for men, and equally
special wave lengths for women. And we shall forget the time when ships
at sea with ancient sets interfere with the murdering of music by the
local amateur.

It has been said that, at present, those in authority find it necessary
to choose special voices for the wireless broadcast-delivering. What
an idea! The public want to hear everybody. They want to have local
events broadcast, irrespective of the operator. They do not want a
perfect voice, they want a perfect personality, and it is rather the
wireless that must be altered to take any reception than the human
voice whose very characteristics delight us.

We are too accustomed to relying upon our senses. We are apt to think
that the ear is most delicate. It is nothing of the kind; it cannot
even hear notes that delight the heart of a dog, and if one pictures
life with the brain of a man, the ear of an antelope, and microscopic
eyes, together with the nose of a dog, some little idea of the
inefficiency of those few senses which we slightly understand can be
obtained.

To live in any town would be impossible: the smells of Bond Street
instead of pleasing the dog would tell us of rotting animal matter and
alarm us to distraction. We could never sit down upon a beautiful piece
of grass without listening to the worms and imagining ourselves with
them. We could not bear to drink water for the peculiar bodies we would
see in it. The wind in the trees, the people walking down our street or
into our rabbit-warrens of flats, would sound like a battle from afar.

It is only a question of relative senses, easily tested by anyone
who has the patience to fit an effective microphone to the amplifier
purchased in mahogany case at the local “store.”

Wireless inaccuracies abound; anyone who hears its music will agree,
but what of their effect upon our bodies!

The air, popularly speaking, must now be full of radio oscillations,
and if you tell me that they are negligible in effect I may believe
you, but if I hear there is no effect at all, I know that it cannot be
true.

It is more than likely that, in the far future, the proper study
of oscillatory theories, the proper investigation of the spectrum
only very partially explored by a few, will lead us to a better
understanding of the nature of life, and will help us to appreciate
the theories of electrical sonics. Theories of preventing local
thunderstorms, of growing babies and wheat effectively, by electrical
or other similar oscillatory means, of helping ourselves to see by
wireless and of affecting our health at the end of many generations for
the better, may all be developed in the time to come.

If some health effect is produced, why should we not try to render it
beneficial? A small effect can be very cumulative in nature. One has
only to inspect a human nail to agree with that statement.




RADIO TELEVISION


It has been said of sound that a bell never ceases to echo and that the
human voice never ceases when once words are spoken; truly, it is an
alarming thought when the nature of most of our sayings is realised.

Not long ago it was claimed that by means of a delicate microphone
the sayings of Henry VIII had been investigated--though nature of the
subject was, with not less delicacy, omitted.

Much the same basic ideas apply to light except that we are dealing
with a very much more interesting phenomenon, one indeed which is
not apparently too material and a sense which gives us nearly all our
nonphysical sensations.

We actually transmit very few senses: we merely convert their nature
by utilising different portions of the spectrum. Light has undoubtedly
its tone values, as in the case of sound, and it has not yet been
definitely established with what portion of the body vision is actually
obtained. It is likely that light is projected along the electro lines
of force by the movement of electrons but whether the ether consists
of electrons themselves, whether it exists in many forms, or is merely
a result of the mass effect of thought, we do not yet know. Light
very possibly proceeds from the eye as well as from the luminous body
concerned.

The science of Radio has taught us something of light, but only to
a modest extent, for light yet remains one of the most inefficient
factors of a civilisation which almost entirely depends upon it for
existence.

There is a strange factor which we may call the “Law of Supply and
Demand.” This strongly implies the faculty of invention, a facility of
“wishfulness to improve”; something far better than the necessity for
invention. Let us remember that our clothes are not necessities; they
are merely comfortable, and it is comfort that distinguishes us to-day
just as it is convenience that will in the future give us a life which
will be better by far than that experienced by the kings and princes of
to-day.

Civilisation has depended almost entirely upon the speeding up
of communication. We can travel fast; we can convey our thoughts
at great speed, but, unfortunately, although all these means of
intercommunication are devised with the one idea of preventing
physical work and of obviating the movements of our gross bodies, our
senses are very closely combined. It is consequently not possible to
ring up somebody on the wireless telephone, a fact itself easy of
accomplishment, and to impress our personality upon the listener. This
is simply because we require a combination of senses for hearing,
seeing, smelling, and other reactions, in order to convey our whole
personality.

Vision at a distance is, therefore, very necessary as our inclination
for travel decreases and its comfort increases.

It is also important from the point of view of “speeding up,” which
we have no reason to suppose will cease. All operations have steadily
increased in speed for many generations.

There was a time when we made appointments to meet our friends at the
full of the moon, but now we say at “10 o’clock, and I can only give
you two minutes.” In the future we shall probably say, “Meet me at
10.2.1-5 secs., and do not keep me waiting.” To do this we must have
radio sight.

Many years ago, when experiments were made on the subject, the usual
cry appeared from what I always mentally typify as the “Flat Earth
Brigade”; they said, “Impossible.” What would our forebears have said
of talking to a man in an aeroplane? “Impossible!” It is a foolish
word. Now all over the world experiments are being conducted, many of
them with success and some with the guarantee of reasonable success in
twenty years or less.

Now wireless, if I may apply the word here, is very like light in many
ways; it is capable of refraction and shadow effects; it travels at the
same speed, and if the wave-lengths of wireless could be sufficiently
shortened to become visible we should probably find ourselves with a
new, and possibly effective, method of transmitting wireless light and
even power.

Radio is a phenomenon of the spectrum like ordinary photographic light,
X-rays, and so on. It is effects which determine the difference to our
eyes of things invisible, solid, and transparent.

It may well be that, when we succeed in inter-planetary communication,
we shall discover that the inhabitants see by the X-ray, by wireless,
or by heat.

It is not difficult to obtain a proportionate interchange of radio
and light oscillations. Even sunlight affects wireless telegraphy,
and experiments which have been conducted upon the carrying and
directional power of certain other rays and oscillations have not
been entirely without results. We may, one day, obtain far greater
sensitivity of direction, greater carrying power, from small initial
output with a degree of selectivity almost infinite, in comparison with
modern working.

To use a light beam along which we can talk, to use a light beam
initially and to turn it into light when required, is by no means
difficult; it suggests the direct method of wireless vision, but from
the mechanical aspect the problem is still less complicated. The
difficulties of Radio Television to-day are constructional; in the far
future it may be a question of pure physics.

There is, at least, one simple method of sending photographs
by wireless with a reasonable degree of accuracy. Distance,
re-broadcasting, relaying are, none of them, of any great technical
importance. Interference is certainly a difficulty, for in the case of
a picture the eye cannot distinguish between faults so easily as the
ear can automatically separate unpleasant noises from music.

If an ordinary photograph is transferred to a copper plate, either
flat or round, and a contact finger is allowed to pass over it,
clearly the resistance between the plate and the finger will vary with
the thickness of the photographic film. If this resistance is used
to modulate the transmission in place of an ordinary microphone for
speech, the current at the receiving end can be picked up, amplified,
and used to mark darkly, lightly, or not at all, upon a prepared piece
of paper which is affected by the passage of an electric current.

By these means good photographs can be reproduced, and doubtless in the
future we shall be able to sign our cheques by the rapid transmission
of motion; we shall be able to trace criminals, send out their
finger-prints, and carry on very many classes of business which, at
present, require our bodily attention.

[Illustration: Fig. 3. If light passes through the negative to be
transmitted on to a selenium cell which modulates in place of a
microphone, the wave can be picked up, amplified, and made to open or
close a shutter. This permits another light to record, spot by spot,
the reproduction of the original photograph.]

What a help to the man who objects to a large city. Why could he not
conduct his business from his house in comfort instead of having his
spats washed every week in order to maintain his financial reputation?

There is a still more rapid method of transmitting a photograph: it is
to allow the light from an ordinary lamp to pass through a spot upon
the negative and then to a selenium cell. Selenium is so constituted
that its resistance to the passage of electricity varies with the
amount of light to which it is exposed. This property has been used to
light up and to extinguish ordinary street lamps, for demonstration
purposes.

If a selenium cell is used in place of the ordinary broadcasting
microphone, the transmission can be modulated in accordance with the
passage of the light through a black spot on the negative, such as part
of a top hat, or a white spot, such as a white face or part of it.

The received current is picked up and amplified in the ordinary manner,
but instead of operating a diaphragm to produce speech, it is taken
to a kind of electrically operated venetian blind, which allows light
to pass through it or not to pass through it, in accordance with the
transmitting current.

It requires little imagination to see that, if a beam of light is
allowed to pass through each point of the original negative in turn,
the final picture can be built up from “spots” somewhat in the manner
of a half-tone block.

It takes a long time, is rather patched, and is liable to interference;
but the whole process is perfectly simple. Consider the great
importance of this experiment to Radio Television.

The human eye sees only one point at a time but in the fact that
instantaneous vision of a complete picture is not necessary lie our
hopes of television to-day.

The eye is a very defective piece of mechanism considered from an
optical standpoint. The pointed rays which appear to come from stars
show one example of faulty optical construction, however wonderful
may be the whole structure. Another property, and a feature of great
importance from the aspect of television, is that of retentivity.

We all know that when a lighted cigarette is whirled round in the hand
the result appears to be a ring of fire. Our brain assures us that
the eye is telling lies and that it is really a moving point. This is
because the image is impressed and actually lasts upon the eye or its
retina.

This phenomenon is used in every cinematograph; without it the ordinary
film would not be practicable. Each picture of an arm about to light a
cigarette shows the arm constantly closer and closer, and before one
picture has had time to die out the other is thrown upon the screen.
The result is an illusion of motion.

To return to the transmission of a photograph, let us imagine that it
is sent in a series of spots beginning in the top left-hand corner at
12 o’clock: the bottom spot will probably be completed, at modern
sending speeds, by about 12.15, in the case of a picture two inches
square.

Clearly all we have to do is to reduce this time to 4/5 of a second
altogether, and we shall be again sending the first spot before it has
had time to die away from the apparent vision of the observer. In other
words, we will see by wireless.

The obvious method of assisting in this speeding up of sending the
thousands of spots, would be to graduate them by some means of rotary
conversion or to decrease the number of spots. The latter is one method
by which practical television can be accomplished to-day.

[Illustration: Fig. 4. If a photograph is divided into spots and the
last be sent only 4/5 sec. after the first, television can be obtained;
but if the spots must be large to do this, only such items as the
difference between a cross and a circle can be observed.]

It would be quite easy to fix up an apparatus by means of which
we could show whether an office in New York was lit up or not,
the observer being situated in London. This is a form of energy or
combination of phenomena which amounts to wireless sight, but it does
not help us to see shapes or forms or to say if the light is from a
candle, the sun, or an arc lamp.

By increasing the number of cells from one to, let us say, twenty, we
could possibly indicate the difference between the moving shadow of a
cross or a circle, but to radiate detail is a very difficult problem,
which doubtless will be partially solved within the next few years. The
electro-magnetic theory of light and the phenomena exhibited by the
neon tube, present many opportunities.

What an excellent invention this will be! It means that a telescopic
camera could be attached to an aeroplane and the views seen by
thousands in a cinematograph theatre who may have the pleasure of
witnessing the finish of a horse-race and knowing without loss of time
how much money they have lost.

It would mean that the crew of a ship, a submarine in difficulties, or
the passengers in an aeroplane, might be visible to people many miles
away. It could not yet occur without their wish, for the transmitting
apparatus must first be put into operation.

The senses of seeing and hearing are possibly amongst the most
important of all, and, if we can convey both of them to a distance, it
means that we can call friends, nations, music, and personalities to
our fireside, by the touching of a button.

Such possibilities need no enlargement. Wireless may prove a far more
rapid link than the ordinary increase of travelling speed and may help
nations to intermingle to the common good.

The question of seeing in colours has hardly yet been considered, but
that also will come to us, however great the difficulties may appear
to-day.

Certainly Leagues of Peace will have more arguments, and Generals will
have more weapons.

The laziest millionaire to-day, in a physical sense, will be
hard-worked in comparison with the fortunate individual of the
scientific future. We will travel in the best possible manner and in
such comfort that the mind will be free to receive impressions. Our
main objective will be to train it for that purpose.

After all, what more can we do now?




WIRELESS AND WAR


The subjects of War and Wireless cover a multitude of closely allied
ills.

It is only natural that wireless should first have been applied to Love
and War. I remember well one of the most remarkable applications of
wireless mentioned in the press in the early days was that of a cable
sent to an unfortunate man in mid-ocean, informing him that an all too
successful arrival of twins had taken place.

War is, of course, a natural process a little less educated, and more
unkind, in consequence, than birth control.

Most inventions are first applied to the science and art of warfare.
Perhaps we should not regard this as all to the bad, for War has a
remarkable capacity for acceleration.

Development of the wireless valve was greatly assisted by the War: the
aeroplane, the art of plastic surgery, and many other human benefits
have arrived more rapidly from the same cause.

Let us see, therefore, what wireless can do now, and what it may
accomplish for the future of organised destruction.

Mentally, the fittest should survive, in both the realms of invention
and physiology. It is only a few years since wireless was of no
intrinsic value for ordinary land warfare, by virtue of the fact that
interference was extremely easy, and that any coded message could be so
easily decoded.

At present wireless messages are chiefly of service where secrecy is
not of such importance as speed; but an enormous number of experiments
are being conducted upon beam wireless, directional wireless, and in
the combination of the Radio oscillation with some other oscillations
such as those of visible or invisible light. By these means secrecy
will be obtained when we discover how to use small powers for long
distance, but at present Radio is chiefly of value as a time-saver.

The pilot in an aeroplane can talk to his base: he will soon be able
to write and transmit vision from a plane which could be controlled
by wireless. The time will come when low-flying wireless planes will
explore, and render visible at many miles distant, places where no
human pilot could remain for any length of time in safety.

It is not long ago that we rejoiced because a damaged ship was able to
call for help by wireless, but we have only to look back to a recent
war to remember an occasion when one ship was totally unable to call
assistance because its wireless was jammed. In other words, enemy
interference was possible.

This should show us how far we have yet to go in an utterly new and
very little understood science.

We began with sparks, we progressed to coherers, and now we have
valves; but let it not be thought for a moment that the valve
represents finality to any thinking being.

Broadcasting at present has really become so universal only on account
of the exceedingly public nature of wireless, for, when we are able
to obtain accuracy of tuning and direction, we shall not only use the
latter to guide ships at sea, but we shall have correspondence which
can be conducted with a reasonable degree of secrecy. We shall have
special wave-lengths for the Government, special wave-lengths for
Parliamentary debates, and the Divorce Courts. We shall not conduct
our conversations in such a manner that any schoolboy with a piece of
wire, a needle, and some sugar, can promptly listen in.

The very idea suggests a new “Peeping Tom.”

As far as communication is concerned, we shall have whole armies in
instantaneous touch with each other: it may indeed make real secrecy
more difficult. It should always be recollected that when we refer
to wireless speech, wireless control, and Radio Vision, we do not
necessarily mean the same form of electrical wave by which we now
broadcast a comic opera.

It is with oscillation that we are really concerned, and we may
discover many forms of electronic vibration at present occupying
portions of the so-called spectrum which are as yet very little
understood.

It may be impossible for the Commander-in-Chief of the future to
conceal a document from the eyes of wireless; and who knows but that
the electrical operation of thought may be reduced to a science so that
our very ideas are not secret without protection?

How many of us to-day could risk all our thoughts being known? It would
probably improve moral standards if they were published: science tends
to effect an average improvement.

We have never yet really seen the extraordinary value of wireless in
war. If we had solved the problem of selection, the transference of
speech by phonograph records dropped from aeroplanes would never have
arisen.

Undoubtedly, we shall see wireless controlled tanks, submarines,
and torpedoes on both land, air, and water. All will be accurately
controlled, and they will possibly be able to find their way home and
to operate from a distance while out of sight.

Even to-day it is possible for an aeroplane to operate a torpedo, to
steer it properly, to slow it down; and for a pilot of an aeroplane
many miles away to work his will upon it with a reasonable degree of
accuracy and with the help of a gyro control.

The day will undoubtedly come when the problem of defending an island
is not that of the mainland itself but of all its dependencies.

No large town could live for long if it were bombed from a distance by
wireless, if gassed and poisoned from a distance, were it not for the
balance of protection and defence which is usually maintained by nature.

We shall in the future, see forms of electric death and heat-rays which
may materialise not as a direct projection of heat but as some form of
oscillation which produces heat only when striking a metallic object.

We have been so often told that power can be transmitted by Radio that
we are apt to look upon this statement with contempt. This is quite
wrong: power will one day be transmitted by wireless; power can at
present be inductively sent over quite a large air gap, though the
energy available quite close to any wireless station is practically
negligible to-day.

When motor-cars and ships are controlled or stopped by wireless, it is
not the wireless which does the work; the therial oscillation merely
sends signals to the ordinary operative mechanism.

Much excitement has been caused by the alleged injury of aeroplanes and
motor-cars by wireless, but how is it that they can afterwards proceed?
Do we forget that the petrol engine has to be restarted, and that, if
allowed to fire when a car was in gear, it might be damaged and would
probably not operate the moving parts?

If wireless power could be directed in such a form that it could be
conveyed along a wave of “atomic” oscillation, many more valuable ends
might be served than the enforced landing of aeroplanes.

Our clocks could be corrected by wireless, experiments could be
conducted upon the nature of light and ether in various forms. We might
decide the mode of propagation of light and thought, and investigate
the apparent motion of the electron along the electro lines of force.

What an opportunity for study to the man of medicine! What a chance
to find out how the oscillations of life are connected with those we
partially understand.

What a chance for the burglar to discover the presence of hidden
spoons as a mass of metal by means of wireless; what a chance for the
surveyor and the seeker after oil to use this all-prevailing sense of
oscillation and even to discover the meaning of radiation.

Oscillation--that is all we mean by Radio; and oscillation is at the
base of life itself. It will not be long before travellers by air,
land, and water, will be no longer alone.

That they will be able to converse with their homes may seem no
advantage, but that they can remain in touch with the rest of mankind
is most obviously desirable.

If this were understood to-day, I should not need to make noises
with my lips or require the simulacra of these noises to be
produced upon paper to convey my thoughts. If thought is a process
of energy-conversion--and who will deny it?--what form of screening
prevents its use, and why should its reception be confined eventually
to life upon this particular and very troublesome planet?

It is remarkable how little is known of wireless: the very simplicity
of its painfully standardised features is a trap for the unwary. It
is a universal science, but we do not yet know the correct diaphragm
size for a loud speaker, nor how damping should be employed. The finest
apparatus is available to all, and yet we do not understand the fullest
range of wave-lengths. The study of radio-active materials and short
wave radiation may in one day produce the cold-emitter valve, abolish
the outside aerial, and bring to our closer understanding some of the
many senses now so atrophied in mankind, that we can only speculate as
to their existence. I doubt much if the schoolboy of the future will
greatly esteem the radio expert of this century.