ELECTRIC MESSAGES, ETC.
The telegraphic wire in the home and street will fulfil a very
important part in the economy of the twentieth century. For conveying
intelligence, as well as for heating, cooking and lighting, the
electric current will become one of the most familiar of all the
forces called in to assist in domestic arrangements. The rapidity with
which the electric bell-push has taken the place of the old-fashioned
knocker and the bell-hanger's system affords one indication of the
readiness with which those forms of electric apparatus which are
adapted to all the purposes of communicating and reminding will
recommend themselves to the public during the twentieth century.
In another direction the eagerness with which every advance in the
telephone is hailed by the people may well offer an augury of rapid
progress in the immediate future. In this department invention will
aim just as much at simplification as at elaboration; and some of the
pieces of domestic electrical apparatus universally used during the
twentieth century will be astonishingly cheap.
The call to awake in the morning will, in cities and towns, be made by
wireless telegraphy, which will also be used for the purpose of
regulating the domestic clocks, so that if desired any suitable form
of clock alarm may be used with the most perfect confidence. A
tentative system of this kind has been adopted in connection with
certain telephone exchanges, in which special officers are told off
whose duty it is to call those subscribers who have paid the small fee
covering the expense. These officers are required to time their
intimations according to the previously expressed wishes of
subscribers. This kind of service, as well as the regulation of the
household clock, is eminently a department of domestic economy in
which wireless telegraphy will prove itself useful, because it does
not demand that a subscriber shall have gone to the expense of
installing a wire to his house and of paying a rent or fee for the use
of one.
The clock controlled by wireless telegraphy will doubtless undergo a
rapid development from the time when it is first introduced.
Practically the same principles which enable the electrician to
utilise the "Hertzian waves," or ether vibrations, for the purpose of
setting a clock right once a day, or once an hour, will permit of an
impulse, true to time, being sent from the central station every
second, or every minute, and when this has been accomplished it will
be seen that there is no more use for the maintenance of elaborate
clockworks at any place excepting the central station. The domestic
clock will, in fact, become mainly a "receiver" for the wireless
telegraphic apparatus, and its internal mechanism will be reduced,
perhaps, to a couple of wheels, which are necessary to transmit the
motion of a minute-hand to that which indicates the hours.
The fire-alarm of the future must be very simple and inexpensive in
order to ensure its introduction, not only into offices and warehouses
but also into shops and houses. The fire-insurance companies will very
shortly awake to the fact that prompt telegraphic alarm in case of
fire is worth far more than the majority of the prohibitions upon
which they are accustomed to insist by way of rendering fires less
likely. The main principles upon which the electric fire-alarm will be
operated have already been worked out and partially adopted. In the
system of fuses and cut-outs used in connection with electric
lighting, the methods of preventing fire due to the development of
excessive heat have been well studied. But simplification is
particularly required in the case of those fire-alarms which are to be
useful for giving intimation of a conflagration from any cause
arising.
As the telegraphic and telephonic wires are extended so as to traverse
practically all the streets of every city, the fire-insurance
companies will find it to their advantage to promote a simple plan,
depending on the use of a combustible thread passing round little
pulleys in the corners of all the rooms and finally out to the front,
where an electrical "contact-maker" is fixed, so that on the thread
being burnt and broken at any point in its circuit, an electric
message will be at once sent along the nearest wire to the
fire-brigade station and a bell set ringing both inside and outside
the premises.
Somewhat similar systems will be used for checking the enterprises of
the burglar. The best protected safes of the future will be enmeshed
in networks of wires encased in some material which will render it
impossible to determine their positions from the outside. These wires
will be so related to an electric circuit that the breaking of any
one of them, at any part of its course, will have the effect of
ringing a bell and giving warning at the police station, as well as at
other places where potential thief-catchers may be on hand. For doors
and windows very simple contact devices have already been brought out,
but the principal objection to their general adoption arises from the
fact that so very many houses remain unconnected with any telephone
system which may be made available for calling the police. Even were
all houses connected it is true that in some instances attempts might
be made to cut the wires when a raid was in contemplation, but the
risk of discovery in any such operation would prove a very powerful
deterrent. In fact the telephone wire, more than any other mechanical
device, is destined to aid in "improving" the burglar out of
existence.
With the indefinite multiplication of telephone subscribers at very
cheap rates, there will come a powerful inducement towards the
invention of new appliances for rendering the subscriber independent
of the attention of officers at any central exchange. The duty of
connecting an individual subscriber with any other with whom he may
desire to converse is, after all, a purely mechanical one, and
eminently of a kind which, by a combination of engineering and
electrical skill, may be quite successfully accomplished. In the
apparatus which will probably be in use during the twentieth century,
each subscriber will have a dial carrying on its face the names and
numbers of all those with whom he is in the habit of holding
communication. This will be his "smaller dial," and beside it will be
another, intended for only occasional use, through which, by
exercising a little more patience, he may connect himself with any
other subscriber whatever. Corresponding dials will be fixed in the
central office.
Under this system, when the subscriber desires to secure a connection,
he moves a handle round his dial until the pointer in its circuit
comes to the desired number. An electrical impulse is thus sent along
the wire to the central station for every number over which the
pointer passes, and the corresponding pointer or contact-maker at the
central station is moved exactly in sympathy. When the correct number
is reached the subscriber is in connection with the person with whom
he desires to converse. If, however, the latter should be already
engaged, a return impulse causes the bell of the first subscriber to
ring. Of course the prime cost of installing such a system as this
will be greater than in the case of the simple hand-connected
telephones; but the two systems can be used conjointly, and the
immense convenience, especially to large firms, of being able to go
straight to the parties with whom they wish to communicate, will
induce many of them to adopt the automatic apparatus as soon as it has
been perfected.
Wireless telephony must come to the front in the near future, but at
first for only very special purposes. The prospect of the profits that
would be attendant on working up a business unhampered by the heavy
capital charges which weigh upon the owners of telephone wires must
stimulate inventive enterprise to a remarkable degree in this
particular line. The main difficulty, however, in the application of
the system to general purposes will lie in the need for an ingenious
but simple means for enabling one subscriber to call another.
For this purpose probably the synchronised clock system already
referred to will be found essential, each office or house being
furnished with a timekeeper of this type kept in constant agreement
with a central clock, and so arranged that only when the ethereal
electrical impulse is given at a certain fixed point in the minute,
will any particular subscriber's bell be rung. This may be effected
by some such arrangement as a revolving drum, perforated at a
different part of its periphery for each individual subscriber, and
capable of permitting the electrical contact which makes a magnet and
rings the bell only at the fraction of a moment when the subscriber's
slot passes the pointer.
This will mean, of course, that only at a certain almost
infinitesimally small space of time in the duration of each minute
will it be possible to call any particular subscriber, or rather to
release the mechanism which will set his bell ringing for perhaps a
minute at a time. In the presence of unscrupulous competition,
resulting in the flinging out of Hertzian wave vibrations
promiscuously, for the purpose of destroying a rival's chances of
obtaining satisfactory connections, it would be necessary to make
rather more complicated arrangements of a nature analogous to those of
the puzzle lock. Instead of one impulse during the minute, two or
three would be required, in order to release the mechanism for ringing
any subscriber's bell; and no ring would take place unless the
time-spaces between these impulses were exactly in accordance with the
agreed form, which might be varied at convenient intervals.
Yet in the cases in which wireless telephony and telegraphy are taken
up by local public authorities having power to forbid any one playing
"dog in the manger," by preventing useful work by others while failing
to promote it himself, the simpler system of wireless telephone call
will be practicable. With the advance of municipalisation, and of
intelligent collectivism generally, enterprises of public utility will
be guarded from mere cut-throat commercial hostility much more
sedulously in the twentieth century than they have been in the past.
A great multitude of new applications of the telegraphic and
telephonic systems will be introduced in the immediate future. Not
only will those subscribers who are connected by wire with central
stations have the advantage of being called at any hour in the morning
according to their intimated wishes, but such services as lighting the
fires in winter mornings, so that rooms may be fairly warmed before
they are entered, will be performed by electric messages sent from a
central station.
Drawings will also be despatched by telegraph. For such purposes as
the transmission of sketches from the scene of any stirring event, the
first really practical application of drawing by telegraph will
probably depend upon the use of a large number of code words divided
into two groups, each of which, on the principles of co-ordinate
geometry, will indicate a different degree of distance from the base
line and from the side line respectively, so that from any sketch a
correct message in code may be made up and the drawing may be
reconstructed at the receiving end. Illustrated newspapers will in
this way obtain drawings exactly at the same time as their other
messages, and distant occurrences will be brought before the public
eye much more vividly and more correctly than has ever hitherto been
practicable.
For special objects, also, photographs can be sent by telegraph
through the use of the photo-relief in plaster of Paris, or other
suitable material, which travels backwards and forwards underneath a
pointer, the rising and falling of which is accurately represented by
thick and thin lines--or by the darker and lighter photographic
printing of a beam of light of varying intensity--at the other end, so
that a shaded reproduction of the photograph is produced. Relief at
the sending end is in this way translated into darkness of shade at
the receiving end. Any general expansion of this system, if it comes,
will necessarily be postponed till long after the full possibilities
of the codeword plan have been exploited, because the latter works in
exactly with the ordinary methods for sending telegraphic matter.
The keen competition between submarine and wireless telegraphy will be
one of the most exciting contests furnished by electrical progress in
the first quarter of the new century. Attention will be devoted to
those directions on the surface of the globe in which it is possible
to send messages almost entirely by land lines, and to bridge over
comparatively small intervals of space from land to land by wireless
telegraphy. Thus the Asiatic and Canadian route may be expected
shortly to enter into competition with the Atlantic cables in
telegraphic business to the United States; while Australia will be
reached _via_ Singapore and Java.
A great impetus will be given to the wireless system as a commercial
undertaking when arrangements have been perfected for causing the
receiver at any particular station to translate its message into a
form suitable for sending automatically. When this has been done, many
of the wayside stations will be almost entirely self-working, and
messages, indeed, may be despatched from island to island, or from one
floating station to another across the Atlantic itself.
Another requirement for really cheap telegraphy on the new system is
a more rapid method of making the letters or signals. The irregular
intervals at which the sparks from the coil of the transmitter fly
from one terminal to the other render it impossible to split up the
succession of flashes into intervals on the dot-and-dash principle,
without providing for each dot a much longer period of time than is
required for the transmission of messages on land lines. In fact the
need for going slowly in the sending of the message is the principal
stumbling-block which disconcerts ordinary telegraphic operators when
they come to try wireless telegraphy. For remedying this defect the
most hopeful outlook is in the direction of a multiplication of the
pieces of apparatus for spark-making and the combining of pairs of
them in such a way that, whenever the first one fails during an
appreciable interval of time to emit a spark, the second is called
into requisition. In this way a constant stream of sparks may be
ensured, without incurring the risk of running faster than the coil
will supply the electrical impulses necessary for the transmission of
the message.
Increased rapidity in land telegraphy by the ordinary system of
transmission by wire, and facility in making the records at the
receiving end in easily read typewriting--these are two desiderata
which at the close of the nineteenth century have been almost
attained, but which will take some time to introduce to general
notice. In the commercial system of the twentieth century the
merchant's clerk will write his messages on a typewriter which
perforates a strip of paper with holes corresponding to the various
letters, while it sets down in printing, on another strip, the letters
themselves. The latter will be kept as a record, but the former will
be taken to the telegraph office and put through the sending machine
without being read by the operator. The message will print itself at
the other end and wrap itself up in secret, nothing but the address
being made visible to the operator.
For the use of the general public who are not possessed of the special
apparatus necessary to perforate the paper another system is
available. Sets of movable type may be provided at the telegraph
office in small compartments, the letters being on one side and
indentations corresponding to the required perforations being cut or
stamped into the other sides of the movable pieces. The sender of a
message will set it up in a long shallow tray or "galley" like those
used by printers, and he will then turn the faces of the letters
downwards and see the whole passed through the machine without being
read by the operator; after which he can distribute the letters if he
chooses. In this way telegraphy will gradually become at once far more
secret and far cheaper than it is at present, and a large amount of
correspondence which at present passes through the post will be sent
along the wire.
Many merchants will have their telephonic apparatus fitted with
arrangements for setting up type or perforating strips of paper, as
already described; and also with receiving apparatus for making the
records in typewriting. If they fail to find a subscriber or
correspondent on hand at the time when he is wanted, they can write a
note to him which he will find hanging on a paper strip from his
telephone when he returns. Another mode of accomplishing a somewhat
similar result is to provide the telephone receiver itself with a
moving strip of steel, which, in its varying degrees of magnetisation,
records the spoken words so that they will, at some distance of time,
actuate the diaphragm of the receiver and emit spoken words. The
degree of permanency which can be attained by this system is, of
course, a vital point as regards its practical merits.
Still unsolved electrical problems are the making of a satisfactory
alternate current motor suitable for running with the kind of
currents generally used for electric lighting purposes--the
utilisation of the glow lamp having a partial vacuum or attenuated gas
for giving a cheap and soft light somewhat on the principle of the
Geissler tube--and last, but not least, the direct conversion of heat
into electricity.
With regard to the first-mentioned, the prospects have been materially
altered by a discovery announced at the New York meeting of the
American Association for the Advancement of Science within a few weeks
of the close of the nineteenth century. The handy and effective
alternate current motor indeed seemed then as far distant as it had
been in 1896, when Sir David Salomons remarked, in his work on
_Electric Light Installations_ (vol. ii., p. 97): "No satisfactory
alternate current motor available on all circuits exists as yet,
although," he added later, "the demand for such an appliance increases
daily". It seems, however, that electricians have been looking in the
wrong direction for the solution of using the same wire for alternate
current lighting and for motive power at the same time. Professor
Bedell, of Cornell University, announced at the New York meeting
referred to his discovery of the important fact that when direct and
alternate currents are sent over the same line each behaves as if the
other were not there, and thus the same line can be used for two
distinct systems of transmitting electrical energy. No time will be
lost in putting this announcement to the test, not only of scientific
but also of practical verification, and the probability is that all
electric lighting stations in the twentieth century will contain not
only dynamos of one type for the supply of light, but also direct
current generators for transmitting power in all directions over the
same cables.
The glow lamp having no carbon filament, but setting up a bright light
with only a fraction of the resistance presented by carbon, would, if
perfected, render electric lighting by far the cheapest as well as the
best method of illumination. Tentative work has indicated a high
degree of probability that success will be achieved, and the glowing
bulb is at any rate a possibility of the future which it will be well
to reckon with.
In reference to the conversion of heat into electricity without the
intervention of machinery to provide motion, and thus to cause
magnetic fields to cross one another, very little promise has yet been
shown of any fundamental principle upon which a practical apparatus of
the kind could be based. The electrician who works at this problem
has to begin almost _de novo_, and his task is an immensely difficult
one, although on every ground of analogy success certainly looks
possible. In the meantime, as has already been indicated, the steam
turbine and dynamo combined, working practically as a single machine
for the generation of electricity, offers practically the nearest
approach to direct conversion which is yet well in sight.