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 vi 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.