MARVELS OF THE RAILOPHONE

WH4.T THE WIRELESS TELEPHONE WILL DO. '

In view of the extraordinary number, of terrible railway accidents that have occurred in different parts of the world during the last few months, the latest invention in the science of wireless, electricity deserves far more public attention than has been given to it. , When, eight months ago, there were published the first details of a new , system of telephoning to and from trains in rapid motion, only, a few business men were keenly interested in the invention. To them the "railophone," as it was called, appeared a novel and valuable luxury --rlike trains with stenographers arid typists—which would enable them to . conduct their ■ business while they were travelling between the great centres of industry. Now, however, the scope of the invention has teen wonderfully ex-1 tended. It" promises to create a beneficial revolution in railway traffic by making a train the safest as well as the most comfortable means of travelling. As soon as the "railophone" comes, into general use a collision between two trains will practically be an impossibility. Moreover, the difficult art of the signalman will be .transformed. : into a science. The reach and flexibility of the arm of the law will be marvellously extended to the. detriment of Wrongdoers flying i'rom justice; and a passenger on an English express, while travelling along at6C milesi an hour, will soon be able to hold a quiet conversation with a person as far away as Astrakan. Mr Hans yon Kramer, the inventor of the "railophone," is an electrical engineer of Birmingham. He has worked on the old idea of electro-magnetic induction discovered by Faraday about 80 years ago. Electricity is a thing with many strange properties. If, for instance, a coil of wire is charged with _ it. and then placed near another coil, the latter will, in certain circumstances, also become active with the electric purreiit. There is a radiation of electric force, so to speak, from the charged wire to tho empty wire. TJlib phenomenon will easily be underStood by comparing it with the phenomenon, of megnetism. The magnet a I/tracts a piece of iron by an induction of magnetic force from the magnet to the iron. In both cases the effect is "wireless." The principle of induction is an extraordinary on«; it underlies the working of all dynamos and electric motors. No one, however, seems to have gone on to apply it to the purposes of wireless telephoning until Mr yon Kramer took up the difficult problem. The inventor made his discovery while experimenting for something else. Rontgen rays had lately been discovered, and he hit upon the idea of passing electric waves through a brick wall with the object of trying to see through the interventing barrier. As he was winding a very large coil for this purpose one day, he found that an unusually large amount of electric power was passing through the brick wall, and. was being picked up by another coil of wire on the other side. He at once fitted a telephonic apparatus to" the two wires, and found that he could pass sound waves { through walls six feet in thickness.

This was an entirely different thing from the principle of sending electric waves in fierce, lightning-like pulsations through the air, as done by Marnoni's system. Mr yon Kramer aimed oiily. at collecting in empty wire an electric emanation from a charged wire at a distance of a few

feet. In this he succeeded. But his achievement did not seem very romarkabale until he proceeded to put it to practical uses. He worked out a way of telephoning from room to room, without wires, while moving the instruments at will. And, what was stiU more promising, he fitted a frame coil to a motor-car, and laid on the track a ground wire connected with a telephone at his works. While the car was running at 40 miles an hour induction was established .between the frame coil and the group wire, and a conversation, was easily carried on between the occupants of tho car and the persons,at the works. So excellent were the results that the London, Brighton, and South Coast railway iitted a carriage with Mr yon Kramer's apparatus, and had a ground wire laid down on their line. Two coils of wire were fixed round the carriage. One of these was charged by means of an electric battery, and provided with a telephonic speaking instrument. The emanations from the current created in the train were picked up by the ground wire lying on v the earth between the rails. There was an openair space of l&in between the carnage coil and the ground wire, but the current passed by wireless induction from the train to the ground wire. Then there was another wire on the earth which was charged with the primary current set up by persons speaking on the telephone at London and signal-boxes along the route. These currents were also reproduced by "wireless induction" in the second coil round the railway carriage. This second coil was connected with the receiving apparatus of the telephone. By means of it the passengers were able to listen to the words of their remote friends, while the railway officials on the train conversed with unseen signalmen. Thus>, by means of the transmitting and receiving coils, messages were sent and delivered while, the train'was moving at the rate of 40 miles, an hour. All this, however, only represented the first stage in the development of wireless telephony.- The "railiphone" in the last eight months has been greatly improved The system is being now installed, in a more perfected* form, on the stratford-011-Avon and1 Midland Junction railway. Visitors travelling on the line to ths festival will find the "raityphdne" in working order, and" be able to test some of its wonderful qualities. But the most useful of its application will not come under their direct observaitipn. Not only will every train be wirelessly connected with the whole telephone system, but each engine will be linked to all the ■sigual-boxesi it passes; and—the most important of tlie improvements— every train will be in automatic communication with the trains nearing it. As soon as two trains-approach so closely as to be in the "danger jzone" a, wireless telephonic circuit will be established between them, and bells will automatically warn the enginedrivers to avoid collision.

Moreover, to make assurance doubly sure, all the trains will be linked b yelectric currents to the signal- , boes/ Each signalman, will have bej neath his hand 'a special apparatus for transmitting,'a loud signal. This ; will be sent' alond the ground wire, and, by wireless induction, received by the second coil on the train. Then, by, means of the other first primary lire coil fixed round the train, messages will be sent to the signal-boxes. All signalmen and engine-drivers will thus be in continual communication. The present clanger of dense fog and blinding snows preventing signals from being seen, will be obviated ; and the railway officers! will possess, such large powers of controlling the arrival .and despatch of trains as will enable them probably toy arrange for a quicker service, while abolishing all chance of collision. For not only does the "railoplume" set bells clanging in trains within the "danger zone," but it warns the signalmen in the nearest signal-box; Still more marvellous is the latest improvement which Mr yon Kramer has made to his system. It is now possible, for a signalmen to apply automatically a brake to a train without any regard to what the en-gine-driver is doing. Further, a train which is overtaking another may be stopped dead by a brakeaction worked by the train in front of it. It" will thus be seen that the "railophone" not only adds a luxury to travelling, but revolutionises oomplgtely the control of railway traffic.