Wireless Telegraph Within This Year

Tesla Promises ’Round the World With no Wire.

FOR COMMERCIAL USE

Inventor Says Emphatically That He Has the Necessary Financial Backing — The Instruments and the Mode of Operation.

New York Sun.

Shortly after the New Year Nikola Tesla announced that having spent many of the later years of the nineteenth century in electrical experiments and investigations he proposed giving to the world in the early years of the twentieth century some of the results in practical and commercial form of these experiments and investigations. Two weeks ago he brought out his “sanitary light,” as he calls it. Yesterday he announced through the Sun that the wireless telegraph — his system of the wireless telegraph — would be at the world’s service in about eight months. By this system messages are to be transmitted to any distance on the earth’s surface. Some of the machinery is now being constructed, and for the rest of it contracts will soon be awarded.

The chief essentials of Tesla’s system are a transmitter and a receiver, with the earth, rather than wires, as the connecting medium. Both transmitter and receiver are rather simple machines, or, at any rate, look so on his patents. The transmitter, which is set up at one point, receives the electrical energy from the source of power, intensifies it and sends it through a wire into the earth, through which it passes away in all directions. At a distant point from the transmitter, say in London, for instance, a receiver is set up. This is adjusted so that its vibrations are in unison with the vibrations of the transmitter. Being “in tune,” as Tesla calls it, the receiver catches up from the earth the currents from the particular transmitter, magnifying them many thousand times.

The cost of telegraphing by the wireless system will, Tesla says, be much less than by the cable system and messages may be sent much more quickly. Through the use of certain artifices it will be made impossible for a receiver in Calcutta, for instance, to take up the currents carrying a message from New York to London; and in time of war, one belligerent will not be able to interfere with, or take advantage of, the messages of the other belligerent.

Just where the first wireless telegraph office will be opened in New York Tesla does not care to tell at present. As for the financial end of the enterprise that has been privately arranged, and the inventor was most enthusiastic yesterday in his veiled references to the financial assistance he has received. In telling of the satisfactory outcome of his work on his wireless telegraph system and of his future plans in regard to putting it to commercial use, Mr. Tesla made the following statement to a Sun man:

“I am quite surprised at the lively interest manifested in my announcement to the Sun that I am about to begin the construction of my plants for telegraphy without wires across the Atlantic. I have been steadily at work on the problem for seven years, and from time to time the advances I have made in the perfection of my apparatus have been noted. Three years ago I had so far progressed as to undertake the transmission with confidence, and had I been myself a wealthy man, I would have certainly attempted it. But I had to depend on financial help from others, and before I could conscientiously approach any one, I had to settle all doubt in my own mind as to the outcome of the experiment. This was one of the reasons for my going to Colorado, where, after eight months of investigation and perfection of my transmitters and receivers, I satisfied myself that, with my system, I could not only transmit messages across the Atlantic, but also across the Pacific ocean.

“Three distinct experimental evidences of the practicability of my plan were obtained, each of which would have been sufficient to inspire me with confidence of success. One of these evidences was my discovery of the stationary electrical waves in the earth, which I have already published, and which demonstrates in a positive manner that vibratory currents can be transmitted through the terrestrial globe just as through a wire to the greatest distances. Another evidence I obtained by ascertaining the law of variation of the intensity of the effects produced by my transmitter at a distance, which enables me to design the transmitting apparatus for the required performance, just as I can construct a dynamo or steam engine for a given output. The third evidence I obtained by actual measurements of the intensity of the effects through varying distances of from 650 to 700 miles, and this was what may be considered the proof of the pudding.

“The greatest difficulties were encountered in the development of the transmitting apparatus, for not only was it necessary to produce impulses of enormous intensities, but they had to have certain characteristics to make them best suitable for the purpose. Another great trouble was to perfect methods for securing complete privacy and non-interference of messages, for only after this was assured could I hope to make a wireless transmission to a great distance a practical success. It is quite easy to tune a circuit, but ordinary artifices were not adequate to giving that degree of safety against extraneous disturbance which was necessary, and a number of new expedients had to be resorted to. These have now been so far perfected that the same privacy is practicable as in transmission over a private wire.

“Another feature of great importance in the commercial exploitation of the system was the simultaneous transmission of a number of messages by the same apparatus, and in this direction I was fortunate enough to find a happy solution, enabling results to be attained which had been heretofore impossible.”

“What is meant by tuning of circuits?” Mr. Tesla was asked.

“Expressed in popular terms, tuning is the process of adjusting the vibrations of one circuit to those of another. The vibration is chiefly dependent on two quantities, which are designated as capacity and inductance, and in the coarse adjustment either one of these or both may be varied to give to the vibration the pitch required. But finer touches are necessary to insure the best success, and one might say that there is just as much difference between ordinary tuning, according to book instructions, and artistic tuning, as there is between a barroom picture and a painting by Sargent.”

“What must a company operating with your system have, in order to transmit messages, for instance, from New York to London?” asked the Sun man.

“The stations at either side will have to have transmitting and receiving apparatus, which, in substance, will be as I have described in my patents on energy transmission without wires. The essential part of the transmitter is a circuit, which is connected to the ground at one of its ends and to a conducting surface at the other end, and which is carefully adjusted so as to respond freely to the vibrations of the primary source of currents. Under these conditions currents of enormous intensities are produced in the circuit, which pass away through the ground in all directions. The circuit acts just like a pump in an ocean, drawing out and pumping in water rhythmically, creating ripples, which spread, in ever widening circles, over the surface of the sea. Suppose the transmitter in New York is controlled by the key of the operator. Each time he depresses the key these ripples spread over the globe and reach London, where a receiving circuit arranged and connected similarly, may be located. This receiving circuit is tuned with the greatest care to the vibrations of the transmitter, and just as a heavy pendulum is set swaying by weak impulses properly timed, so the receiving circuit is excited, the received impulses being thus magnified many thousand times. By this process impulses which would be in themselves inadequate to affect the receiving instrument, are rendered perceptible.”

“You say that the currents from the transmitter pass through the earth in all directions. If that be true, then at any point on the earth’s surface where a receiver is set up, those currents may be caught and messages received. Is that correct?”

“That, generally speaking, is true, but no message can be caught or read except by those receivers which are designed for the purpose. As I have stated before, I have perfected this part of my system to such a degree that to read a message at some other place than that for which it is intended will be well nigh impossible. Obviously, any number of receiving stations may be provided, which will respond to definite signals or notes of the transmitter as, for instance, in the transmission of time to the astronomical observatories, in weather reports, or the like, for which purposes I have devised a special apparatus.”

“In time of war could the telegrams sent by one belligerent to a distant point be caught up by receivers stationed in the possessions of the other belligerent, or in any way interfered or tampered with?”

“In such case still more rigorous measures would be adopted to exclude the possibility of the messages being read by others and I have evolved some plans which would make the privacy absolute. The best the enemy could do would be to set up a powerful transmitter at the most effective place and try to muddle up the messages, but in such case, again, his maneuver would be without avail, if certain provisions be adopted.”

“How about the length of time consumed in transmitting messages by your system as compared with that through the cables?”

“The transmission will be much quicker than through the cables, because the latter are handicapped by what is known as electrostatic capacity. A number of schemes have been proposed to overcome this drawback, but all I have so far examined are entirely inoperative.”

“In the actual transmission of messages may the same apparatus in the way of keys and receivers be used as is employed in telegraphing over cables, and may the Morse code be used?”

“In the beginning I propose to resort to the instruments now used, but I have some plans in this regard which I hope will enable me greatly to increase the speed. The Morse code may, of course, be used.”

“Are these plants to be simply experimental or are they to be commercially used? If for commercial use, when do you expect them to be in operation?”

“Most emphatically they are intended for commercial use. I have finished my experiments. I estimate that the work will consume about eight months, but I am prepared to encounter some delays and drawbacks, which always turn up somehow. You know, of course, that this is an engineering undertaking which requires special machinery and a variety of appliances, most of which are novel.”

“Where are your first plants to be located?”

“I have determined the site on this side; the other is still under consideration. I prefer not to dwell on these details at present.”

“What will be the cost of transmitting messages by your wireless system as compared with the cost of sending messages by the present cables?”

“Of course, it will be much cheaper; first, because of the relatively small cost of the apparatus, and secondly because of the greater speed of transmission. The greater the distance the greater will be the advantage of the wireless transmission over the cables.”

Mr. Tesla was asked whether the new system was to be exploited commercially by a company, by himself alone or by himself and a few friends. He said in reply that this will be wholly left to the judgment of those who furnish the capital. He did not believe in the inventor being his own business manager.