Nikola Tesla's Revolution in War Telegraphy

Nikola Tesla’s Revolution in War Telegraphy

He Believes He Will Be Able to Successfully Operate Without Wires from a Ship 100 Miles Away

New York, April 30. Nikola Tesla has made an instrument for telegraphing without wires by which a vessel a hundred miles from our coast will be able to send messages to the shore. Mr. Tesla tells me that he is ready to offer this invention to the Government for use in war. Its advantages are easy to understand. There has been much talk of telephoning to moving ships and some discussion of the feasibility of sending out a cable repair ship to pick up one of the great ocean cables and send us messages telling of the approach of an enemy.

The telephoning would be over a short range and the cable ship would be confined to observation along the line of cable communication. The wireless telegraph would enable any ship within 100 miles of a coast station to send messages to the shore. The ships of a feet lying off Havana could receive their instructions from the Navy Department by way of Key West and telegraph to Secretary Long and the President just what was happening in Cuba.

Mr. Tesla is not prepared to make public the details of his invention. He always gives his conclusions to the world through articles in a scientific periodical, which he writes with the utmost care. But he said to me yesterday: “You may say that I have succeeded in making machine a thousand times more powerful than any ever made before. With it I expect to send messages without wires over long distances - probably 100 miles.”

I asked Mr. Tesla if, his invention was so near perfection that it might be of use in the war with Spain.

“I think so,” he said. “If it can be used, I have no desire for compensation. It is not for sale. But I will freely offer it to the Government. One reason I cannot tell you just what my machine is, is that if it can be used on our ships it will give us an advantage: and I shall be proud to have been of so much use to my country.”

“Then you, consider yourself a good American, Mr. Tesla?”

The inventor threw up his hands and looked incredulous at the suggestion of doubt.

“I a good American?” he said. “I was a good American before I ever saw this country. I had studied its government; I had met some of its people. I admired America. I was at heart an American before I thought of coming here to live.”

“What opportunities this country offers a man! Its people are a thousand years, yes, a thousand years, ahead of the people of any other nation of the world. They are big, broad-minded, generous. I could not have accomplished in any other country what I have done here. I was in France for a time. I tried to work out some of my ideas there. But I could get no encouragement. I could find no one to back me. When I came here, I met men immediately who were ready to help me to develop my ideas. The American people are quick to hold out a helping hand and to give recognition. Yes, I am as good an American as there is. I have nothing to sell to the Government of the United States. If it needs my services in any way it is welcome to them.

“Of this invention I can tell you that it is the result of more than five years of hard work. The experiments, which have been carried on in Europe and which have attracted so much comment, follow the lines that I laid down some years ago. For a long time the experiments abroad did not follow these lines, and they were not successful. Signals could be sent, but only short distances. When they returned to my system they found that they could send messages to a much greater distance.

“Five years ago in the course of a lecture, speaking of the transmission of intelligible signals or perhaps even power to any distance without the use of wires, I said: ‘I am becoming daily more convinced of the practicability of the scheme; and though I know full well that the great majority of scientific men will not believe that such results can be practically and immediately realized, yet I think that all consider the development in recent years by a number of workers to have been such as to encourage thought and experiment in this direction. My conviction has grown so strong that I no longer look upon this plan of energy or intelligence transmission as a mere theoretical possibility, but as a serious problem in electrical engineering, which must be carried out some day.

“The idea of transmitting intelligence without wires is the natural outcome of the most recent results of electrical investigations. Some enthusiasts have expressed their belief that telephony to any distance by induction through the air is possible. I cannot stretch my imagination so far, but I do firmly believe that it is practicable to disturb by means of powerful machines the electrostatic condition of the earth and thus, transmit intelligible signals and perhaps power.

In fact, what is there against the carrying out of such a scheme? We now know that electric vibration may be transmitted through a single conductor Why then not try to avail ourselves of the earth for this purpose? We need not be frightened by the idea of distance. To the weary wanderer counting the mile posts the earth may seem very large, but to that happiest of all men, the astronomer, who gazes at the heavens and by their standard judges the magnitude of our globe, it appears very small. And so I think it must seem to the electrician, for when he considers the speed with which an electric disturbance is propagated through the earth, all his ideas of distance must completely vanish.”

“I have been working on that problem ever since. For a long time I experimented with delicately adjusted instruments, but I found them unreliable. I would send signals for a few blocks and then a strong current of electricity somewhere in the neighborhood or some atmospheric condition would interrupt them.

“After a time I saw that this would not do. I must have something reliable. Then I set about making a machine, which would give me more powerful vibrations. I have succeeded beyond my expectations. I have made a machine which is a thousand times as powerful as any now known. With it I could stop every electric current - every telegraph or telephone in this neighborhood.” With a sweep of his arm the inventor suggested that populous district which surrounds the building in Houston Street, where his laboratory is.

“But could not some one else destroy the effectiveness of your signals with a counter-current?” I asked.

Mr. Tesla hesitated and answered rather slowly: “Yes, yes, he could. But he’d have to be a devil of a fellow.” Which ingenious statement I interpreted as meaning that the “other fellow” would have as strong a machine as that of Mr. Tesla.

Mr. Tesla told me that the new machine filled very little space. “It is not so large as that table,” he said, indicating a very small one which stood against the wall, covered with scientific magazines.

“It could be put aboard a ship without inconvenience, then?”

“Certainly.”

“And how about the current to operate it?”

“It could be had from a small dynamo such as they have aboard all the ships in the navy.”

Mr. Tesla says that his original theory concerning the transmission of signals, and possibly of power without wires had been confirmed by his experiments. On this subject he said some years ago:

“A point of great importance would be first to know what is the capacity of the earth, and what charge does it contain if electrified? Though we have no positive evidence of a charged body existing in space without other oppositely electrified bodies being ear, there is a fair possibility that the earth such a body, for by whatever process it was separated from other bodies - and this is the accepted view of the origin, it must have retained a charge, as occurs in all processes of mechanical separation. If it be a charged body insulated in space its capacity should be extremely small, less than one-thousandth of a farad. But the upper strata of the air are conducting, and so, perhaps, is the medium in free space beyond the atmosphere, and these may retain an opposite charge.

“Then the capacity might be incomparably greater. In any case it is of the greatest importance to get an idea of what quantity of electricity the earth contains. It is difficult to say whether we shall ever acquire the necessary knowledge, but there is hope that we may, and that is by means of electrical resonance. If ever we can ascertain at what period the earth’s charge when disturbed oscillates with respect to an oppositely electrified system or known circuit, we shall know a fact possibly of the greatest importance to the welfare of the human race. I propose to seek for the period by means of an electrical oscillator, or a source of alternating electric currents.

“One of the terminals of the source would be connected to earth, as, for instance, to the city water mains, the other to an insulated body of large surface. It is possible that the outer conducting air strata, or free space, contain an opposite charge and that, together with the earth, they form a condenser of very large capacity. In such case the period of vibration may be very low and an alternating dynamo machine might serve for the purpose of the experiment. I would then transform the current to a potential as high as it would be found possible, and connect the ends of the high tension secondary to the ground and to the insulated body. By varying the frequency of the currents and carefully observing the potential of the insulated body and watching for the disturbance at various neighboring points of the earth’s surface, resonance might be detected.

“Should, as the majority of scientific men in all probability believe, the period be extremely small, then a dynamo machine would not do and a proper electrical oscillator would have to be produced, and perhaps it might not be possible to obtain such rapid vibrations. But whether this, be possible or not, and whether the earth contains a charge or not, and whatever may be its period of vibration, it certainly is possible - for of this we have daily evidence to produce some electrical disturbance sufficiently powerful to be perceptible by suitable instruments at any point of the earth’s surface.”

At the time he made this statement, Mr. Tesla proposed the following plan for signalling without wires:

Assume that a source of alternating currents be connected with one of its terminals to earth (conveniently to the water mains) and with the other to a body of large surface, P. When the electric oscillation is set up there will be a movement of electricity in and out of P, and alternating currents will pass through the earth, converging to or diverging from the point C, where the ground connection is made. In this manner neighboring points on the earth’s surface within a certain radius will be disturbed. But the disturbance will diminish with the distance, and the distance at which the effect will still be perceptible will depend on the quantity of electricity set in motion.

Since the body P is insulated in order to displace a considerable quantity, the potential of the source must be excessive, since there would be limitations as to the surface of P. The conditions might be adjusted so that the generator or source S will set up the same electrical movement as though its circuit were closed. Thus it is certainly practicable to impress an electric vibration at least of a certain low period upon the earth by means of proper machinery. At what distance such a vibration might be made perceptible can only be conjectured.

At another place Mr. Tesla said that if it was at all possible to transmit signals through the earth or its environing medium, “distance does not mean anything.” In fact, he not only suggested the wireless telegraph first, but he first suggested the means by which all after results have been achieved, and the fact that they could be made to cover great distances. The most that is claimed for Marconi by scientists is that he has succeeded in telegraphing without wires for a greater distance than any one before him. But if Mr. Tesla’s new machine accomplishes what he confidently predicts, Marconi’s laurels will be plucked very quickly from his brow.

What makes the new machine more important is its superiority to the influence of others. A recent writer on Marconi’s system said that “in war telegraphy would become impossible as soon as a hostile spark generator should cause a permanent disturbance of the characters.” If Mr. Tesla is not mistaken only “a devil of a fellow” will be able to disturb his signals; and if the Tesla system can be kept a secret there is no likelihood that any disturbing element will enter into the transmission of signals by our army and navy during the trouble with Spain.