Tesla and the Roentgen Rays

The Famous Electrician Has Succeeded in Making a Photograph of the Human Brain.

HIS FORMER INVENTION.

He Once Took Fairly Successful Cathode Pictures of Mark Twain, Joe Jefferson and Others.

HIS APPEARANCE DESCRIBED.

Mr. Tesla took a photograph of the human brain last week. I surprised the fact out of him in a conversation in which he was telling me for my own information something about the X ray, or "Roentgen ray" as it is known popularly. The photograph was not satisfactory, except as an evidence that it was possible to photograph through the skull: It remains to be seen whether the nature of the X ray limits its field to such demonstrations as have been made in the past, or whether, as Nikola Tesla says, you can take photographs through a brick wall twelve feet thick. The whole situation is summed up in his statement that if the Roentgen ray is etheric, as Roentgen believes it to be, its scope is limited to the penetration of comparatively thin substances. You can photograph through a book with it, but you cannot photograph through an inch of glass. But if the waves which produce the effects in what is called "cathode photography" are produced by waves propagated in straight lines like sound waves, their possibilities are almost boundless. Mr. Tesla has been at work in his shop on Houston street ever since the Roentgen experiments were made public, and he hopes to be able to determine in the near future the character of the agents which are at work in the Roentgen and other experiments.

TESLA'S DISCOVERY.

It is a remarkable fact that not to Roentgen nor to any of the recent experimenters is the credit of discovering the penetrative power of the X ray due. Its development, like that of most great discoveries, has been gradual and has proceeded by a regular process of evolution, in which many men of science have taken part. Mr. Tesla himself made public several years ago the fact that when there were sudden discharges of electricity through a wire, certain waves, which he designated "sound waves of electrified air," were propagated; or, as he himself explained it, "certain kinds of waves which I called 'sound waves of electrified air' are propagated from conductors when a strong rapidly vibrating current passes through them, such as sudden discharges from condensers. These propagate in straight lines like sound. They are longitudinal waves, penetrating bodies, and they cannot be stopped by interposing metal plates."

Whether his "sound waves of electrified air" are similar to the cathode ray or different from it Mr. Tesla does not yet know. But the real discovery of the Roentgen ray dates back even beyond Mr. Tesla's experiments and the use of the ray for photographing is not new. Lenard more than two years ago took photographs through metal plates and published results of experiments in the scientific papers. These experiments, like those of Mr. Tesla, were not of a popular character, and they attracted no attention outside scientific circles. It remained for Professor Roentgen to photograph money in a purse and to take pictures of the bones of the human hand. That appealed immediately to the popular imagination. When excitement has calmed down a little and the situation is reviewed credit will be given to all those who contributed to the development of the wonderful X ray and its application. Then another fact will be remembered and accorded to the credit of Mr. Tesla — that all the discoveries made through the popularization of the Roentgen experiments were made possible by a remarkable invention of Mr. Tesla — his converter. For, whether credit is given to Mr. Tesla in the reports of experiments or whether he is ignored or slighted by the mention of "a converter" used in the process, the Tesla converter is used universally to obtain the sudden discharges of electricity through which the X ray is produced.

Five or six years ago Mr. Tesla started out to find a way to produce an alternating current of high frequency of conversion from any kind of electricity. He found that he could discharge a condenser charged from a static machine (such as Roentgen is using in his experiments) or from any other source into a wire coil and get oscillations at a terrific rate. To get the secondary current which he wanted he put a second coil around the first. But the necessity of using miles of fine wire in the secondary coil made it expensive and limited its practical use. Then Mr. Tesla found a way to produce the same result with a few thick wires that was produced with a great many miles of thin wires. How he achieved this result is for scientists to know and understand. It is enough for the average intelligence to comprehend the fact that he produced a revolution in the electric world.

"If every one who uses my machine in electro-therapy alone would give me a quarter I would be a very wealthy man," he said with an ingenuous smile when I asked him what return beyond the fame of his achievement he had received. "It is used now by millions of persons, but I have never received a dollar from it, and there is no way in which I could."

I asked if there was any invention from which Mr. Tesla received an income — for ideas, however valuable, will not conduct costly experiments.

"I receive a small income from my invention of the rotating field," said Mr. Tesla, "and I have a small income from my home. And all of that I blow in here.'

THE INVENTOR'S WORK.

It was said with an accent which robbed the words of the character of slang. The gesture which accompanied them took in comprehensively the dark spaces beyond the trim little office on the second floor of the Houston street building, which has been the headquarters of the inventor since he was burned out, a year ago. Here he has been conducting experiments with which he hopes to revolutionize the production of electric power. He believes he will be able to produce electricity before long at an infinitely smaller cost than at present is possible, and with an apparatus which will be comparatively simple and cheap. But the details of his experiments in this direction are known only to himself. He took me into his workshop one day recently, but his description of it was so brief and his whole manner so indicative of horror at the thought of publicity that we were not in the room more than a minute, and the amount of information I obtained about it could be summed up in one of the shortest paragraphs ever written.

Mr. Tesla is tall and slender, with very black, thick hair. He wears a very small mustache over a small mouth. All of his features are delicate. His cheeks are rather hollow but they have the flush of health. His cheek bones are conspicuous. His manner is cordial, and as attractive in its way as his appearance for he is not the careless, begrimed machinist as he issues from his shop, but a "well groomed" man, whose clothing is stylish and well fitting, and whose hands and face are as pink and clean as a baby's. Like most inventors, he is a late worker. The forces of both mind and body, he thinks, operate better at night than in the daytime. So he is often in his shop until two or three o'clock in the morning. He seldom comes down before noon. Occasionally he is attracted by "society" and he was one of the star features at a recent "function," at which Sarah Bernhardt also shone. But his work absorbs most of his time, and he has little taste for anything else.

HIS EARLY PICTURES.

A curious fact about Mr. Tesla, which is recalled by the recent experiments with the cathode rays, is the fact that he demonstrated first the possibility of taking photographs with those rays. He took photographs of Joe Jefferson, Mark Twain and others by their light, and these photographs were reproduced to illustrate a story about his workshop. But the experiments made then did not possess the quality of popularity as did the Roentgen experiments, or, in fact, the earlier experiments of Mr. Tesla himself. Probably the only parallel to the interest displayed by the public in the Roentgen experiments is to be found in the excitement which prevailed when it was announced that Mr. Tesla had produced an illuminating glow in the centre of a room without the use of wires or other electrical connections. The popular mind conjured up at once the picture of great halls illuminated by an artificial light diffused like the daylight, and the changes were rung for many days on the possibilities to be developed under the new discovery. All of the speculation about the practical application of the discovery ceased when the workshop of Mr. Tesla was destroyed by fire, and in its destruction was lost the apparatus which it may take the greater part of a lifetime to reproduce. But during the excitement which prevailed it was said the story of the demonstrations made by Mr. Tesla in London reached the eyes of the reading public through the medium of 30,000 American newspapers.