But Edward R. Hewitt, an inventor doing photographic research at this time, has left an intriguing anecdote. His own researches “began on the morning when Nikola Tesla took a picture of Mark Twain under a Geissler tube which proved to be no picture of Twain but a good one of the adjusting screw of the camera lens.”
“Neither Tesla nor Hewitt,” wrote Noel F. Busch in Life magazine (July 15, 1946), “realized until a few weeks later, when Roentgen announced the discovery of X rays, that the picture of Twain was in fact an example of X-ray photography, the first ever made in the U.S.” This is, of course, hardly proof of priority of invention, which includes much more than achieving accidental effects, but it does suggest how far advanced Tesla’s research was at this time.
Whereas Edison hastened to try to profit from Roentgen’s discovery and Pupin was quick to try to share in its glory, Tesla’s less self-interested response was to begin an exhaustive series of experiments in X-ray phenomena and technique, the results of which he published, beginning in March 1896, in a series of articles in the Electrical Review.8
While his competitors were using Roentgen tubes for the production of weak shadows of hands and feet, Tesla claimed to be making forty-minute photographs through the human skull at forty feet. If this were true, he would have to have been using equipment far more advanced than anything we now believe existed at that time.
On April 6, 1896, Professor Pupin reported to the New York Academy of Sciences: “Every substance when subjected to the action of the X rays becomes a radiator of these rays,” and thus claimed to have discovered secondary radiation. But Tesla had already publicly reported in the Electrical Review (March 18, 1896): “I have lately obtained shadows by reflected rays only,” and described how he had excluded direct rays to obtain this effect. In testing various kinds of metals, he discovered that the most electropositive made the best “reflectors” of Roentgen rays.
Many competitors had now entered the field, including such well-known inventors as A. E. Kennelly and Edwin J. Houston, who used a simple form of Tesla coil to produce Roentgen rays. The practical Edison, delighted by the public’s enthusiasm, made a number of fluoro-scopes in the form of boxes with peepholes and placed them on display at the Electrical Exposition of 1896 at the Grand Central Palace in New York. This was the first opportunity Americans had to see their skeletal shadows, and they clamored for a place in line. Many were disappointed at not being allowed to view their brains in action. A gambler wrote to Edison asking for an X-ray device with which he could play against the faro bank.9
Prudes worried about the danger of unscrupulous manufacturers making X-ray binoculars, enabling voyeurs to strip them naked as they strolled in Sunday finery along Fifth Avenue. Well into the 1940s the foot X-ray machine in shoe stores would provide a consumer come-on for small-town America.
On the theory that blindness might be cured with X rays, numerous “treatments” were given by doctors. To the contrary, as is now known, radiation can cause “flashes” in the eye and, with overexposure, cataracts. Tesla pointed out that no evidence whatever existed for the blindness “cure” and discouraged the building up of false hopes as cruel. Edison too deplored this yet as a recent biographer notes, “he jumped in and conducted the tests along with other scientific men and doctors.”10
Tesla’s research, which was fundamental and well-documented, convinced him that X rays were composed of discrete particles. This proved to be incorrect; but so were almost everyone else’s theories in this early period. Dr. Lauriston S. Taylor, a radiological physics consultant and recent past president of the NCRP, says, “Nevertheless his reasoning was good and much to his credit.”
Almost simultaneously, at Cambridge University in England, the physicist Joseph J. Thomson had built a vacuum tube with two charged plates and a fluorescent screen. He discovered that the radiation caused by the flow of currents made dots on the screen. Both magnetic and electric fields deflected the rays of electricity, which convinced him that they were charged particles. Since the ratio of the charge on the particles to their mass was always the same, he hypothesized that he had discovered “matter in a new state” from which all the chemical elements were built up. Some years later Thomson was credited with having discovered (in 1897) the electron—a very light particle associated with the elementary charge of negative electricity and the fundamental building block of the atom.
Max Planck in 1900 proposed a law for electromagnetic radiation— the quantum theory. And five years later Einstein explained, with his special theory of relativity, that all radiation, though it consisted of quanta of different amounts of energy, traveled at the speed of light. His fundamental equations described the exchange of energy that took place when radiation and matter interacted.
From this new realm of physics came knowledge of the properties of different kinds of electromagnetic radiations. Radio waves, at the lowest frequency, stretched for thousands of miles. In the order of rising frequencies came microwaves, infrared radiation, visible light, ultraviolet radiation, X rays, and gamma rays—the latter incredibly short.
Tesla and other early experimenters with X rays were exploring treacherous territory. It was clear that radiation would be useful in detecting foreign objects in the body or bone fractures, but its full medical potential and the effect of such rays on human health entailed dangerous trial-and-error research.
“Yet in spite of some grievous accidents with X rays for their first twenty-five years,” says Dr. Taylor, “there were surprisingly few who suffered from overexposure—certainly not everyone.”11
Tesla, entranced with the novel and mysterious force, was one of those who at first refused to believe there was danger. Convinced he had discovered a way of “stimulating” his brain, he exposed his head repeatedly to radiation.
“An outline of the skull is easily obtained with an exposure of 20 to 40 minutes,” he wrote. “In one instance an exposure of 40 minutes gave clearly not only the outline, but the cavity of the eye . . . the lower jaw and connections to the upper one, the vertebral column and connections to the skull, the flesh and even the hair.”12
He noted strange effects: “… a tendency to sleep and the time seems to pass away quickly. There is a general soothing effect and I have felt a sensation of warmth in the upper part of the head. An assistant independently confirmed the tendency to sleep and a quick lapse of time.”
From such effects he was more than ever inclined to believe that the radiation was of material streams penetrating the cranium. And he was first to suggest that X rays would be used therapeutically—perhaps to “project chemicals into the human body.”13
It is difficult to gauge at this date the degree of exposure to which he subjected himself. And indeed, insofar as the brain is concerned, it is still not known what its physiological tolerances are to high-energy radio-frequency fields.
Edison damaged his eyes with X-ray exposure. One of his assistants contracted a gradually spreading skin cancer from which he died several years later.
Tesla described carefully the effects of X rays upon his own eyes, body, hands, and brain, differentiating between skin burns and what he considered to be internal effects. In the spring of 1897 he was mysteriously ill for several weeks. He reported receiving frequent sudden and painful shocks in the eye from X-ray equipment. His hands were repeatedly exposed.
“In a severe case,” he wrote, “the skin gets deeply colored and blackened in places, and ugly, ill-foreboding blisters form; thick layers come off, exposing the raw flesh. . . . Burning pain, feverishness and such symptoms are of course but natural accompaniments. One single injury of this kind in the abdominal region to a dear and zealous assistant—the only accident that ever happened to anyone but myself in all my laboratory experience—I had the misfortune to witness.”14
This had followed an exposure of five minutes, only a few inches from a highly charged tube. But apart from skin damage, he noted that such radiation caused a feeling of warmth deep in the flesh, a
fact that was to inspire his continuing work in therapeutics.
It is now known that X rays may be of two kinds—“hard” or “soft,” meaning that the latter have longer wavelengths and lower energies. They are more easily absorbed than hard X rays. Even so they are of high energy compared to ultraviolet or visible light rays.
Tesla’s research very quickly convinced him that safety measures were needed. He lectured to the New York Academy of Science on April 6, 1897, on the practical construction and safe operation of X-ray equipment as well as reporting his observations of the dangers of Roentgen rays. He had already experimented with various metal protective devices, and soon thereafter lead shields came into general use.
An important figure entered the inventor’s life at this juncture. In preparing for his Academy of Science lecture he was supplied with lantern slides and cathode tubes by an eager new assistant named George Scherff.
At first his secretary, Scherff was to become a financial and legal adviser, bookkeeper, office manager, stockholder, factotum, friend, and during acute financial squeezes, a nearly-always-reliable source of small loans. Devoted through good times and lean, he was to become Tesla’s most loyal and least dispensable employee.
Scherff never complained about long hours, scanty rewards, or the occasional thoughtlessness of his boss. If it meant depriving his own family to help Tesla out of a tight spot, the good and frugal Scherff would manage. He never questioned the fact that he was always Mr. Scherff, the loyal functionary, never an intimate or social equal. He truly worshipped Tesla, learned more about his affairs than anyone else, and would go to his grave with sealed lips where the inventor’s private matters were concerned. If ever there was a faithful friend standing behind a great man, it was George Scherff behind Nikola Tesla.
Many people continued to worry about why no good woman could be seen standing behind the celebrated inventor. Important people were expected to procreate for the good of the country. Urging Tesla to get married in 1896 were not just gossip columnists. Technical journals like the Electrical Review of London, the American Electrician, and the Electrical Journal also took up the hue and cry.
Tesla’s expertise in handling such queries is apparent at the end of a long interview he gave to a reporter for the New York Herald, who came upon him one night slumped in a café at a late hour, looking haggard and tired. He was still brooding at times over the setbacks he had suffered when his laboratory burned, but it was apparent to the reporter from his pallor and the look in his eyes that something was seriously troubling him.
“I am afraid,” began Tesla, “that you won’t find me a pleasant companion tonight. The fact is, I was almost killed today.”15
He had gotten a shock of about 3.5 million volts from one of his machines.
“The spark jumped three feet through the air,” he said, “and struck me here on the right shoulder. I tell you it made me feel dizzy. If my assistant had not turned off the current instantly it might have been the end of me. As it was, I have to show for it a queer mark on my right breast where the current struck in and a burned heel in one of my socks where it left my body. Of course the volume of current was exceedingly small, otherwise it must have been fatal.”16
It is possible that he was even minimizing the accident because of Edison’s long campaign against “deadly AC.”
The reporter asked how far sparks could travel.
“I have frequently had sparks from my high-tension machines jump the width or length of my laboratory, say thirty to forty feet,” he said. “Indeed, there is no limit to their lengths, although you can’t see them except for the first yard or so, the flash is so quick…. Yes, I am quite sure I could make a spark a mile long, and I don’t know that it would cost so much either.”
Asked whether he had suffered many accidents while working with electricity, he said, “Very few. I don’t suppose I average more than one a year, and no one has ever been killed by one of my machines. I always build my machines so that whatever happens it cannot kill anyone. The burning of my laboratory two years ago was the most serious accident I ever had. No one knows what I lost by that.”
For a moment he sat reflecting. Then, speaking in the third person, he began to explain the main source of sadness in a prolific inventor’s life.
“So many ideas go chasing through his brain that he can only seize a few of them as they fly, and of these he can only find the time and strength to bring a few to perfection. And it happens many times that another inventor who has conceived the same ideas anticipates him in carrying one out of them. Ah, I tell you, that makes a fellow’s heart ache.”
When the laboratory burned, he said, there was destroyed with it the apparatus he had devised for liquefying air by a new method. “I was on the eve of success, and in the months of delay that ensued, a German scientist solved the problem….”
It was Linde who anticipated him in this important commercial breakthrough of liquid oxygen. Tesla had been seeking a means of refrigeration for the artificial insulation of electrical mains.
“I was so blue and discouraged in those days,” he said, “that I don’t believe I could have borne up but for the regular electric treatment which I administered to myself. You see, electricity puts into the tired body just what it most needs—life force, nerve force. It’s a great doctor, I can tell you, perhaps the greatest of all doctors.”
Asked if he were often depressed, he said, “Perhaps not often. . . . Every man of artistic temperament has relapsed from the great enthusiasms that buoy him up and sweep him forward. In the main my life is very happy, happier than any life I can conceive of.”
He described the overmastering excitement of his research. “I do not think there is any thrill that can go through the human heart like that felt by the inventor as he sees some creation of the brain unfolding to success. . . . Such emotions make a man forget food, sleep, friends, love, everything.”
It was as if he had purposely led the reporter to the next question. Did he believe in marriage “for persons of artistic temperament”?
Tesla considered carefully.
“For an artist, yes; for a musician, yes; for a writer, yes; but for an inventor, no. The first three must gain inspiration from a woman’s influence and be led by their love to finer achievement, but an inventor has so intense a nature with so much in it of wild, passionate quality, that in giving himself to a woman he might love, he would give everything, and so take everything from his chosen field. I do not think you can name many great inventions that have been made by married men.”
Whether this struck the interviewer as a sly put-down of Edison, with his two marriages, he did not indicate.
Tesla hesitated and then, adverting to his single estate, added with what the reporter described as pathos, “It’s a pity too, for sometimes we feel so lonely.”
11. TO MARS
Letters from Katharine betrayed both the mercurial state of her emotions and the steady state of her interest in Tesla. At this remove of time, it is difficult to know what to make of these curious missives. Effusive and intimate, they sometimes seem to stop just short of becoming love letters, but if Katharine was tending in that direction, Tesla gave her little encouragement.
On April 3, 1896, she invited him to their home, commenting that although he had looked ill when she had last seen him, yet he had managed to cheer her up, and “now I need to be brought up again.” She mentioned that it was Easter. “I have always wondered when the great changes are in progress if you know of them,” she wrote. “Do you know when Spring is near? It used to make me so happy and now it brings me only sorrow. It means so much that I would fain escape . . . disintegration, separation. I wish that I, like you, could go on forever and forever in the same routine, without break, living my own life, as you say you do. I do not know whose life I live, it has not seemed my own. You must come tomorrow evening, you see.”1
The Johnsons spent a part of that summer in Maine, but separation from the inventor only increase
d Katharine’s sadness and her concern for his health.
“You are making a mistake, my dear friend, almost a fatal one,” she wrote. “You think you do not need change and rest. You are so tired you do not know what you need….”2
In reply to these warm letters, Tesla alternately teased her or sent flowers when he thought of it. Perhaps he sensed he might be on treacherous ground. Robert was also his friend, and Robert loved Katharine, and. . . . But at least he probably did not have to worry about his own feelings. He had scarcely ever known a moment of vulnerability.
With Johnson he exchanged notes on religion, poetry, and whether or not he should pose for a certain painter of fashionable portraits for the May number of Century. A casual effusiveness had entered their correspondence, a “Dear Luka” from Tesla to Johnson saying, “I am glad to know that you still love me….”3
Although he was no orthodox believer, Tesla commended religion as an excellent thing for others. In this period when anxiety over his inventions was stretched almost beyond bearing, and his pocketbook was equally thin, he became interested in Buddhism. It and Christianity, he believed, were to be the most important religions of the future. He therefore sent a book on Buddhism to Johnson, who replied: “Sir Knight: I did not know you were enlisted on that side of the campaign, but now when I read it I shall think of you even more frequently than usual— which is by no means seldom, let me assure you.”4
Days later when the Johnsons again invited him to dinner, he joked about his weakness for elegant people: “If you have visitors (ordinary mortals) I will not come. If you have Paderewski, Roentgen, or Mrs. Anthony—I will come. Please answer.”5
Christmas of that year was not a happy occasion for Katharine, despite or perhaps because of the usual efforts at family gaiety. She felt trapped. Although her children and husband were dear to her and she usually enjoyed the social round, a vital part of her life seemed missing. Was it worth living only for the slow disintegration she felt?