Before returning to the United States I visited my sisters in Banat. One of them was living in Idvor. On a Sunday in August during that visit I was dining in her garden. There was a high fence around it, and not far from it the boys and the girls of Idvor were dancing kolo on the village green and the older people were looking on. Presently somebody knocked on the garden-gate and my brother-in-law opened it. There stood a rider, holding with one hand his horse, which was covered with foam; in the other hand he held a telegram which he had brought in haste from the telegraph station in another village, about five miles away from Idvor. My native village had neither a telegraph nor a telephone line, although I, its son, aspired to connect telephonically every person in the United States to every other. The telegram in the rider’s hand was for me, sent by my attorney, telling me that, on the day before, my final papers had been delivered to the Marconi Company and that the check for the final payments was in his hands. “Good news,” I said to myself, and gave the rider a tip of ten florins to reward him for his haste, evidenced by the white foam on his horse. The bagpiper and the kolo-dancers stopped when they saw a ten-florin note in the rider’s hand and heard him brag that he had delivered to me a telegram from America. The wondering crowd assembled at the garden-gate, and the older peasants who had gone to school with me in my boyhood days asked me if the telegram really had come from America. When I said yes, and that it had been sent on that very morning they looked at each other and winked, as if signalling to each other to be on guard lest I fool them with an American yarn. Then the oldest one among them addressed me as follows: “Did you not tell us that between here and America there are four empires, each bigger than Austria, and then the great ocean, which one cannot cross in less than a week even in the fastest of ships?” “I certainly did say that, and I repeat it now,” said I. He added: “How can a telegram cross all that distance in less than a day?” “It could do it in less than a minute if man’s clumsiness did not delay it. It could travel from here to Vienna in less than a second,” said I, and carefully watched his expression. The old man seemed undecided; he did not know whether to take offense at my attempt to work off a silly yarn on him, or to proceed with his cross-examination, and finally decided in favor of the latter course. “Who invented all that?” asked he impatiently. “An American did it,” said I boastfully. “These Americans must be very clever people,” said he and waited eagerly for my reply. “Yes, indeed, they are very clever people,” said I. “Much more clever than anybody in this village?” was his next question, and when I assured him that the Americans were much more clever than anybody in Idvor, he fired at me the following shot: “Then how in the name of St. Michael do you manage to make a living there?”

This incident in my native Idvor did me a lot of good. The experts in Berlin and the high officers in Vienna had been most polite and complimentary, and all their well-meant adulation coming on the top of the newspaper legends about my inventions might have turned my head and made me imagine that I was a “wizard.” Many an inventor and scientist has been ruined by being persuaded that he is a “wizard.” I have always believed that when a successful inventor is exposed to dangers of that kind he should, somewhat like that king of antiquity, hire somebody to whisper as often as possible into his ear: “You are an ordinary mortal.” Whenever I see now the Elliot Cresson Gold Medal of the Franklin Institute, the gold medal of the National Institute of Social Sciences, the Edison Medal of the American Institute of Electrical Engineers, the Hebert prize of the French Academy, and several other evidences of recognition in my possession, I always think of that professor who blamed his hard luck for his failure to infer from the loaded strings which hung daily over his head what I had inferred from La Grange’s imaginary string. It was, I know, a lucky day when on the 14th of July, 1884, I found that second-hand bookshop in the Quartier Latin in Paris and picked up there a copy of La Grange’s treatise. Without it, I might have remained as ignorant of the remarkable properties of a loaded string as that professor was. My answer to the peasant’s question, “How in the name of St. Michael do you manage to make a living there?” is this: “The humble herdsman of Idvor and the famous La Grange of Paris told me how to do it.”

XII
THE NATIONAL RESEARCH COUNCIL

The mathematical problems in the theory of electrical transmission, and the research of the behavior of materials employed in the construction of inductance-coils kept me busy, and made me forget that I was missing the splendid opportunities offered by New Physics, which I always represented symbolically by the picture of a vacuum-tube, because its origin dates from Roentgen’s discovery. My complete recovery from the shock of 1896 did not reconcile me to the vacuum-tube, until several years had wiped out the memory which my mind had associated with it. By that time I had dropped too far behind the men who were leading in the procession of the revelations which New Physics had disclosed to man.

No sooner had Perrin, a French physicist, demonstrated that the cathode rays were negative electricity moving from the negative electrode of a vacuum-tube to the positive electrode than Professor John Joseph Thomson, of the University of Cambridge, proved that this negative electricity is concentrated in small corpuscles, called electrons to-day, which move with great velocities, and that the ratio of the electrical charge to the mass of each electron is experimentally determinable, and is, under ordinary conditions, a definite and invariable quantity. This learned man, when a youth of only twenty-five, had predicted in 1881, fourteen years before Roentgen’s discovery, that the cathode rays were small negatively charged bodies, moving with great velocities. Assuming them to be spherical, he calculated, by the Faraday-Maxwell electromagnetic theory, the ratio of their charge to their mass. He showed theoretically that their mass consisted of two parts, one of which is the ordinary gravitational or material mass, and the other a new mass which is proportional to the electrical energy in the electron, and that this mass also depended upon the velocity of the motion in a definite way. He devised and employed an experimental method to determine this ratio. The most remarkable feature of this interrelation between the electromagnetic mass and the velocity of motion was the fact that when the velocity approached the velocity of light the mass approached an infinitely large value. But no such extremes of velocity of motion of the electrons in a vacuum-tube were found at that time.

Becquerel, the French physicist, discovered, soon after Roentgen’s discovery, that certain substances associated with the element uranium emitted electrons, both negative and positive, without being in a vacuum-tube and submitted to the action of a great electrical force. Madame Curie isolated the most active of these substances and called it radium. The action of electron emission discovered by Becquerel was called radioactivity. Three distinct things, it was found, were emitted by radium: negative electrons, the so-called beta rays, some of which were moving with enormous velocities; positive electrons, the so-called alpha rays, moving with smaller velocities; and, finally, an emission which had the same physical properties as the X-rays. The beta rays, some of which move with a velocity nearly equal to the velocity of light, enabled the physicists to determine experimentally, employing J. J. Thomson’s method, the relation between the mass of the electron and its velocity, and lo and behold, it was found that, in all probability, the negative electron contained no other mass except the mass due to its electromagnetic energy. In other words, a negative electron is concentrated electricity and nothing else. Similar experiments with positive electrons led to similar conclusions. Another most remarkable result was the revelation of the great difference between the masses, and, therefore, between the electrical energies residing in the negative and in the positive electron. The mass of a positive electron was found to be very nearly equal to the mass of a hydrogen atom, and the mass of a negative electron was found to be only about one two-thousandth part of the mass of the positive electron, and this meant that if the electrons are of spherical shape then the diameter of the positive electron is only one two-thousandth part of the diameter of the negative electron, since the energies and therefore the masses are inversely proportional to the diameters. In other words, there is in the positive electron a much bigger concentration of electricity than in the negative and, therefore, much more work was used up to produce that concentration. Experimental data and calculation gave for the diameter of a negative electron one ten-thousandth part of the diameter of the smallest atom, that is, of the hydrogen atom, and therefore the diameter of the positive electron should be only one twenty-millionth part of the diameter of a hydrogen atom. A most bewildering revelation!

The remarkable results of these historic experiments forced, one may say, upon the physicist the electromagnetic theory of matter, the theory, namely, that the ultimate components in the structure of matter are positive and negative electrons. This theory was vaguely foreshadowed by Faraday in his poetic visions suggested by his researches on electrolysis. Needless to say, the physicists in the United States were thrilled by these revelations, and by the new views disclosed by them, perhaps even more than by the discoveries of the X-rays and of radioactivity. The first visible effect of this thrill was the organization in 1899 of the American Physical Society, a quarter of a century after Tyndall’s visit to this country. Just think of it, the great United States had no physical society prior to that time!

It is an interesting fact that two of the most important American organizations in abstract science were started at Columbia College. The first was the American Mathematical Society. In 1888, two young instructors at Columbia College, Fiske and Jacoby, started a mathematical club. To-day the first is a professor of mathematics, and the second is a professor of astronomy at Columbia University. I joined them in 1889, as soon as I had returned to Columbia. We transformed the mathematical club into the New York Mathematical Society, and elected for president the famous Columbia don, the late Howard Van Amringe, for many years senior professor of mathematics at Columbia College. Doctor Fiske was its secretary; no young and struggling scientific organization ever had a better secretary. The society prospered, and in 1894 it was transformed into the American Mathematical Society, counting among its members most of the distinguished mathematicians of the land. I am certainly very proud that I am one of its charter members.

In 1899 several Columbia physicists, including myself, and their friends from Johns Hopkins, Harvard, Yale, Princeton, Cornell, Clark, and other places, met at Columbia and organized the American Physical Society. The late Professor Rowland, of Johns Hopkins, was elected its president, and one of its most distinguished members was Professor Ernest Rutherford, of McGill University, Montreal. He is now Sir Ernest Rutherford, the Cavendish professor of physics at the University of Cambridge, occupying the professorial chair once occupied by Maxwell, then by Rayleigh, and then by Thomson, now Sir John Joseph Thomson, master of Trinity College, Cambridge. Their names I have mentioned often in the course of this narrative. It was most unfortunate for the progress of American physics that because of his failing health Rowland’s wonderful influence in the society was of short duration. He died in April, 1901, while still a young man. Rutherford’s wonderful discoveries in radioactivity were reported regularly by himself at the meetings of the society, and I often thought that these reports alone, even without the many other good things which came along, amply justified the existence of the society. When I compare the American Physical Society of twenty years ago with the American Physical Society of to-day I can scarcely believe that so much progress has been possible in so short a time. I recognize, however, that this remarkable growth is clue not only to the energy of youth of this country but also to the energy of youth of New Physics, which I call Electron Physics.