did. The fundamental idea underlying his beautiful research and its

relation to the Faraday-Maxwell far-reaching electromagnetic theory can be described in very simple terms. The wonderful achievements of radio broadcasting alone, to say nothing of other much more important achievements, demand this description. That idea, like the tiny seed hidden in a beautiful flower, lay hidden in Faraday’s visions and in Maxwell’s wonderful, but, to most ordinary mortals, enigmatic interpretation of them. Hertz, guided by his great teacher, Helmholtz, caught the hidden seed and out of it grew a physical embodiment of the Faraday-Maxwell theory, represented by ideally simple apparatus, operating in an ideally simple way. The apparatus and its operation are now the heart and soul of a new art, the radio art, a beautiful daughter of the beautiful mother, the Faraday-Maxwell electromagnetic science. The following description of Hertz’s apparatus and of its operation was the theme of popular lectures and of many conversations which I had with my friends who were not physicists by profession. It represents quite closely the simple picture which I carried away in my mind from that memorable meeting of the Berlin Physical Society thirty-six years ago.

Two equal metal spheres _A_ and _B_, each twelve inches in diameter, and each carrying copper rods _C_ and _D_, are placed as indicated in the diagram given here. At _E_ is an opening of about three-tenths of an inch in length, the so-called _air-gap_. By means of two wires _e_ and _f_, connected to an electrical machine, the spheres are charged, one receiving a positive electrical charge denoted by the (+) sign, and the other a negative one, denoted by the (-) sign. The air-gap _E_ insulates one sphere from the other, and its function is to make it possible for the electrical machine to increase the two charges until a very high electrical tension is reached. When the electrical tension between the two charges, acting through the air-gap _E_, is sufficiently high, then the insulating power of the air-gap is overstrained and suddenly it breaks down and becomes conductive and permits the two charges to rush toward each other. The conductivity of the air-gap suspends the action of the charging machine. A large current passes then between the two spheres along the rods and through the air-gap _E_ which is heated by the current to white heat. It becomes then a very good conductor and permits the charges to pass through it easily. The collapse of the air-gap is reported by the sharp crack of the electrical spark which is due to the very sudden heating and expansion of the air in the air-gap produced by the passage of the electrical current. It is a miniature lightning. The two charges reunite, the spheres are discharged, and after that the air-gap _E_ recovers quickly from its breakdown and becomes an insulator again. The process is then repeated by the action of the machine and a rapid succession of sparks can be maintained, each one of them announcing by the crack of the spark the reunion of the charges that had been pulled apart and forced to the surfaces _A_ and _B_ by the action of the electrical generator.

All this was known long before Hertz. The first experiment of this kind I saw in Panchevo in my boyhood days, when my Slovenian teacher Kos explained to me the theory of lightning according to the views of Benjamin Franklin, a theory which clashed with the St. Elijah legend of Idvor and nearly proved me guilty of heresy. But there was something in these electrical discharges that Benjamin Franklin did not know, and that knowledge was first suggested by another great American scientist, a scientist even greater than Benjamin Franklin was in his day.

As far back as 1842 our own Joseph Henry performed experiments similar to those performed by Hertz, and he inferred, prophetically, that the discharge was oscillatory. Nobody ever suggested this idea before, but Henry’s experiments permitted such an inference. Its oscillatory character was then demonstrated mathematically in 1853 by Professor William Thomson of Glasgow, and his calculation was proved to be correct by many experimental tests covering a period of over twenty-five years, and thus the electrical oscillator, similar to the one employed by Hertz, became a well-known apparatus.

What, then, was the novel element in the Hertzian work? It was, broadly speaking, his demonstration that the space surrounding the oscillator (the spheres with their rods) participates in the electrical oscillations in perfect agreement with the Faraday-Maxwell theory; a participation which was foreign to all previous electrical theories. In other words, he detected in the old electrical-oscillation experiments a new action, never detected nor even dreamed of before. He discovered the electrical waves in the space outside of the oscillator. Remembering the impression which Helmholtz’s lecture on Faraday made upon my mind, I was certain at that time that nobody in Continental Europe but one of Helmholtz’s pupils like Hertz could have predicted that there was in these well-known electrical oscillations a new action, an action demanded by the Faraday-Maxwell theory. A simple analogy will, I trust, help much to illustrate the new action which Hertz expected when he started out to search for an experimental test of the modern electromagnetic theory. No scientific expedition ever started out in search of scientific treasures and returned with a richer load.

Here is the analogy:

If by the force of our fingers we deflect the ends of the prongs of a tuning-fork and then let go, the prongs will return to their normal position after performing a number of vibrations of gradually diminishing amplitude. The state of rest is reached when the energy of bending, produced by the work of our fingers, has been expended, partly in overcoming the internal friction in the tuning-fork, partly in overcoming the reactions of the surrounding medium, the air; this last effect results in sound-waves which are radiated off into space. The stiffness and the mass of the prongs of the fork determine the period of vibration, that is, the pitch of the fork.

I confess that in the course of my life since my Berlin days I afforded considerable amusement to my friends whenever I tried to explain to them the Hertzian experiments by appealing to what I considered a well-known action of the tuning-fork. Some of them objected on the ground that this action is just as difficult to understand as the action of the Hertzian oscillator. I met this objection by describing to them the action of the reed in Serbian bagpipes which I watched when I was a boy, and understood sufficiently well to recognize later in the action of the tuning-fork a performance similar to that of the reed in the Serbian bagpipes. I understood the tuning-fork because I understood the reed. An educated American, I claimed, should find no difficulty in understanding the action of a simple mechanism which an uneducated Serbian peasant boy understood.

The Hertzian electrical oscillator, described above, acts like the tuning-fork. The process of pulling apart the two charges, the positive from the negative, and of forcing them to the surface of the spheres by the action of the electrical machine, is a parallel to the process of deflecting by the pressure of our fingers the prongs of the tuning-fork from their normal position. In one case the tuning-fork by its elastic stiffness reacts against the bending of the prongs. In the electrical case the electrical lines of force in the space surrounding the oscillator react against the action of the machine which crowds them into this space by stretching and compressing them. This is the picture of the action of the lines of force which Faraday gave me on the island of Arran, but I did not understand it. In the picture the dotted curves are the Faraday lines of force and the arrow-heads indicate the direction of the electrical force. The Hertzian oscillator, and what Helmholtz had told me before, made Faraday’s language and thoughts much more intelligible. The work done by the machine is all expended upon the stretching and compressing of the lines of force into the space outside of the spheres, that is, upon the _electrification of that space_.

Compare now the motion of the tuning-fork, after the pressure of the fingers has been removed, to the electrical motion when the air-gap has broken down and the action of the electrical generator suspended. The prongs are driven back to their normal position by the elastic reaction due to the bending; but when they reach that position they are moving with a certain velocity, and their momentum carries them beyond that position; they move on until the energy of the moving mass has been expended in the work of bending the prongs in the direction opposite to that of the original bending. The prongs begin then to move back in the opposite direction, starting the second cycle of motion. The same line of reasoning will carry us into the third and fourth and every succeeding cycle of motion. It is obvious that these cycles will follow each other during equal intervals of time, which gives a definite pitch to the tuning-fork. A periodic motion of this type is called an oscillation or vibration; and it is clear that it is a periodic transformation of the energy of elastic bending into energy of motion of the mass of the prongs including the surrounding air, and vice versa. The motion is finally reduced to rest when the energy of bending, produced at the start by the work of the fingers, has been used up. The question, what has become of that energy? is very important in this connection. The answer is: It is used up partly in overcoming internal friction and _partly in overcoming the reactions of the surrounding air, which result in sound-waves_. A sound-wave is a short name describing the physical fact that in the air here are compressions and dilatations alternating at periodically recurring intervals. The production of sound-waves in the air is a proof that the air in the space surrounding the tuning-fork participates in the motions of the tuning-fork.

A perfectly analogous experiment was performed by Hertz with his electrical oscillator, and his principal object was to find whether the electrical field, that is, the electrified space surrounding the oscillator, reacted as did the air driven by the vibrating tuning-fork; if it did it would develop electrical waves. If these electrical waves actually existed, what did Hertz expect them to be? In the description of the oscillator and of its action, given above, two things only were mentioned: the action of the electrical machine which charges the oscillator and the reaction of the lines of force against the tensions and pressures which crowd them into the surrounding space. The electrical waves can, therefore, be nothing else than periodic variations of the tensions and pressures in the lines of force, that is to say, periodic variations in the destiny of the lines of force in the space surrounding the oscillator. This was what Hertz had found.

The breakdown of the air-gap in the electrical oscillator and the consequent suspension of the action of the electrical generator is analogous to the removing of the pressure of the fingers from the prongs of the tuning-fork. The electrical charges on the spheres with the lines of force attached to them, strained by tensions and compressions, are released, and they move toward each other through the conducting air-gap. Just as the prongs of the tuning-fork, after the pressure of the fingers has been removed, cannot remain in the strained position in which they have been bent, so the electrical lines of force, after the insulating air-gap has broken down and the action of the machine been suspended, cannot remain in the position to which they are stretched; they contract, and hence their positive terminals on one sphere and the negative on the other move toward each other. The motion of the strained lines of force with their terminals, the charges on the spheres, has a momentum. Maxwell was the first to show that the momentum of the moving electrical lines of force is equal to the number of magnetic lines of force which, according to Oerstedt’s discovery, are produced by the motion of the electrical lines of force.

The motion of the electrical lines of force has not only momentum but also energy. Employing Faraday’s mode of expression we can say that the electrical energy of the stretched electrical lines of force is thus transformed into energy of the electrical motions. This is perfectly analogous to the passage of the elastic energy of the bent prongs of the tuning-fork into the energy of motion of the moving mass of these prongs. Again, just as the momentum of the moving mass of the tuning-fork bends the prongs in the opposite direction and continues this bending until that motion has disappeared, so the momentum of the moving electrical lines of force will stretch again the electrical lines of force and continue this stretching until the energy of motion has disappeared, when the two spheres are charged again, but in the direction which is opposite to that in the beginning. A new cycle of electrical motion is then started again by the stretched electrical lines of force, repeating itself in an oscillatory fashion until the original electrical energy, produced by the charging electrical machine, has disappeared.

But where has the energy gone? This question is just as important in this case as it was in the case of the tuning-fork. The old electrical theories answered this question one way, and Maxwell, inspired by Faraday, answered it in another. The old theories maintained that there is no other electrical motion except the motion of the charges along the conducting surface of the spheres and the rods. They paid no attention to the motion of the lines of force, because they knew nothing about them. Their vision did not see the lines themselves but only their terminals, the charges. Hence, according to the old theories, all of the energy imparted by the machine is transformed into heat in the conducting parts of the oscillator.

Hertz was the first to prove that a part of the energy is radiated off into space, in a similar manner as the energy of a tuning-fork is radiated off in the form of sound waves. He detected in the space surrounding the oscillator the presence of electrical waves, that is, periodically recurring variations of the density of the electrical lines of force; he measured their length, and, having calculated the period of his oscillator, he divided the wave-length by the period and obtained the velocity of propagation. It came out, in his earliest experiments, roughly equal to the velocity of light, as the Faraday-Maxwell theory had predicted. The waves were reflected and refracted by insulators denser than air, and all these and other effects Hertz demonstrated to follow the laws which hold good for light, supporting admirably Maxwell’s theory that light is an electromagnetic disturbance. Even this preliminary report which Hertz had sent to Helmholtz convinced everybody that the Faraday-Maxwell electromagnetic theory had triumphed, and that our knowledge of electromagnetic phenomena had been wonderfully extended. Subsequent experiments by Hertz and others added more and more laurels to this first victory.

That meeting of the Physical Society in Berlin was what I always considered the inauguration day of the electromagnetic theory. Prior to that day the theory existed in all its beautiful completeness, but it dwelt on high in the celestial heights of Faraday and Maxwell. Continental physicists needed the guidance of a Helmholtz to reach these heights. After that day it came down to earth and lived among mortal men and became part of their mode of thought. It was a heavenly gift which Hertz brought down to earth. Everybody was convinced that the science of light had become a part of the science of electricity.

_This new knowledge was the second great revelation of the nineteenth century. The wonderful things which followed in its wake, even before the nineteenth century had closed, testify to the greatness of that revelation._

I have often asked myself the question, Why did not our Joseph Henry, who discovered the oscillatory electrical motions and operated with apparatus similar to that employed by Hertz, pursue his studies further than he did in 1842? and why did not Maxwell, the formulator of the modern electromagnetic science, perform those ideally simple experiments which Hertz performed? The knowledge of the electrical oscillator was the same in 1865 as in 1887, and Maxwell undoubtedly had that knowledge. History offers an answer to these questions and this answer throws a splendid light upon the character of these two great scientists.

Soon after 1842 Joseph Henry resigned his professorship at Princeton College, and bade good-by to his laboratory where he had made several of his splendid discoveries, and where in 1832 he had constructed and operated the first electromagnetic telegraph, one of the practical results of his great discoveries. This happened long before Morse had ever been heard of. Henry’s fame among men of science was very great and promised to grow even greater if he continued his scientific researches. He was still in his prime, only a few years over forty. But a patriotic duty called him to Washington, where the Smithsonian Institution waited for his skilled hand to organize it and to defend it against the scheming politician. This duty tore him away from his beloved laboratory, and he spent the rest of his life, over thirty years, in Washington as secretary of the Smithsonian Institution, as originator of most of the national scientific bureaus of which this country is proud to-day. He was also the first president of the National Academy of Sciences, chartered by Congress in 1863, thanks to his efforts. Physical science under his leadership had rendered valuable service to the country during the Civil War, and the congressional charter to the National Academy of Sciences was a graceful recognition of this service. I have already pointed out Joseph Henry’s splendid efforts for the advancement of scientific research in this country and shall return to it later. He was a great scientist, but he was also a great patriot; his country stood first and his own scientific achievements and fame stood second in his heart. That, I am sure, was the reason why he did not pursue any further than he did his researches of electrical oscillations. I will mention here that one of the most gratifying results of my humble efforts was the naming of an electrical unit after his name. My colleague, the late Professor Francis Bacon Crocker of Columbia University, joined me most enthusiastically in these efforts; and the Electrical Congress in Chicago in 1893, at which Helmholtz presided, adopted the name Henry as the unit of electrical inductance; the unit Farad was named in honor of Faraday. No other electrical units are in more frequent use than the Farad and the Henry, particularly in the radio art. No other men contributed to this art as much as Faraday and Henry did.

Maxwell resigned his professorship at King’s College, London, at the end of 1865, soon after he had communicated to the Royal Society his great _memoir_ on the electromagnetic theory. The electromagnetic theory of light which, as I pointed out before, he had called “great guns” in a letter addressed to a friend, was the climax of it. He retired to his country place, Glenlair, in Scotland, and for five years he was free to devote his entire time to study and meditation. That was the highest joy of his life. But the Duke of Devonshire, a loyal Cambridge man, had presented the university with a goodly sum of money for the building and equipment of a physical laboratory. It was to be named the Cavendish laboratory, after Lord Cavendish, the Duke’s illustrious ancestor, who had devoted his life to electrical science. This gift was the Duke’s response to the Cambridge movement in favor of scientific research. Maxwell was called to Cambridge to become the director of the new laboratory, and he responded, knowing well that, from that moment on, most of his time would be devoted to organization and administration. Duty to his university, and to the cause of scientific research in Great Britain, stood higher in his heart than the experimental demonstration of his great theory; that was certainly one of the reasons why Maxwell did not perform those ideally simple experiments which Hertz performed. But as director of the Cavendish laboratory he had trained a number of men, in order to prepare them to push on the line of advance where he had left it; and one of them, in particular, was soon to take the leadership in the rapid development of the Faraday-Maxwell electromagnetic theory.

The examples of Henry and of Maxwell must have been in Andrew White’s mind when in 1873 he spoke those memorable words which I quoted before and will quote here again:

I will confine myself to the value, in our political progress, of the spirit and example of some of the scientific workers of our day and generation. What is the example which reveals that spirit? It is an example of _zeal_, ... of _thoroughness_, of _bravery_, ... of _devotion to duty_ without which no scientific work can be accomplished, ... of _faith_ that truth and goodness are inseparable.

The Hertzian experiments created quite an upheaval in the research programme of the Physical Institute; everybody seemed anxious to drop his particular subject of research and try his hand at the Hertzian waves. Several candidates for the doctor’s degree yielded, but I resisted and returned to my problem in physical chemistry, and plodded along as if nothing had happened. I was very anxious to finish my research, get my doctor’s degree, and return to the United States. But I soon found out that there are currents in human life which can influence the course of life of a young scientist much more powerfully than even a new and powerful current of thought in physical sciences.

During the first two months of 1888, Nikola, the Bosnian Serb, began to look worried. He informed me confidentially that he had received bad news about the health of his great “komshiya,” the aged Kaiser. The audiences at the palace were separated by longer and longer intervals, and Habel’s long table began to look deserted; the old generals with their splendid uniforms were conspicuously absent and the historic chop-house began to look commonplace. The daily parades of the guards were finally suspended, and there were no expectant crowds in front of the Imperial palace. The gay life of Unter den Linden became very much subdued. Finally the historic event occurred: the great emperor died on March 9, 1888. Berlin went into mourning and prepared for a funeral such as Germany had never seen before. “I have secured a balcony for you and your friends right over my store,” said Nikola; “I want you and your friends to see the funeral procession as my guests.” His grief over the death of the old emperor was really pathetic. He wanted me and my American friends to see the great procession which, according to his gloomy forebodings, was to mark the first step downward in the wonderful development of the German Empire. When, consoling him, I pointed out the well-known virtues of Crown Prince Frederick, he took hold of his larynx and his gesture indicated that he expected the death of the Crown Prince from his incurable malady. “What then?” I asked him. He answered: “Ask your Bismarck and Moltke, Helmholtz and Siemens; they are your oracles, perhaps they can answer your question; no ordinary mortal can.”

Nikola had never met my American friends whom he mentioned in his invitation, but he had heard a great deal about them. My classmate at Columbia, A. V. Williams Jackson, now the distinguished Orientalist and professor at Columbia University, was at that time at the University of Halle, studying with the great Orientalist, Professor Geltner. He had visited me in Berlin and I returned his visit by spending with him a week-end at Halle. This was shortly before the great Kaiser’s death. Jackson’s mother and two sisters were there on a longer visit, and for two days I felt that I was back in New York again, and I was supremely happy. On the way back to Berlin I could not dismiss from my mind the memory of my mother’s words: “You must marry an American girl if you wish to remain an American, which I know you do.” Ever since my return from Halle, I could hear these words ringing in my ear no matter where I was, in my lodgings, in the laboratory, in the lecture-rooms, or even in Nikola’s store. Nikola had read my thoughts, and when he mentioned my American friends he meant Jackson and his mother and sisters at Halle. Well, they came, they saw, and they conquered. One of Jackson’s sisters went to Italy during that spring and I followed; she returned to Berlin to join her mother and I followed; she went to the island of Norderney, in the North Sea, to spend a part of the summer season, and I followed. The Faraday-Maxwell electromagnetic theory and the Hertzian experiments, my research in physical chemistry, and the learned essays of Helmholtz and Willard Gibbs, and of all the other fathers of physical chemistry, disappeared from my mind as if they had never been there. The only problem that could find a place there was the question: Will she accept me? She finally did, and I made a bee-line for New York, in order to find out how soon I could get a job there.

The Columbia authorities were organizing at that time a new department in the School of Mines, the Department of Electrical Engineering, and they were glad to see me and consult me about it. It was to start its work a year from that time, that is, the end of September, 1889. I was offered a position in it as “Teacher of Mathematical Physics in the Department of Electrical Engineering.” A very long title, indeed, but such it was and an interesting bit of history is attached to it. I accepted gladly and hurried back to Europe proud as a peacock. My fiancée and her family met me in London and I was married in the Greek church, according to the rites of the Orthodox faith, the faith of my mother and of all my ancestors.

“Marriage gives that fulness to life which nothing else can give,” said Helmholtz when I saw him again in Berlin and informed him that I was married and that I had been promised an academic position at Columbia College. He approved my dropping the experimental research and substituting in its place a mathematical research in physical chemistry. This research was finished in the early spring and I sent it to Helmholtz who was then in Baden-Baden. He telegraphed: “Your successful effort approved and accepted.” Never before nor since did I ever receive a telegram which made me more happy. The examinations gave me no serious trouble, and in the late spring of that year I had my doctor’s degree and became a citizen in the world of science. The three theses which, according to old German custom, every candidate seeking promotion to the dignity of a doctor of philosophy must frame and defend publicly are given here, in order to show my final mental attitude which was formulated by my scientific studies in Europe.

I. Instruction in Physics in the preparatory schools should be as much as possible a practical one.

II. The Thermodynamic methods of Gibbs, von Helmholtz, and Planck form the most reliable foundation for the study of those physical processes which we cannot analyze by ordinary dynamics.

III. The Electromagnetic Theory of Light deserves more attention than it has received so far in university lectures.

Usually these theses, appended to German doctor dissertations, are not taken very seriously either by the candidate, who is to be promoted, or by anybody else. But I took my theses very seriously. The first summed up President Barnard’s doctrine relating to scientific instruction, which I described before in connection with my description of the American movement favoring scientific research in American colleges and universities; the second summed up my admiration for the new science of physical chemistry first started by our own Josiah Willard Gibbs; and the third summed up my love for the Faraday-Maxwell electromagnetic science. On these three questions in physical science I had, I thought, quite clear and definite ideas; and that gave me much confidence that I was about to return to the United States sufficiently equipped to render service in return for some of the many favors which I had received.

As the ship which carried me back to the United States entered New York Harbor I saw on my right Castle Garden; it looked the same as it did fifteen years before, when I first entered on the immigrant ship, and it reminded me of that earlier day. I said to my bride, who was standing by my side, that I did not carry much more money into New York Harbor than I did fifteen years before, when I first looked upon Castle Garden, and yet I felt as rich as a Crœsus. I felt, I told her, that I owned the whole of the United States, because I was sure that the United States owned me; that I had an ideal American bride, who had assured me that I had lived up to the standards of an ideal American bridegroom; and that I had a fine position in a great American institution and strong hopes of filling it to everybody’s satisfaction. I enumerated all these and other things to my bride and wound up by saying, jokingly: “I have also some prospects which modesty prevents me from mentioning,” and then I added: “These are the only worldly goods with which I thee endow.”

X

THE FIRST PERIOD OF MY ACADEMIC CAREER AT COLUMBIA UNIVERSITY

The new “Department of Electrical Engineering in the School of Mines of Columbia College” had announced its courses of instruction quite a number of months before I arrived in New York. The late Francis Bacon Crocker, at that time the newly appointed instructor in electrical engineering and my future colleague and life-long friend, had been consulted with regard to these courses, and he was most liberal to the theoretical side, which was to be my share of the instruction. He attached much importance to the fundamental theory, although he was a practical engineer. The new department was to be independent of the other scientific departments. We had some difficulty, however, in maintaining that independence; the older departments of engineering showed a disposition to claim some right of guardianship over the new infant department. For instance, many chemists thought that electrical engineering was largely chemistry on account of the storage batteries, the galvanic cells, and the electrochemical processes which formed an important part of the electrical operations in the early history of applied electricity. Others asserted that, since mechanical engineering attended to the design and the construction of electromagnetic generators and to the power plant which furnished the driving power, electrical engineering was, therefore, largely mechanical engineering.

Crocker and I maintained that there is an electrical science which is the real soul of electrical engineering, and that every other abstract science or its application was an incident only in electrical engineering. We won out in spite of the fact that at other institutions of higher learning in the United States electrical engineering was taught in the departments of physics or of mechanical engineering. But it was not an easy matter in those days to persuade people that the electrical science with its applications was then, or that it ever would be, big enough to need a department of its own, like, for instance, civil engineering.

A small brick shed, a temporary structure, had been built at Columbia College to accommodate the new department. The students called it the “cowshed,” and the boy who invented the name did not indulge in any stretching of his imagination. It certainly looked like a cowshed. The laboratory equipment consisted of a dynamo, a motor, and an alternator, with some so-called practical measuring instruments. When I compared the facilities of the new “Department of Electrical Engineering at Columbia College” with that of the Polytechnic School in Berlin, I felt somewhat humbled, but not discouraged. I said to Crocker: “Our guns are small and few in number; the men behind the guns will have to expand much beyond their present size if this department is to make any impression upon the electrical art.” “Pupin,” said Crocker, “you have no idea how rapidly a young fellow grows when he tries to teach a new subject to poorly prepared beginners.”

Crocker and I were given to understand that any additional equipment during the first year would have to be bought from contributions outside of the university. We raised some money by giving a course of twelve popular lectures for which we charged ten dollars per person. Each lecture lasted two hours; we were somewhat dubious about their quality, and so we provided a generous quantity. We raised in this manner three hundred dollars and bought additional equipment, but no two young scientists ever worked harder to earn three hundred dollars. The experience, however, was worth many times that amount. Our audience consisted of business men and lawyers, who were either interested in the electrical industries, or expected to become interested. They had hardly any previous scientific training. It took much judgment and skill to talk science to these people without shooting much above their heads. Every one of them believed that the electrical science was in its infancy, and that most of its useful applications were obtained empirically by a rule of thumb. When we told them that the electrical science was one of the most exact of all physical sciences, some shook their heads and exhibited considerable scepticism. One of them asked me: “Doctor, do you know what electricity is?” “No,” said I, and he added another question: “Then how can you have an exact science of electricity when you do not even know what electricity is?” To this I retorted: “Do you know what matter is? Of course you do not, nor does anybody else know it, and yet who will deny that there are exact sciences relating to material things? Do you deny that astronomy is an exact science?” It is a difficult thing to make unscientific people understand that science studies first and foremost the _activities of things and not their ultimate nature_.

In that first course of public lectures I found it necessary to devote much of my exposition to the correction of erroneous notions lodged in the minds of my audience. When I told that audience that no electrical generator generates electricity, because electricity was made by God and, according to Faraday, its quantity in the universe is constant, and that for every positive charge there is an equal negative one, most members of my audience were inclined to think that I was talking metaphysics. “Then what does it generate?” asked one of my hearers. I answered: “It generates motion of electricity, and by that motion it furnishes us with means of doing useful work like telegraphy, telephony, and electrical lighting.” Then I added: “The electrical science studies the forces which make electricity move against the reactions of the bodies through which it moves; in the overcoming of these reactions the moving electricity does useful work.” Illustrations from dynamics of material bodies did not help very much, because my audience had hardly any knowledge of even the elements of Newton’s great work, although Newton considered these elements obvious truths. All they knew about Newton was that he had “discovered gravitation.” When I told them that Newton had discovered the law of gravitational action and not gravitation itself, they thought that I was splitting hairs. I was never quite sure that those good people had carried away much knowledge from my lectures, but I was quite sure that they had left much knowledge with me. In trying to straighten out their notions I straightened out my own very considerably. Crocker was right when he said: “You have no idea how rapidly a young fellow grows when he tries to teach a new subject to poorly prepared beginners.” That was the real profit from our first course of public lectures.

Every cultured person is expected to have an intelligent view of literature, of the fine arts, and of the social sciences, which is as it should be. But who has ever thought of suggesting that culture demands an intelligent view of the primary concepts in fundamental sciences? If cultured people had it, there would be no need to renew periodically the tiresome topic of the alleged clash between science and religion, and there would be much more straight thinking about things in general. Every child in the public schools should be made perfectly familiar with the simple experiments which illustrate the fundamental elements of Newton’s divine philosophy, as Milton calls science. Barnard, Joseph Henry, Andrew White, and the other leaders of scientific thought in the United States, who started the great movement in favor of higher scientific research and of a better scientific education, had a difficult up-hill pull, because people in high places lacked an intelligent view of science. A famous lawyer, a trustee of a great educational institution, looked surprised when I told him, over thirty years ago, that one cannot teach science without laboratories both for the elementary and for the advanced instruction. He actually believed that graduate schools in science needed only a lot of blackboards, chalk, and sponges, and a lecturer who could prepare his lectures by reading books. He believed what he thought would suit him best, namely, that a university should be built on the top of a heap of chalk, sponges, and books. These instrumentalities are cheaper than laboratories, and that appeals to many university trustees. The teacher who can lecture from books and not from his experience in the laboratory is also much cheaper. But heaven help the country which trusts its destiny to cheap men operating with cheap instrumentalities. I gave that trustee a lecture by reciting the sermon which Tyndall preached in the “Summary and Conclusions” of his famous lectures of 1872-1873. I was bold enough to deliver several of these lectures to men in high places. Some liked them and some did not, but they all agreed that I had my own opinions upon the subject and was not afraid to express them.

The American Institute of Electrical Engineers had heard of my somewhat novel opinions regarding the teaching of the electrical science in its bearing upon electrical engineering, and it invited me to give an address upon the subject at its annual meeting in Boston, in the summer of 1890. The address was entitled “Practical Aspects of the Alternating Current Theory.” It was a eulogy of the electrical science, and particularly of Faraday, Maxwell, and Joseph Henry on the purely scientific side, and of the technical men who were developing the system of electrical power distribution by alternating electrical forces. I noticed that my audience was divided into two distinct groups; one group was cordial and appreciative, but the other was as cold as ice. The famous electrical engineer and inventor, Elihu Thomson, was in the friendly group, and he looked me up after the address and congratulated me cordially. That was a great encouragement and I felt happy. Another man, a well-known physicist and engineer, also looked me up, and asked me whether I really expected that students of electrical engineering could ever be trusted to swallow and digest all the mathematical stuff which I had presented in my address. The “mathematical stuff” to which he referred was a very elementary theoretical illustration. I thought of my chums, the tripos youngsters at Cambridge, and of their wonderful capacity for swallowing and digesting “mathematical stuff,” but said nothing; the man who was addressing me was one of those people who had a small opinion of the capacity and willingness of our American boys to “swallow and digest” just as much “mathematical stuff” as their English cousins do.

A short time prior to my return to Columbia College, in 1889, a bitter polemic had been carried on in the New York newspapers concerning the two methods of electrical power distribution, the _direct_ and the _alternating_ current method. The New York interests favored the first, and another group, including the Westinghouse Company, supported the alternating current method. The opponents of the latter method called it the “deadly alternating current,” and did their best to discredit it. They actually succeeded, I was told, in persuading the State authorities to install an alternating current machine at the Sing Sing prison, to be used in electrocution. When in my address at Boston I recited my eulogy of the alternating current system I did not know of this bitter polemic, but when I heard of it I understood the chilliness among a part of my audience.

In the following autumn I was made to understand that my address in Boston had made a bad impression, and that it had offended the feelings of some _big_ men who were interested in the electrical industries. I could not help seeing the glaring hint that the new “Department of Electrical Engineering at Columbia College” was to suffer from the fact that one of its two instructors was accused of an unpardonable “electrical heresy.” The great and mighty person who broached this matter to me suggested that perhaps the easiest way out of this difficulty was my resignation. “Very well,” said I, “I will certainly resign if the trustees of Columbia College, who appointed me, find me guilty of a scientific heresy.” The trustees never heard of this incident, but my colleague Crocker did, and he said in his characteristic manner: “There are many persons to-day who would not hesitate to burn the witch of Salem, but no persons of that kind are on the board of trustees of Columbia College.” Crocker was a Cape Cod man and he had a very soft spot for the witch of Salem.

The notion among many captains of industry that the electrical science was in its infancy, and that it worked by the rule of thumb, made it possible to launch an opposition of that kind against the introduction of the alternating current system of electrical distribution of power. Tesla’s alternating current motor and Bradley’s rotary transformer for changing alternating currents into direct were available at that time. The electrical art was ready then to do many of the things which it is doing to-day so well, if it had not been for the opposition of people who were afraid that they would have to scrap some of their direct current apparatus and the plants for manufacturing it, if the alternating current system received any support. A most un-American mental attitude! It was clear to every impartial and intelligent expert that the two systems supplemented each other in a most admirable manner, and that the advancement of one would also advance the other. Men like Elihu Thomson and my colleague Crocker knew that, but ignorance and false notions prevailed in the early nineties, because the captains of electrical industries paid small attention to highly trained electrical scientists. That explains why in those days the barbarous steel cables were still employed to drag cars along Third Avenue, New York, and why in 1893 I saw the preparatory work on Columbus Avenue, New York, for installing additional barbarous steel ropes to drag street-cars. But, fortunately, electrical traction came to the rescue of Columbus Avenue.

During the summer of 1893 I had the good fortune to meet, quite often, William Barclay Parsons, the distinguished engineer, the future builder of the first New York subway, and to-day the distinguished chairman of the Board of Trustees of Columbia University. He passed the summer vacation at Atlantic Highlands, and I at Monmouth Beach, and we used the same steamboat in our occasional trips to New York. His head was full of schemes for the solution of the New York rapid-transit problem, but I observed that his ideas were not quite clear on the question of the electrical power transmission to be employed. A very few years later his ideas had cleared wonderfully. He had visited Budapest in 1894 and had seen there surface cars operated electrically and most satisfactorily by an underground trolley. It was a most instructive object-lesson, but how humiliating it was to the engineering pride of the great United States to consult little Hungary in electrical engineering! The electrical power transmission system employed to-day in the New York subways is practically the same which had been proposed to and accepted by Parsons, the chief engineer, not so many years after our trips to New York, in 1893; it is the electrical power transmission consisting of a combination of the alternating and direct current systems. No fundamentally novel methods were employed which did not exist at the time when the alternating current machine was installed at Sing Sing for the purpose of electrocuting people by the “deadly alternating current.” In less than five years a radical change in popular notions had taken place about a matter which was well understood from the very first by men of higher scientific training, like Stillwell, the chief engineer of the Niagara Power Company, and Sprague, the well-known pioneer in electrical traction, the inventor of the multiple unit system, without which our subway would be practicably impossible.

Four historical events, very important in the annals of the electrical science in the United States, had happened in rapid succession between 1890 and 1894. The first was the successful electrical transmission of power between Lauffen and Frankfurt, in Germany, in 1891; it employed the alternating current system. The second was the decision of the Niagara Falls Power and Construction Company to employ the alternating current system for the transmission of its electrical power; Professor Henry Augustus Rowland, of Johns Hopkins University, as consulting expert of the company, favored this system; another consulting scientific expert, the famous Lord Kelvin, favored the direct current system. The third historical event was the consolidation of the Edison General Electric Company with the Thomson-Houston Company of Lynn, Massachusetts. This consolidation meant the end of the opposition to the alternating current system on the part of people who were most influential in the electrical industries. No such opposition could exist in an electrical corporation where Elihu Thomson’s expert opinion had any weight. The fourth historical event was the Electrical Congress at the World Exposition in Chicago, in 1893. Helmholtz came over as an official delegate of the German Empire, and was elected honorary president of the congress. The subjects discussed at that congress, and the men who discussed them, showed that the electrical science was not in its infancy, and that electrical things were not done by the rule of thumb.

Once I asked Professor Rowland whether anybody had ever suggested to him resigning from Johns Hopkins University on the ground that in favoring the alternating current system for the Niagara Falls Power Transmission plant he had made himself liable to a charge of heresy. “Heresy?” said he; “I thought that my heresy was worth a big fee, and when the company attempted to cut it down the courts sustained my claim.” An interesting bit of history is attached to this. When the Niagara Power and Construction Company objected to the size of the fee which Rowland charged for his services as scientific adviser, and asked for a reduction, the matter was referred to the court. During Rowland’s cross-examination the defendant’s lawyer, the late Joseph Choate, asked him the question: “Who, in your opinion, is the greatest physicist in the United States?” Rowland answered without a moment’s hesitation: “I am.” The judge smiled, but agreed with the witness, and his agreement was in harmony with the opinion of all scientific men. Rowland justified his apparently egotistical answer by the fact that as a witness on the stand he was under oath to speak the truth; he certainly spoke the truth when he testified that he was the leading physicist in the United States.

Rowland’s interest in the electrical science and its technical applications helped much to dissipate the notion, entertained by many, that it was empirical and still in its infancy. Bogus inventors always encouraged this superstition. The attention which Rowland and his former pupil, the late Doctor Louis Duncan, devoted to electrical engineering at Johns Hopkins University helped much to raise the status of electrical engineering. When the new General Electric Company was organized by the consolidation of the Edison General Electric Company and the Thomson-Houston Company, Elihu Thomson became the chief scientific adviser of the new corporation, and its highest court of appeals in scientific matters. I remember telling my colleague, Crocker, that if the Thomson-Houston Company had contributed nothing else than Elihu Thomson to the new corporation it would have contributed more than enough. Thomson, in my opinion, was the American Siemens, and Rowland was the American Helmholtz, of the new era in the history of American industries--the era of close co-operation between abstract science and engineering. With these two men among the leaders of the electrical science and the electrical industry in the United States, the senseless opposition to the alternating current system of power distribution began to wane. It vanished quickly after the Electrical Congress of 1893. The first visible result of the co-operation between abstract science and the technical arts was the splendid power plant at Niagara Falls, and later the electrical power distribution system in the New York subways, in which the alternating and the direct current systems supplemented each other most admirably.

The scientific spirit of Rowland’s laboratory and lecture-room was felt everywhere in the electrical industries; it was felt also in our educational institutions. His and his students’ researches in solar spectra and in other problems of higher physics made that spirit the dominating influence among the rising generation of physical science in America. It was universally acknowledged that Johns Hopkins was a real university. The intellectual movement in favor of higher scientific research, first inaugurated by Joseph Henry, President Barnard of Columbia College, and Doctor John William Draper, in the early seventies, was marching on steadily under the leadership of Rowland when I started my academic career at Columbia, thirty-four years ago, and he led on like a “doughty knight of Troy,” as Maxwell used to call him. It was the spirit of Johns Hopkins which inspired the generation of the early nineties in its encouragement of the movement for the development of the American university. Some enthusiasts at Columbia College went even so far as to advocate the abolition of the college curriculum and the substitution of a Columbia University for Columbia College; I was not among these enthusiasts, because I knew only too well the historical value of Columbia College and of other American colleges. What would the University of Cambridge be without its ancient colleges? College lays the foundation for higher citizenship; the university lays the foundation for higher learning.

Speaking for physical sciences I can say that in those days there was no lack of trained scientists who could easily have extended the work of the American college, and added to it a field of advanced work resembling closely the activity of the European universities. Most of these men had received their higher academic training in European universities, and quite a number of them came from Johns Hopkins. But there were two obstacles: first, lack of experimental-research facilities; second, lack of leisure for scientific research. Rowland and his followers recognized the existence of these obstacles, and demanded reform. Most of the energy of the teachers of physical sciences was consumed in the lecture-room; they were pedagogues, “pouring information into passive recipients,” as Barnard described it. My own case was a typical one. How could I do any research as long as I had at my disposal a dynamo, a motor, an alternator, and a few crude measuring instruments only, all intended to be used every day for the instruction of electrical-engineering students? When the professor of engineering died, in the summer of 1891, a part of his work, theory of heat and hydraulics, was assigned to me. The professor of dynamics died a little later, and his work also was transferred to me. I was to carry the additional load of lecture-room work temporarily, but was relieved from it, in part only, after several years. As a reward my title was advanced to adjunct professor, with an advance of salary to two thousand five hundred dollars per annum. But in return for this _royal_ salary I had to lecture three to four hours each forenoon, and help in the electrical laboratory instruction in the afternoons. While this pedagogic load was on my back scientific research could not be seriously thought of. My young colleagues in other colleges were similarly situated. This overloading of young scientists with pedagogic work threatened to stunt, and often did stunt, their growth and also the growth of the rising American university. “Let chairs be founded, sufficiently but not luxuriously endowed, which shall have original research for their main object and ambition,” was the historic warning which Tyndall addressed to the American people in 1873, but in 1893 there was little evidence that it was heeded anywhere outside of Johns Hopkins University. But there they had Rowland and a number of other stars of the first magnitude who had succeeded Joseph Henry, Barnard, and Draper as leaders of the great movement in favor of higher scientific research. In 1883 Rowland delivered a memorable address as vice-president of one of the sections of the American Association for the Advancement of Science. It was entitled, “A Plea for Pure Science,” and described the spirit not only of Johns Hopkins of those days but also of all friends of higher learning in science. That spirit was advocated here by Tyndall in 1872-1873, and under Rowland’s leadership it was bound to win our battle for higher ideals in science. The people of the United States owe a great debt of gratitude to Johns Hopkins for the leadership in that great movement which, as we see to-day, has produced a most remarkable intellectual advancement in this country. Nearly thirty years ago I heard Rowland say in a public address: “They always say in Baltimore that no man in that city should die without leaving something to Johns Hopkins.” When he said it he knew that Johns Hopkins was very poor. It is poorer to-day than ever, and no rich man in the United States should die without leaving something to Johns Hopkins, the pioneer university of the United States.

Rowland said once that lack of experimental facilities and of time was not a valid excuse for neglecting entirely scientific research. I agreed with that opinion; neglect breeds indifference, and indifference degenerates into atrophy of the spirit of inquiry. The alternating current machine of the electrical engineering laboratory at Columbia was free in the evenings, and so was my time; that is, if my wife should not object, and, being a noble and unselfish woman, she did not object. With the assistance of several enthusiastic students, among them Gano Dunn, to-day one of the most distinguished engineers in the United States, I started investigating the passage of electricity through various gases at low pressures, and published two papers in the _American Journal of Science_. I soon discovered that most of my results had been anticipated by Professor J. J. Thomson, of Cambridge, who, in all probability, had received his inspiration from the same source from which I had received mine. He not only had anticipated me but, moreover, he showed a much better grasp of the subject than I had, and had much better experimental facilities. I decided to leave the field to him, and to watch his beautiful work from the outside. It was a wise decision, because it prepared me to understand the epoch-making discoveries in this field which were soon to be announced, one in Germany and one in France. I turned my attention to another field.

I must mention, however, one of the results which Thomson had not anticipated and which created quite an impression among astronomers. I noticed a peculiar appearance in the electrical discharge proceeding from a small metal sphere which was located in the centre of a large glass sphere containing air at low pressure. The discharges looked very much like the luminous corona of the sun which astronomers observe during eclipses, and which was always a mysterious puzzle in solar physics. Pasting a tin-foil disk on the glass sphere, so as to hide the metal sphere and see only the discharge proceeding from it, I photographed the appearance of the discharge and obtained the pictures given opposite page 294. The resemblance of these photographs to those of the two types of the solar corona is most striking. This is what I said about it at that time:

“The bearing which these experimental results may have upon the theory of the solar corona I prefer to leave to others to decide. That they may prove a suggestive guide in the study of solar phenomena seems not unreasonable to expect.”

In a communication read later before the New York Academy of Sciences I was much bolder, having previously discussed the subject with my friends at Johns Hopkins and with the late Professor Young, the famous astronomer at Princeton. I soon found myself advocating strongly the electromagnetic theory of solar phenomena. A German professor, Ebert by name, a well-known authority on electrical discharges in gases, took me very seriously indeed, which was very flattering, but he claimed priority. I had no difficulty in establishing my priority through the columns of _Astronomy and Astro-Physics_, one of whose editors was George Ellery Hale, to-day the distinguished director of Mount Wilson Observatory. I was indeed fortunate to make his acquaintance during that period when both he and I were very young men. His influence prevented me from running wild with my electromagnetic theory of solar phenomena. Thanks to the splendid astro-physical researches at the Mount Wilson Observatory in California under Doctor Hale’s direction, we know to-day that enormous electrical currents circulate on the surface of the sun, and we know also from other researches that negative electricity is shot out from all hot bodies, even from those not nearly as hot as the sun, and that the solar corona is, in all probability, closely related to this electrical activity on the sun.

After giving up the subject of electrical discharges in gases I looked around for another problem of research which I could manage with my meagre laboratory facilities. Rowland had found distortions in an alternating current when that current was magnetizing iron in electrical power apparatus. This distortion consisted of the addition of higher harmonics to the normal harmonic changes in the current. This reminded me of harmonics in musical instruments and in the human voice. Helmholtz was the first to analyze the vowels in human speech by studying the harmonics which they contained. The vowel o, for instance, sung at a given pitch, contains in addition to its fundamental pitch--say one hundred vibrations per second--other vibrations the frequencies of which are integral multiples of one hundred, that is two, three, four, ... hundred vibrations per second. These higher vibrations are called harmonics of the fundamental. Helmholtz detected these harmonics by the employment of acoustical resonators; it was an epoch-making research. I proceeded to search for a similar procedure for the analysis of Rowland’s distorted alternating currents, and I found it. I constructed electrical resonators based upon dynamical principles similar to those in the acoustical resonators employed by Helmholtz. These electrical resonators play a most important part in the radio art of to-day, and a few words regarding their operation seem desirable. In fact, there is to-day a cry from the Atlantic to the Pacific on the part of millions of people who wish to know what they are really doing when they are turning a knob on their radio-receiving sets in order to find the correct wave length for a certain broadcasting station. I am responsible for the operation, and I owe them an explanation of it.

The mass and form of an elastic body, say a tuning-fork, and its stiffness determine the pitch, the so-called _frequency_ of vibration. When a periodically varying force, say a wave of sound, acts upon the tuning-fork, the maximum motion of the prongs will be produced when the pitch or frequency of the moving force is equal to the frequency of the tuning-fork. The two are said then to be in resonance, that is, the motion of the fork resonates to or synchronizes with the action of the force. Every elastic structure has a frequency of its own. The column of air in an organ-pipe has a frequency of its own; so has the string of a piano. One can excite the motion of each by singing a note of the same frequency; a note of a considerably different frequency excites practically no motion at all. Acoustical resonance phenomena are too well known to need here any further comment. There are also electrical resonance phenomena very similar to those of acoustical resonance. If you understand one of them there is no difficulty in understanding the other.

If an electrical conductor, say a copper wire, is coiled up so as to form a coil of many turns, and its terminals are connected to a condenser, that is to conducting plates which are separated from each other by insulating material, then the motion of electricity in that conducting circuit is subject to the same laws as the motion of the prongs of a tuning-fork. Every motion, whether of electricity or of matter, is determined completely by the force which produces the motion, and by the forces with which the moving object reacts against the motion. If the law of action of these several forces is the same in the case of moving matter as in the case of moving electricity, then their motions also will be the same. The moving forces are called the _action_ and the opposing forces are called the _reaction_, and Newton’s third law of motion says: _Action is equal to the opposing reaction_. I always considered this the most fundamental law in all physical sciences. It is applicable to all motions no matter what the thing is which moves, whether ponderable matter or imponderable electricity. Twenty-six years ago a student of mine, Albert R. Gallatin, brother of the present park commissioner of New York, presented a large induction coil to the electrical laboratory at Columbia College in recognition of my services to him, because, he said, this formulation of the fundamental law in the electrical science, which I have just given, made everything very clear to him. This was most encouraging to a young professor, and it goes without saying that ever since that time he and I have been warm friends. He is a banker and I am still a professor, but the interest in the fundamental principles in physical sciences are a strong bond of union between us.

The electrical force which moves the electricity in the circuit, just described, experiences two principal reactions. One reaction is due to the lines of electrical force which, attached to the electrical charge on the condenser plates, are crowded into the insulating space between these plates. This reaction corresponds to the elastic reaction of the prongs of the tuning-fork, and follows the same law. In the case of the tuning-fork the _elastic reaction is proportional to the displacement_ of the prongs from their normal position; in the electrical case the reacting force is proportional to the electrical charges which have been pulled apart, the negative from the positive, and driven to the plates of the condenser. Call this separation _electrical displacement_, and the law can be given the same form as above, namely: _The reacting force is proportional to the electrical displacement_. The greater the distance between the plates, and the smaller their surface, the greater is the reaction for a given electrical displacement. By varying these two quantities we can vary the electrical yielding, the so-called capacity, of the electrical condenser. This is what you do when you turn the knob and vary the capacity of the condenser in your receiving set.

The moving prongs have a momentum, and a change in the momentum opposes a reacting force, the so-called inertia reaction, which is equal to the rate of this change. This was discovered by Galileo over three hundred years ago. We experience the operation of this law every time we bump against a moving object. The Irish sailor who, after describing the accident which made him fall from the mast, assured his friends that it was not the fall which hurt him but the sudden stop, appreciated fully the reacting force due to a rapid change of momentum. Every boy and girl in the public schools should know Galileo’s fundamental law, and they would know it if by a few simple experiments it were taught to them. But how many teachers really teach it? How many of my readers really know that law? Just think of it, what an impeachment it is of our modern system of education to have so many intelligent men and women, boys and girls, ignorant of so fundamental a law as that which Galileo discovered so long ago!

The moving electricity has a momentum. The magnetic lines of force produced by this motion are a measure of this momentum. Their change is opposed by a reacting force equal to the rate of this change. This was discovered by Faraday nearly a hundred years ago. The larger the number of turns in the coil of wire the larger will be the momentum for a given electrical motion, that is, for a given electrical current. But how can anybody understand very clearly this beautiful law, discovered by Faraday, who does not understand Galileo’s simpler discovery? The fact that electricity, just like matter, has inertia, and that both obey the same law of inertia, is one of the most beautiful discoveries in science. Whenever I thought that so many intelligent and cultured people knew nothing about it I rebelled against the educational system of modern civilization.

The motion of electricity in the conductor described above overcomes reacting forces which follow the same laws as the motion of the elastic prongs of the tuning-fork. The motion of one has, therefore, an analogy in the motion of the other. In an electrical circuit having a coil and a condenser the moving electricity has a definite inertia and a definite electrical stiffness; hence it will have a definite pitch or frequency for its vibratory motion, just like a tuning-fork; it will act as a resonator. It is obvious, therefore, that an electrical resonator, the pitch of which can be adjusted by adjusting its coil or its condenser or both, is a perfect parallel to the acoustical resonator. By means of an electrical resonator of this kind, having an adjustable coil and an adjustable condenser, I succeeded in detecting every one of the harmonics in Rowland’s distorted alternating currents, in the same manner in which Helmholtz detected the harmonics in the vowel sounds, but with much greater ease, because the pitch of an electrical resonator can be very easily and accurately changed by adjusting its coil and condenser. There are millions of people to-day who are doing that very thing when they are turning the knobs on their radio receiving sets, adjusting them to the wave-length of the transmitting station. The expression, “adjusting them to the pitch or frequency of the transmitting station,” is much better, because it reminds the operator of the analogy existing between acoustical and electrical resonance. The procedure was inaugurated thirty years ago in the “cowshed” of old Columbia College. I called it “electrical tuning” and the name has stuck to it down to the present time. The word “tuning” was suggested by the operation which the Serbian bagpiper performs when he tunes up his bagpipes, which I watched with a lively interest in my boyhood days. Those early impressions had made acoustical and electrical resonance appear to me later as obvious things.

The results of this research were published in the _American Journal of Science_ and also in the _Transactions of the American Institute of Electrical Engineers for 1894_. They, I was told, had never been anticipated; and they confirmed fully Rowland’s views concerning the magnetic reaction of iron when subjected to the magnetic action of an alternating current. When Helmholtz visited this country in 1893, I showed him my electrical resonators and the research which I was conducting with their assistance. He was quite impressed by the striking similarity between his acoustical resonance analysis and my electrical resonance analysis, and urged me to push on the work and repeat his early experiments in acoustical resonance, because my electrical method was much more convenient than his acoustical method.

Helmholtz was always interested in the analysis as well as in the synthesis of vibrations corresponding to articulate speech. The telephone and the phonograph were two inventions which always enjoyed his admiring attention. During his visit in America he looked forward with much pleasure to meeting Graham Bell and Edison. The simplicity of their inventions astonished him, because one would hardly have expected that a simple disk could vibrate so as to reproduce faithfully all the complex vibrations which are necessary for articulation. He spent a Sunday afternoon as my guest at Monmouth Beach and in the course of conversation I told him what impression the telephone had made upon me when I first listened through it. It happened during the period when I was serving my apprenticeship as greenhorn, and when I was trying hard to master the articulation of the English language. The telephone plate repeated perfectly everything spoken at the other end, and I said to myself: “These Americans are too clever for me; they can make a plain steel plate articulate much better than I can ever expect to do it with all my speaking organs. I had better return to Idvor and become a herdsman again.” Helmholtz laughed heartily and assured me that the articulating telephone plate had made a similar impression upon him, although he had spent several years of his life studying the theory of articulation. “The phonograph disk is just as clever as the telephone disk,” said Helmholtz, “perhaps even more so, because it has to dig hard while it is busily talking.”

My scientific friends in New York saw in the construction of my electrical resonator and in its employment for selective detection of alternating currents of definite frequency a very suitable means for practising harmonic telegraphy, first suggested by Graham Bell, the inventor of the telephone. They finally persuaded me to apply for a patent and I did so. I often regretted it, because it involved me in a most expensive and otherwise annoying legal contest. Two other inventors had applied for a patent on the same invention. One of them was an American, and the other a French inventor, and each of them was backed by a powerful industrial corporation. A college professor with a salary of two thousand five hundred dollars per annum cannot stand a long legal contest when opposed by two powerful corporations; but it is a curious psychological fact that when one’s claim to an invention is disputed he will fight for it just as a tigress would fight for her cub. The fight lasted nearly eight years and I won it. I was declared to be the inventor, and the patent was granted to me. But a patent is a piece of paper worth nothing until somebody needs the invention. I waited a long time before that somebody came, and when he finally showed up I had almost forgotten that I had made the invention. In the meantime I had nothing but a piece of paper for all my pains, which nearly wrecked me financially.

Just about that time the newspapers reported that a young Italian student by the name of Marconi, while experimenting with Hertzian waves, had demonstrated that a Hertzian oscillator will send out electrical waves which will penetrate much longer distances when one of its sides is connected to earth. “Of course it will,” said I, “the grounded oscillator takes the earth into closer partnership.” When as a herdsman’s assistant on the pasturelands of my native Idvor I stuck my knife into the ground and struck its wooden handle, I knew perfectly well that the ground was a part of the vibrating system, and that the sound-producing stroke was taken up by the ground much better than when I struck the knife-handle without sticking the knife into the ground. But I also knew that unless the boy who was listening pressed his ear against the ground he would not hear very much. It was, therefore, quite obvious to me that the best detector for a Hertzian oscillator which is grounded must be another Hertzian oscillator which is also connected to the ground. Grounding of the sending and of the receiving Hertzian oscillators was in fact the fundamental claim of the Marconi invention. Marconi, in my opinion, was unwittingly imitating the young herdsmen of Idvor when, figuratively speaking, he stuck his electrical knives into the ground for the purpose of transmitting and receiving electrical vibrations, but the imitation was a very clever one; very obvious indeed as soon as it was pointed out, like all clever things.

Every now and then we are told that wireless signals might be sent some day to the planet Mars. The judgment of a former herdsman of Idvor considers these suggestions unscientific for the simple reason that we cannot get a ground on the planet Mars and, therefore, cannot take it into close partnership with our Hertzian oscillators. Without that partnership there is no prospect of covering great distances. A very simple experiment will illustrate this. Scratch the wood of a pencil and ask your friends who are sitting around a table whether they hear the scratching. They will say “No.” Put the pencil on the table and scratch it again; your friends will tell you that they can hear it faintly. Ask them to press their ears against the table and they will tell you that the scratching sound is very loud. In the third case the pencil, the table, and the ears of your friends are all one closely interconnected vibratory system. Every herdsman of Idvor would interpret correctly the physical meaning of this experiment. “If Marconi had waited just a little longer I should have done his trick myself,” I said jokingly to Crocker, and then I temporarily dismissed the matter from my mind as if nothing had happened. But I was fairly confident that my electrical resonators would some day find a useful application in this new method of signalling, and Crocker was even more hopeful than I was. I turned my attention to another problem and would have completed its solution, if my work had not been interrupted by the announcement of a most remarkable discovery made in Germany, I mean the discovery of the Roentgen rays.

I cannot describe the effects of this epoch-making discovery without referring again to great Helmholtz. It was due to his initiative that Hertz took up the research of electrical oscillations, which suggested to Marconi their technical application. This started a new technical art, wireless telegraphy, which developed into the radio art. Without Helmholtz, not only the experimental verification of the Faraday-Maxwell electromagnetic theory but also the radio art might have been delayed quite a long time. I shall point out now that the great discovery of the Roentgen rays also was due in a great measure to the initiative of Helmholtz.

While in Berlin I was conducting a research upon vapor pressures of salt solutions. For this purpose I needed the assistance of a clever glass-blower. A Herr Mueller was recommended to me by the people of the Physical Institute. I paid frequent visits to him, not only because I liked to watch his wonderful skill in glass-blowing, but also because he knew and entertained me often with the history of a remarkable physical research which had been carried out by Doctor Goldstein, a Berlin physicist, under the auspices of the German Academy of Sciences, Herr Mueller, the glass-blowing artist, assisting.

The motion of electricity through rarefied gases was first extensively studied in Germany in the fifties and sixties by several investigators. Hittorf was one of them, and I mention him here for reasons given later. The English physicists took up the subject a little later, and among them Crookes did the most distinguished work. His tubes with a very high vacuum gave brilliant cathode rays, first discovered by Hittorf, which produced among other things the well-known phosphorescence in vacuum tubes made of uranium glass. In spite of the surpassing beauty of the electrical phenomena in vacuum tubes revealed by Crookes’s experiments, no final and definite conclusions could be drawn from them toward the end of the seventies. But he was undoubtedly the first who correctly inferred that the cathode rays were small electrified particles moving with very high velocity. This inference proved to be of very great importance. In 1893 Lord Kelvin said: “If the first step toward understanding the relations between ether and ponderable matter is to be made, it seems to me that the most hopeful foundation for it is knowledge derived from experiment on electricity in high vacuum.” This was the very opinion which Helmholtz had formulated fifteen years earlier, and he persuaded the German Academy of Sciences to make a special grant for a thorough experimental review of the whole field of research relating to electrical motions in high vacua. Doctor Goldstein was selected to carry out this work. Mueller was his glass-blower. The most important result of this work was the discovery of the so-called _Canal Rays_, that is, motion of positive electricity in the direction opposite to the motion of negative electricity, the latter being the cause of the _cathode rays_. To get that result Mueller had to make innumerable vacuum tubes of all sorts of shapes. He told me that if all these tubes could be resurrected they would fill the house in which his shop was located. “But the grand result was worth all the trouble, and I am proud that I did all the glass-blowing,” said Mueller, with a triumphant light in his eyes, and his beaming countenance testified that he felt what he said. He was an artisan who loved his craft; and, judging from his remarkable knowledge of all the vacuum-tube researches which had been conducted up to the time of his co-operation with Doctor Goldstein, I inferred that he was a unique combination of the science and the art involved in the job which he was doing for Doctor Goldstein. Mueller was the first to arouse my interest in the results of vacuum-tube researches, and I always considered him one of my distinguished teachers in Berlin. New knowledge is not confined to the lecture-rooms of a great university; it can often be found in most humble shops, treasured by humble people who are quite unconscious that they are the guardians of a precious treasure. Mueller was one of these humble guardians.

The importance of Goldstein’s work was due principally to the fact that it brought into the field three other German physicists of great acumen. The first one was Hertz. Several years after he had completed his splendid experimental verification of the Faraday-Maxwell electromagnetic theory, he showed that the cathode rays penetrated easily through thin films of metal, like gold and aluminum foil, although these films were perfectly opaque to ordinary light. It was a novel and most important contribution to our knowledge of cathode rays, and would have been followed up by more additional knowledge if Hertz had not died on January 1, 1894, at the age of thirty-six. Helmholtz died several months later. Science never suffered a greater loss in so short an interval of time. Helmholtz met with an accident on the ship on his return trip from the United States in 1893. He never completely recovered, although he lectured at the University of Berlin until a few days before his sudden death in the mid-summer of 1894. Autopsy revealed that one side of his brain was and had been in a pathological state for a long time, but nobody had ever observed that his intellectual power had shown any signs of decay. It is a pity that he did not live another two years; he would have seen what he told me during his visit here he longed to see, and that is an electrified body moving at a very high velocity suddenly reversing its motion. That, he thought, might furnish a direct experimental test of the mobility of ether. The discovery described below furnished such a body.

Hertz’s work was continued and greatly extended by Professor Lenard of the University of Kiel. He would have undoubtedly reached the final goal if Roentgen had not announced, in December, 1895, that he, experimenting with Lenard vacuum tubes, had discovered the X-rays. This discovery marked the last step in the survey which Goldstein, under the initiative of Helmholtz, had undertaken some fifteen years before Roentgen had entered the field of electrical discharges in high vacua. It was a great triumph for German science. The science of electrical discharges in rarefied gases was started in Germany and in less than forty years it had reached there its highest point. It is a science which may justly be said to have been “made in Germany,” just as the science of radiation. It started a new and most remarkable era in physical sciences by extending the meaning of the Faraday-Maxwell electromagnetic theory.

No other discovery within my lifetime had ever aroused the interest of the world as did the discovery of the X-rays. Every physicist dropped his own research problems and rushed headlong into the research of the X-rays. The physicists of the United States had paid only small attention to vacuum-tube discharges. To the best of my knowledge and belief I was at that time the only physicist here who had had any laboratory experience with vacuum-tube research, and I got it by overtime work in the electrical-engineering laboratory of Columbia College. I undertook it because my intercourse with Mueller, the glass-blower of Berlin, directed my attention to this field of research, and particularly because I did not see that with the equipment of that laboratory I could do anything else. I decided, as mentioned above, to leave the field to Professor J. J. Thomson, of Cambridge, and to watch his work. When, therefore, Roentgen’s discovery was first announced I was, it seems, better prepared than anybody else in this country to repeat his experiments and succeeded, therefore, sooner than anybody else on this side of the Atlantic. I obtained the first X-ray photograph in America on January 2, 1896, two weeks after the discovery was announced in Germany.

Many interesting stories have been told about the rush to the West during the gold-fever period, caused by the discovery of gold in the far West. The rush into X-ray experimentation was very similar, and I also caught the fever badly. Newspaper reporters and physicians heard of it, and I had to lock myself up in my laboratory, which was in the cellar of President Low’s official residence at Columbia College, in order to protect myself from continuous interruptions. The physicians brought all kinds of cripples for the purpose of having their bones photographed or examined by means of the fluorescent screen. The famous surgeon, the late Doctor Bull of New York, sent me a patient with nearly a hundred small shot in his left hand. His name was Prescott Hall Butler, a well-known lawyer of New York, who had met with an accident and received in his hand the full charge of a shotgun. He was in agony; he and I had mutual friends who begged me to make an X-ray photograph of his hand and thus enable Doctor Bull to locate the numerous shot and extract them. The first attempts were unsuccessful, because the patient was too weak and too nervous to stand a photographic exposure of nearly an hour. My good friend, Thomas Edison, had sent me several most excellent fluorescent screens, and by their fluorescence I could see the numerous little shot and so could my patient. The combination of the screen and the eyes was evidently much more sensitive than the photographic plate. I decided to try a combination of Edison’s fluorescent screen and the photographic plate. The fluorescent screen was placed on the photographic plate and the patient’s hand was placed upon the screen. The X-rays acted upon the screen first and the screen by its fluorescent light acted upon the plate. The combination succeeded, even better than I had expected. A beautiful photograph was obtained with an exposure of a few seconds. The photographic plate showed the numerous shot as if they had been drawn with pen and ink. Doctor Bull operated and extracted every one of them in the course of a short and easy surgical operation. Prescott Hall Butler was well again. That was the first X-ray picture obtained by that process during the first part of February, 1896, and it was also the first surgical operation performed in America under the guidance of an X-ray picture. This process of shortening the time of exposure is now universally used, but nobody gives me any credit for the discovery, although I described it in the journal _Electricity_, of February 12, 1896, before anybody else had even thought of it. Prescott Hall Butler was much more appreciative and he actually proposed, when other offers to reward me for my efforts were refused, to establish a fellowship for me at the Century Club, the fellowship to entitle me to two toddies daily for the rest of my life. This offer also was refused.

On March 2, 1896, the late Professor Arthur Gordon Webster, of Clark University, Worcester, Massachusetts, addressed a letter to the _Worcester Gazette_, from which I quote:

Sunday morning I went with Professor Pupin to his laboratory to try the effect of a fluorescent screen in front of the plate. I placed my hand under the bulb and in five minutes the current was stopped.... The result was the best plate that I had yet seen.... One who has tried the experiments and seen how long it takes to obtain a good result can judge of an improvement. I think that Doctor Pupin should enjoy the credit of having actually ... shortened the time of exposure ten and twenty times.

A description of the improvement, which I published in final form in _Electricity_, of April 15, 1896, ends with the following sentence:

My only object in working on the improvement of the Roentgen ray photography was for the purpose of widening its scope of application to surgical diagnosis. I think that I have succeeded completely and I wish full credit for the work done.

My friends suggested that I apply for a patent on the procedure and enforce recognition that way, but I was having one expensive experience in the patent office with my electrical resonators and did not care to add another.

The question of reflection and refraction of the X-rays had to be answered, and several strange claims were brought forward by investigators. My investigations of this matter, aided by Thomas Edison’s most efficient fluorescent screen, resulted in a discovery, which, in a communication to the New York Academy of Sciences, on April 6, 1896, I summed up as follows: “_Every substance when subjected to the action of X-rays becomes a radiator of these rays_.” The communication was published in several scientific journals, like _Science_ and _Electricity_, and no statement can claim the discovery of the now well-known secondary X-ray radiation more clearly than the one given above. But of this matter I shall speak a little later.

Looking up some data lately I found that I had finished writing out these communications relating to my X-ray research on April 14, 1896. I also found a reprint of an address delivered before the New York Academy of Sciences in April, 1895, and published in _Science_ of December 28, 1895, at the very time when the X-ray fever broke out. It was entitled: “Tendencies of Modern Electrical Research.” But the X-ray fever prevented me from reading it when it was published. I saw it three months later, but never again since that time, and I had forgotten that I had ever composed it. I find now that the picture which I had drawn then of the growth of the electromagnetic theory is in every detail the same as that which I have given in this narrative. Both of them are due to the lasting impressions received in Cambridge and in Berlin. Evidently these impressions are just as strong to-day as they were twenty-eight years ago, proving that the tablets of memory have a mysterious process of preserving their records. I remember that on April 14, 1896, I did not go to the laboratory, but stayed at home and reflected, and read my address mentioned above. I took an inventory of what I had done during my six years’ activity at Columbia and I closed the books satisfied with the results. My wife, who had helped me, writing out my reports, lectures, and scientific communications, and who knew and watched every bit of the work which I was doing, also was satisfied, and congratulated me. My colleague Crocker, I knew, was satisfied, and so were all my scientific friends, and that was a source of much satisfaction. But nothing makes one as happy as his own honest belief that he has done his best.

XI

THE RISE OF IDEALISM IN AMERICAN SCIENCE

I must make a digression now, to arrange suitable contacts between the preceding parts of my narrative and its concluding chapters. The main object of my narrative has been to describe the rise of idealism in American science, and particularly in physical sciences and the related industries. I witnessed this gradual development; everything I have written so far is an attempt to qualify as a witness whose testimony has competence and weight. But there are many other American scientists whose opinions in this matter have more competence and weight than my opinion has. Why, then, should a scientist who started his career as a Serbian immigrant speak of the idealism in American science, when there are so many native-born American scientists who know more about this subject than I do? Those who have read my narrative so far may answer this question. I shall only point out now that there are certain psychological elements in this question which justify me in the belief that occasionally an immigrant can see things which escape the attention of the native. Seeing is believing; let him speak who has the faith, provided he has a message to deliver.

* * * * *

A foreign-born citizen of the United States has many occasions to sing praises of the virtues of this country which the native-born citizen has not. Such occasions arise whenever the foreign-born citizen revisits his native land and hears opinions about America which are based upon European prejudice born of ignorance. On these occasions he can, if the spirit moves him, say many things with much more grace than a native American could. The spirit will move him if his naturalization means that he knows America’s traditions and embraces their precepts with sincere enthusiasm. Statements which, coming from a native American, might sound as boasts and bragging, may and often do sound different when they are made by a naturalized American citizen. I have had quite a number of experiences of this kind; one of them deserves mention here.

Four years ago, while visiting my native land, I was invited to attend a festive public meeting in a town not far from my native village. It was the town of Panchevo, where in my boyhood days I went to school, and where from my Slovenian teacher, Kos, I had heard for the first time of Benjamin Franklin and of his kite. The earliest parts of this narrative show that many memories of my boyhood days had nourished in my heart an affectionate regard for this historic town. Panchevo reciprocated, and hence the invitation. There was another reason. In March of 1919, the chairman of the Yugoslav delegation at the Paris peace conference invited me to go to Paris, expecting that with my knowledge of the English language and of the Anglo-Saxon mentality I could probably assist the delegation in its work. I spent seven weeks in Paris. The result, I was assured by Premier Pashitch of Serbia, was very satisfactory; and he invited me to go to Belgrade as guest of the government, for the purpose of studying the condition of the war orphans in Serbia. This study resulted in the organization of the Serbian Child Welfare Association of America, whose splendid work is known and appreciated in every part of the Serbian nation. When Panchevo heard that I was in Belgrade it sent me the invitation.

The literary society of Panchevo, called the Academy, had arranged a gala public session, and the occasion was the “Wilson Day,” which the town was celebrating. The orator of the day was a young Slovene, a learned lawyer and man of letters. The subject of his oration was: “President Wilson and his fourteen points.” He wound up his splendid eulogy of President Wilson by exclaiming: “_President Wilson is an oasis of idealism in the endless desert of materialism_.” The image of my old friend Bilharz, the hermit of Cortlandt Street, suddenly appeared before me, and his favorite phrase “American materialism” rang violently in my ears. I was afraid that the United States of America would be understood to be a part of the endless desert mentioned by the speaker, and the possibility of such an inference I did not like. A most enthusiastic and long-continued applause greeted this oratorical climax, and before the applause was over the chairman, who was the mayor of the town, approached me and asked whether I should like to address a few words to the great assembly of the intellectuals of the town. “I not only like to do it,” said I, “but I insist upon it.” The chairman looked pleased, because he could not help observing that the orator’s concluding figure of speech had stirred me up considerably, and that my response to it might add a few lively notes to the rather monotonous programme of the Academy session.

I repeat here some of the sentiments which I expressed on that occasion:

President Wilson is an idealist, and his idealism commands my deepest respect and admiration. I deny, however, that he represents an “oasis of idealism in an endless desert of materialism,” that is, if the United States of America are understood to be a part of this endless desert. I am sure that in this town, liberated only a few months ago from the Austrian yoke, the expression “materialism” cannot refer to the United States of America. Two million American soldiers were fighting on the Western front when, a few months ago, the armistice was signed; several million more were waiting in America for their turn to join the ranks of the allied armies in France. American industries and American savings made a supreme effort to brace up the allied cause, and the war was won. Go to Paris now and watch the proceedings at the peace conference, as I was doing during the last seven weeks, and you will find that America asks for no territories, for no mandates, and for no onerous compensations. It is the only great power there which preaches moderation, and demands unreservedly full justice for the little nations. Yugoslav Dalmatia, Istria, Goricia, and Fiume had been, in a period of stress, bartered away by some of our allies; America is to-day the only fearless champion of your claims to these Yugoslav lands. American men and women hastened to every front, and there, amid many perils and discomforts, they nursed the sick and the wounded. They fed the hungry and clothed the naked and the destitute. This they did even before America had entered the world war. Need I remind you that it was an American mission which, in 1915, saved Serbia from the destructive ravages of typhus, and that several Americans, victims of these very ravages, are now buried in Serbia’s soil? To-day you will find Americans even in the countries of our former enemies, in Germany, Austria, and Hungary, doing the work of mercy and of charity. The name of Hoover is just as well known and beloved in Vienna and Budapest as it is in Belgium. A country of materialism cannot display that spirit which America has displayed during this war. Let the idealism of President Wilson remind you of American idealism.

The phrase “American materialism” is an invention of ill-informed Europe; but the European who has lived in the United States, and has had the good fortune to catch the spirit of America, revolts whenever he hears the untutored European mind utter that phrase. Read the history of the United States from its earliest beginnings, when the Pilgrim fathers landed at Plymouth Rock, three hundred years ago, and you will find that idealism runs through it from beginning to end. The Pilgrim fathers themselves were idealists, who undertook the perilous voyage “for the glory of God and the advancement of the Christian faith.”

A hundred and fifty years later the Continental Congress of the colonies issued, at Philadelphia, the “Declaration of Colonial Rights,” and this declaration, as well as the documents accompanying it and addressed to the people of the United Kingdom and of British America, breathes the spirit of lofty idealism. The same Congress in 1775 issued another declaration, setting forth causes which forced the American colonies to take up arms; and in 1776 it issued the Declaration of Independence, which announced to the world the ideals for the attainment of which the colonists were ready to sacrifice their lives. No other human documents ever stated so clearly and so definitely the “divine right of man” as these documents did. The men who composed these documents were not ordinary men; they were idealists of the highest type. Read the lives of Washington, Hamilton, Franklin, Jay, Jefferson, and of other leaders of the American Revolutionary period, and you will find what a wonderful power idealism has when the destiny of a young nation hangs in the balance. But when the struggle was over, after the victory had been won, the leader of the new nation, immortal Washington, assumed the supreme executive office of the land and retired from it after two terms of service with a spirit of dignity and of humility which has no equal in human history. His Farewell Address to the American people, advocating the practice of idealism by the cultivation of religion, morality, patriotism, good faith, and justice toward all nations, is an echo of the voice of idealism which was the driving power of the American Revolution.

The idealism of the Revolutionary period was the guiding star of the American patriots of the stormy period preceding the Civil War. One of them, Daniel Webster, was a youth of seventeen when Washington died, and he knew personally some of the great leaders of the Revolutionary period, like Jefferson and Adams. He certainly caught by direct contact the idealism of this period. Read his speeches, as I have read them during my apprenticeship days in America, and you will understand what I mean by American idealism, if this war has not shown it to you better than any words of mine can do it. Webster’s idealism was in the hearts of men of his generation, who, under the great leadership of Lincoln, one of the greatest among American idealists, conducted the Civil War and preserved the American Union. Lincoln’s immortal words: “With malice toward none, with charity for all,” will forever remind the world of the idealism which was in the hearts of the American people who fought for the preservation of the American Union. President Wilson is one of the best biographers of George Washington, and he also published a splendid study of the constitutional government of the United States. No profound student of these themes can escape becoming an exalted idealist. His speeches, which during the World War he addressed to the American people and to the whole world, are sermons on American idealism, which have guided the people of the United States from the very beginning of their history; but some of you in Europe never understood it. The world war has made you eager to listen to every word which inspires your anxious hearts with new hopes. President Wilson’s words and his acts at the Paris peace conference inspire you with these new hopes, and hence this Wilson Day, an honor to him and a credit to you. In honoring him you are honoring the idealism of the American people, for which act I am most grateful to you.

It was here in Panchevo that I first heard of Benjamin Franklin, nearly fifty years ago; to-day I deliver to you, people of Panchevo, a greeting from Franklin’s native land and a message that the cultivation of American idealism is the most powerful arm for the defense of the destiny of your young nation.

Hamilton Fish Armstrong, our military _attaché_ in Belgrade at that time, was present at the meeting. He did not understand a word of my address, because it was delivered in Serbian, but he assured me that, judging by appearances, it must have been at least as good as my address in Princeton in the beginning of the World War in 1914; he was then a senior at Princeton College. The Princeton address was a eulogy of Serbian idealism, which I had imported into America when I landed at Castle Garden in 1874; the Panchevo address was a eulogy of American idealism, which I had brought back to Panchevo forty-five years later. I must confess, however, that, twenty-five years earlier, the above address was delivered in substance to Protoyeray Zhivkovich, the poet-priest of Panchevo, when after graduating at Columbia in 1883 I returned for the first time to my native village. On that occasion the poet said, and here I quote from an earlier chapter of my narrative:

Tell your mother that I am happy to bear the whole responsibility for your wandering away to distant America. It is no longer distant; it is now in my heart; you have brought America to us. It was a new world in my terrestrial geography; it is now a new world in my spiritual geography.

I often think of these words now, and I firmly believe that there are many millions of people in Europe to-day who think that America is a new world in their spiritual geography. The people in Panchevo, I am certain, think so. But it needed a world war to eliminate from their minds the old superstition that this is the land of “American materialism.” The world pendulum has swung the other way, and I often wonder whether we can live up to the very high reputation which we enjoy in the opinion of a large part of the world, which now knows our virtues but does not know our shortcomings.

A short time after the Panchevo celebration, a number of scientists of the University of Belgrade, members of the Royal Serbian Academy, invited me to an informal conference, and asked me to tell them something about American science and its National Research Council in Washington. I do not think that on that occasion my discourse on this most interesting topic impressed my Serbian friends as strongly as my Panchevo discourse did. For a long time after this conference I thought of many things that I might have said, but did not say. The more I thought about it the more I was dissatisfied. I was informed several months after this conference that one of the Serbian scientists present remarked to a mutual friend that from my Panchevo address on American idealism he had been led to believe that at the Belgrade conference I would say something about idealism in American science. But I said nothing, and he inferred, therefore, that there could not be much idealism in American science, a thing which he had always suspected. Many European scientists suspected that long before he did. That permissible inference of the Serbian scientist hurt me, and it hurt the more because I felt that the omission was unpardonable. But the psychology at the Panchevo celebration was different from that at the conference in Belgrade. In Panchevo a remark was made from which, I was afraid, one might have inferred that this is a country of materialism. Nobody at the Belgrade conference suggested the thought that American science might, perhaps, have a taint of materialism. But, of course, no Serbian scientist could have suggested such a thing when the memory of the service of American science to Serbia during the typhus ravages of 1915 was still fresh in everybody’s mind.

A fireplace fed by slow-burning wood must be stirred up often to maintain a lively flame. Similarly, the flame of a slow mental combustion cannot be maintained without occasional stirring. My mental combustion at the Belgrade conference was certainly slow, and needed a stirring up, similar to that which it received in Panchevo. My early studies of American history and American traditions would have proceeded much more slowly, if it had not been for my old friend Bilharz, who stirred me up with his prejudices against American democracy, and with his everlasting complaints against the imaginary spectre which he called American materialism.

This stirring up is experienced by many American citizens of foreign birth whenever they visit their native land. Every one of these visits speeds up the Americanization process which is going on in them. I firmly believe that the amalgamation of the foreign-born would be speeded up wonderfully if we could make it obligatory that every foreign-born American citizen should revisit his native land at stated intervals of time. Had I not visited my native land so many times since my landing at Castle Garden in 1874, the memory of my early experiences in America, described in the earlier parts of this narrative, would probably have faded away completely long ago. Had I not visited Belgrade and Panchevo in 1919 I should not have been stirred up on the subject of American idealism, and particularly about the American idealism in science. It was in Belgrade and Panchevo where the stimulus was applied which revived the memory of my experiences in Columbia College, in the Universities of Cambridge and Berlin, and in my professorial work at Columbia University, and made me pass in rapid review through all my experiences which have a bearing upon American idealism, and particularly upon the idealism in American science. Ever since, I have been revolving in my mind many of the things relating to American science that I might have mentioned at the Belgrade conference, but did not mention. The painting, “Men of Progress,” which I first saw at Cooper Union in 1876, came back to my mind. The men represented in it, like Peter Cooper, McCormick, Goodyear, Morse, and others, did not represent the idealism in science which the Belgrade scientist had in mind; they were practical inventors. They were the scientific idols of the American people, but they were not idealists in science. The time for idealism in American science had not yet arrived. The Union Pacific Railroad had not yet been built when that picture was painted; the Western plains had not yet been compelled to yield their potential treasures of golden grain; and the vast quantities of coal and mineral ore were waiting anxiously to be raised to the surface of the earth to serve in the development of our vast territory between the Atlantic and the Pacific. He who could aid the people in this gigantic development became the idol of the people. The names of inventors, like McCormick, Goodyear, and Morse, were household words with the people of the United States, just as the names of Edison and of Bell are to-day. Joseph Henry, the famous scientist, was also in that historic painting, but he was in the background of it. His expression seemed to indicate that he did not feel quite at home in a group of men who were practical inventors. He was a friend of Lincoln, and his idealism in science was just as exalted as Lincoln’s idealism in political philosophy. But in those days an idealist in science attracted little attention among the people of the United States, who were busily engaged in solving their numerous economic problems. Hence Joseph Henry, the idealist in science, was practically unknown. This was the mental attitude which Europe called “American materialism” in science. De Tocqueville, the famous French traveller and keen observer, said this about us in a book which he published over seventy years ago:

It must be confessed that, among the civilized peoples of our age, there are few in which the highest sciences have made so little progress as in the United States.... The future will prove whether the passion for profound knowledge, so rare and so fruitful, can be born and developed so readily in democratic societies as in aristocracies.... The man of the North ... does not care for science as a pleasure, and only embraces it with avidity when it leads to useful applications.

To-day this criticism sounds like a national libel, but fifty years ago it was swallowed like a bitter pill which, in the opinion of many patriotic thinkers, we needed if we were to be cured of a malady which threatened to become a national calamity. The greatest leaders of scientific thought in this country pointed to our educational system, in order to prove that de Tocqueville was right and that science was neglected in our schools and colleges. Foremost amongst them were, as I have already pointed out in this narrative, Joseph Henry, President Barnard, of Columbia, President White, of Cornell, Draper, Youmans, and others. They were all idealists in science, and when they invited Tyndall to this country, fifty years ago, they invited the most eloquent apostle of scientific idealism. The great movement for higher scientific research, inaugurated in England by the immortal Maxwell and his supporters, and in this country by the great Joseph Henry and his followers, was a movement for idealism in science, or, as Andrew White called it, “hope for higher endeavor.”

When the European speaks of materialism in American science, he is resurrecting notions which de Tocqueville had in his mind when he wrote the lines quoted above. These notions were correct, but wonderful changes have taken place in this country since de Tocqueville wrote his book. If he were living now and published another edition of his famous book, I am sure that he would insert a chapter which would speak of idealism and not of materialism in American science.

What is the mental attitude which I call “idealism in science”? Before answering this question it is well to quote here from an earlier part of my narrative:

The _eternal truth_ was, according to my understanding at that time, the sacred background of Tyndall’s scientific faith, and the works of the great scientific discoverers, their lives, and their methods of inquiry into physical phenomena were the only sources from which the human mind can draw the light which will illuminate that sacred background. He nourished that faith with a religious devotion, and his appeals in the name of that faith were irresistible. His friends in America and in England, who were glad to have him as their advocate of the cause of scientific research, had the same faith that he had, and they nourished it with the same devotion. I know to-day ... that this faith was kindled and kept alive ... by the light of the life and of the wonderful discoveries of Michael Faraday.... He was their contemporary, and his achievements, like a great search-light, showed them the true path of scientific progress.

The worship of the eternal truth and the burning desire to seek an ever-broadening revelation of it constitute the mental attitude which I call “idealism in science.” Its growth in the British Empire, and particularly at the University of Cambridge, has been most remarkable since the great movement started under the leadership of Maxwell a little over fifty years ago. What progress have we made since Tyndall’s visit to this country in 1872? If in my narrative I succeed in answering this question I shall be more than satisfied, and I shall certainly send a translation of it in part to my scientific friends in Belgrade. It will tell them what I ought to have told them four years ago.

* * * * *

I return now to the point in my story where I digressed. The 14th of April, 1896, is recorded in my calendar as a happy day. The 15th started with a balmy spring morning full of glorious sunshine. The suggestion to walk through Central Park to Columbia College to my morning lecture could not be resisted, and I reached the lecture-room full of the joy of life which fills the heart of every healthy youth. My students told me later that the first part of my lecture that morning displayed that joy. But, near the end of the lecture, I suddenly collapsed. A sudden chill struck me like a bolt from a clear sky. Five days later my life hung in the balance; there was a desperate struggle between a stout heart and the busy poisons of dreaded pneumonia. The heart won out. But when the crisis had passed, and my physician thought that I was sufficiently strong to stand the shock of terrible news, he told me that my wife had died several days before, a victim of dreaded pneumonia. She had caught the seed of this merciless disease while nursing me. My weakened heart stood the shock, but every one of my nerves seemed to snap in two. For the first time in my life I recognized the full meaning of will-power; I recognized it because I knew that the spiritual motor, the power of which I had always felt, was there no longer. For the first time since leaving my native Idvor, twenty-six years before, I had to be steered and looked after by others. Life never looked so hopeless as it did during that awful spring of 1896. But I wanted to live, because I had a little daughter to bring up. That, in fact, was the only thing that I wanted to live for; everything else seemed either devoid of interest, or much beyond my reach. It is an awful thing to lose one’s self-reliance. Aims and aspirations appeared to me like little toy balloons that children play with; our nerves, I thought, are the strings which keep them afloat within the reach of our vision. When these strings snap in two, our aims and aspirations, like toy balloons, disappear rapidly into thin air.

My physician recommended that during that summer I should settle down in Norfolk, Connecticut, to give the bracing climate of this New England town in the Berkshire hills a chance to rebuild what overwork, under nervous tension, and pneumonia had undermined and torn down. A New York physician, who knew me through my X-ray work, offered to rent me his summer residence, facing Haystack Mountain, the highest peak in Norfolk, and I accepted it. This mountain is really only a hill, hardly one thousand feet higher than the road at its foot, but as I sat on the piazza in front of that little cottage and looked at the so-called observatory, a square frame structure on the top of this hill, from which people caught the distant view of the Housatonic valley, I wondered whether I should ever be strong enough to climb to its top. I recalled my exploits in Switzerland, thirteen years before, and, utterly discouraged by the comparison, I accepted with calm resignation that I had grown old and decrepit in less time than it takes other people to become middle-aged. Whenever I thought of my past, present, or future, I always managed to draw some gloomy conclusion of that kind, and, so far as my cloudy fancy could see, I felt that I had finished my career in dismal failure. People told me that these were queer notions due to mental depression, from which I would soon recover. But, as time went on and there was no relief, I resented it when people tried to console me with, what I considered, empty promises of a brighter future. There suddenly appeared an angel who promised nothing but gave much.

Another New York physician, the well-known Doctor Frederick Shepard Dennis, also an admirer of my X-ray work, had a summer residence at Norfolk. He was practically a native of this quaint New England town, and believed in its great virtues as a resort for convalescents. He was very anxious that my summer vacation there should put me on my feet again, but he saw that my introspective life on the lonely piazza facing Haystack Mountain blocked every road which might lead to my physical and mental restoration. “Professor,” said he one day to me, “if you do not stop thinking about yourself you will never get well.” “But,” said I, “what else is there to think about? I hate to think about that horrible green phosphorescence of vacuum tubes, about the X-rays, fluorescent screens, and skeletons of hands and feet and ribs. Those are the things which haunted incessantly my burning brain during the pneumonia fever, and I shall never think of them again if I can help it. I should like to think about some other problems which are waiting in my laboratory, but what is the use? I have no hope of living long enough to solve them, or that, if I live, I shall have the necessary brain energy to work out their solution. Besides, whenever I begin to think of something pleasant or interesting my heart suddenly gives a violent thump, and sends a cold shiver through my timid veins. I must think of myself, because I am always on my guard against something that might happen at any moment to cut the last thread of my shaky vitality. It is this everlasting fear that keeps me thinking about myself.” The good doctor looked thoughtful, but said nothing; a few days later he drove up in a little yellow runabout, drawn by a pair of cobs of beautiful dark chestnut color, which were a splendid product of his stud farm; they shone like old mahogany. “How do you like them, professor?” asked the doctor, as he scrutinized my admiring gaze. “They are a thing of beauty and a joy forever,” said I, and I meant what I said. The next day the cobs, with wagon and harness, were mine; they were only three years old, and, although broken to harness, they were quite raw and needed training. I got them after pledging my word to the doctor that I would train them. My native Banat is like Kentucky. Everybody raises horses, and everybody knows by intuition how to handle a horse. I was told by experts that I handled those cobs just right. While training them I really trained my own nerves. They needed it more than the cobs did. “Horse sense” has meant to me ever since a sense which enables man to train a horse, and that means to give up your whole heart and soul to the horse. The trainer must never think of himself, but always of his beloved animal. He must be patient and persistent, kind and affectionate, forgiving mistakes and showing full appreciation for even the smallest honest effort. Only by the exercise of these virtues can he succeed in developing in the horse the habit of being a splendid horse. Doctor Dennis was a great lover of horses, and he knew all that, and thought, as he told me later, that it was the best medicine for me.

My cobs acquired the best of habits, and at the end of a year they were two beautifully balanced animals, carrying their proud heads on high, and stepping up in perfect unison. They seemed, when in full action, to be anxious to strike their foreheads with their knees. To sit behind those animals, and watch their swaggering motion around the horse-show ring, gave a thrill never to be forgotten. The New York horse-show in Madison Square Garden, in the autumn of 1897, and the Philadelphia horse-show at Wissahickon, in the spring of 1898, established the great reputation of Comet and Princess Rose, the cobs that I had been training during eighteen months. They won many prizes, but none of them was as welcome as the prize of my restored health. I got well without knowing that I was getting well; the only improvement that I was watching and thinking about was the improvement of my beautiful cobs, but, nevertheless, my laboratory assistant Cushman noticed in the early spring of 1897 that I had already begun to speak much more encouragingly about some of my old laboratory problems; he noticed it, and he was happy again. The X-ray problems were not among them; I never recovered from the feeling of horror which the thought of them gave me during my sickness in April, 1896.

Reginald Rives, one of the social leaders of New York, was the judge at Wissahickon who awarded the prizes to my cobs. We had been in college together, but when he saw me at the horse-show he did not recognize me at first, because, as he informed me later, he did not expect to see a college professor driving high-steppers at a horse-show. He spoke very highly of my cobs, which won from a competitor like millionaire Widener’s stable in Philadelphia.

“Pupin,” exclaimed Rives, “if you can handle your students as well as you can handle your cobs, you are the greatest professor in America.” “I could,” said I, “if I had to handle only two students at a time, but not two hundred.” Rives repeated this remark to his brother, a trustee of Columbia University, and the trustee saw in it quite a chunk of educational philosophy. The preceptorial system at Princeton reminds one of this philosophy. Will the American colleges ever adopt it?

A famous Boston lover of horses, a Mr. Jordan, saw my cobs at the Wissahickon horse-show and made me a handsome bid for them in cash besides “throwing in” a very handsome Irish hunter which had won a prize in the jumping class. The hunter became my saddle-horse, and served me loyally for fully twelve years. No better saddle-horse ever cantered over the hillsides of Litchfield County than Clipper, the Irish hunter, my trusty friend and companion, particularly during my summer vacations. Thanks to Comet and Princess Rose, and to good old Clipper, and to the bracing climate of Norfolk hills, the joy of life returned again.

My first job after landing at Castle Garden was on a farm, and there I had vowed that as soon as I could afford it I would buy myself a real American farm. A little over twenty years later, in 1897, I bought a farm at Norfolk; this blessed spot, where I regained my health and happiness, became my real American home, and I have never had a desire to seek a better haven of happiness in any other place, either here or in Europe.

The native of Norfolk is a typical Connecticut Yankee. Neither the wealth nor the social position of a new summer visitor can faze him. His dignity and self-respect forbid him to kowtow to any city swell. You will get his respectful attention if you deserve it; but you must earn it by your acts at Norfolk. You cannot command it by the power of anything you bring with you from the city to your summer vacation. While you are in Norfolk in summer, you are a summer boarder, an outsider, with traditions back of you which no native of Norfolk knows anything about. The force of all this was once so strongly impressed upon me that I never forgot it.

Norfolk, like every New England town, has its annual town meetings, when the accounts of the town for the closing current year are carefully analyzed, appropriations are made for the coming year, and the selectmen and other administrative officers are elected. After I had become a landowner in Norfolk, I attended these town meetings regularly, and took part in their discussions, and there for the first time I became acquainted, by personal contact, with the fundamental elements of Anglo-Saxon civilization. At one of those town meetings I urged the improvement of the public highways, using the argument that better roads would attract more summer residents from the great cities and, I was certain, would advance the prosperity of the town. My arguments were received with respectful silence, and no sooner had I finished my speech than a Mr. Nettleton, the oldest voter in the township, got up and, turning his black goggles toward me, addressed me somewhat as follows:

“Our roads are just as good as they ever were; our ancestors taught us how to take care of them, and they are good enough for us. You say that if we improve them we would get more summer visitors, who, with their wealth, would increase the prosperity of our town. We don’t care for that kind of prosperity; it brings vanity and false pride into our New England homes, which you city people carry around with you.” Then, pointing his trembling finger at me, the old man exclaimed: “You, particularly, are guilty of this offense; you were the first who showed our simple people here how to swagger about this town on a horse with a rabbit tail.”

He referred to the almost universal custom at that time of docking a horse’s tail; the tails of my famous cobs as well as of my saddle-horse Clipper had been docked. After this speech, I suspended my propaganda for more up-to-date roads. Two years later, another incident occurred which is worth relating here. Mr. Carter, a Norfolk hunter of much local fame, had a fine pointer dog. He went to Europe one summer and left his dog in charge of a friend. But the dog ran away, and chased through all the woods of Norfolk, looking for his master. One day he came to my house; he was hungry, thirsty, tired out, and perfectly unhappy, having failed to find his master. I petted him, gave him fresh water to drink and some food to eat, and, while he was feasting, spoke to him and paid him many compliments on account of his affectionate attachment to his master. After his hearty meal he fell asleep near my feet on the piazza, and when he woke up he looked at me and seemed to be a much happier dog. From that moment on he followed me everywhere, running after my horse when I went out riding. One day I was cantering slowly along the road passing old Nettleton’s house. I saw the old man standing near the road, apparently waiting for somebody. When I was quite near him he beckoned me to stop, which I did, and he addressed me:

“Professor, I was very severe with you two years ago at that town meeting. But I did not know you; now I do. That dog there would not stay with anybody in this town, but he stays with you, and he follows you just as he followed his master. You are good to him, and the dog knows it. I have great confidence in a dog’s judgment, and I know now that you are a good man, just as good as any of the folks in this here New England town.” Then, stretching out his bony hand to me, he said: “Shake, forgive and forget, and let us be good friends. I shall never oppose you again at our annual town meetings. What’s good for you is good enough for me and for our little town.”

No offer of friendship was ever more welcome to me, and there never was a friendship of which I was more proud. Before many days had passed, the natives of Norfolk, from the illustrious Eldridge family, the angels of the town, down to the most humble day-laborer, felt the same toward me as old Nettleton did; that is, I always thought so, and I have never had any reason to think otherwise. No resolution moved by me at the annual town meetings ever failed to pass, but I always moved slowly, and not until I was quite sure that the motion was in the right direction. I would sooner have risked losing the good opinion of the trustees of Columbia University than that of the good people of Norfolk, my American Idvor. During my summer vacations in Norfolk, I have always felt just as much at home, and as happy and contented, as I did in my native Idvor when, during my student days in Europe, I spent my summer vacations there. Whenever I returned to my laboratory from my summer vacation in the bracing atmosphere of Norfolk, I have always felt that no problem there could resist the force of my stored-up nervous energy. That feeling early encouraged me in the belief that I had completely recovered from the breakdown of the spring of 1896, and this belief gave wings to every new effort.

When the news of the discovery of the Roentgen rays reached me in December of 1895, I was busy with the research of a problem which I had taken up in 1894, while making a foot tour in Switzerland. This is the problem which I took up again after the recovery from the breakdown of 1896. I must confess here that I never returned to X-ray research, because for a long time after my illness even the sight of an X-ray tube made me almost hysterical.

During the first half of the summer of 1894, Mrs. Pupin and I were staying at a little hotel on Lake Wannensee in Switzerland; I was preparing my lectures on the mathematical theory of sound. Lord Rayleigh’s treatise called my attention to the classical problem which ten years before I first saw in La Grange’s famous treatise. I had bought it second-hand in Paris, and had studied it in my mother’s garden at Idvor. The problem was a hypothetical one relating to an imaginary and not to a real physical case. It may be stated as follows:

A string without weight is stretched like a violin string between two fixed points; at equidistant intervals along this string are attached equal weights, say bird-shot. The problem is, how will this string, loaded with weights, vibrate when disturbed by an impulse? La Grange found a beautiful solution for this historic problem, and the solution marks the beginning of an epoch in the history of mathematical physics. This solution enabled him to analyze mathematically the vibrations of a violin string, one of the famous mathematical problems of the eighteenth century. I made a bold attempt to find a solution for a more general and less hypothetical form of this problem. I supposed that the string itself had weight, and that it, as well as the little weights attached to it, moved through a viscous medium. I felt intuitively what the solution should be, and considered it of much scientific importance. I finally found the most general mathematical solution of this generalized problem, and the beauty of it was that it could be stated in a very simple language. I shall state it later. The solution was exactly what I had expected it to be, and it thrilled me more than any work that I had ever done. I always believed that my training in ground-signalling which the herdsman of Idvor had taught me some twenty years before was responsible for this intuitive guess. Early impressions, particularly those relating to novel scientific facts, are very intense.

I was much encouraged by the thought that I was able to add very substantially to the solution of a historic problem first solved by famous La Grange. In order to communicate some of my joy to Mrs. Pupin, I told her that I was ready to give up mathematical reading for the rest of that summer, and we started on a drive through Switzerland. That is, she drove, while I walked a good part of the time, particularly when the carriage was moving along the zigzag roads going up to a pass, which happens often in Switzerland drives. Making short cuts, I met her every now and then on the up-grade parts of the steep and winding roads, and rode with her on the down-grade. During these walks, being alone, I pondered a great deal about my solution of the generalized La Grangian problem. One day, while climbing up to the Furka pass, it occurred to me that since the motion of electricity through a wire experiences reacting forces similar to those in the motion of the material elements in a stretched string, my generalized solution should be applicable to the motion of electricity, and I was immediately aware that I had made a very important invention. I tried to convince Mrs. Pupin of it, but she said: “I will believe what you say and will gladly congratulate you if you will promise that you will not be absent-minded during the rest of our trip.” I promised, but it was very difficult to live up to the promise. I never told her how often I longed to be back in my modest laboratory in the musty cellar under President Low’s office at Columbia College, and that too in spite of the heavenly beauty of the views which on my walks met me on every turn of the winding roads which lead up to the wonderful passes of Switzerland. I was most anxious to submit my theory to an experimental test. When our tour in Switzerland was finished I had every detail of the proposed experimental tests worked out in my head, and yet my good wife never accused me of being absent-minded. In less than a year from that time I had finished my first rough test, and was preparing for a more elaborate investigation when the discovery of the X-ray was announced, at the very end of 1895, and I, like everybody else, dropped everything and eagerly sought information about this wonderful discovery. It was the work I dropped then which I took up again after my recovery from the breakdown of 1896.

Now what is the invention which occurred to me first on my walk to the Furka pass in Switzerland in the summer of 1894? A bit of scientific history is connected with it, which I shall tell here briefly:

A vibrating motion of electricity at one end of a long wire is propagated along the wire in much the same way as the vibratory motion of a rope or string is propagated from one of its terminals to the other. This propagation of electrical motion from one end of a long conducting wire to the other was first investigated by Professor William Thomson, the late Lord Kelvin, of the University of Glasgow, in 1855, when the first Atlantic cable was projected. He worked out the problem for electrical signalling over a submarine cable, and three years later Kirchhoff, who was one of my teachers in Berlin, worked it out for telegraphic signalling over land-lines stretched over poles. When telephony was invented in 1876, there was, of course, a demand for a mathematical theory of telephonic transmission over long conducting wires. He who understood Thomson’s and Kirchhoff’s work could experience no serious difficulty in working it out. Vaschy, a Frenchman, and Heaviside, an Englishman, were the first to work it out; they did it in the chronological order just indicated, Vaschy leading Heaviside by about two years. They both observed that just as in cable and land-line telegraphy so also in telephony the reduction of the transmitted electrical force was the smaller the larger the so-called inductance of the transmitting wire. Many people believe that this observation was an important discovery; I never thought so, because I believed that Thomson’s and Kirchhoff’s work made that observation obvious. But, however that may be, the observation was made by Vaschy two years before it was made by Heaviside, and neither one nor the other saw in it a special case of a general physical principle, which the Allies appreciated much during the World War in their struggles against the submarines. I shall describe it briefly:

Sound is transmitted through water or through a solid much more efficiently than it is through air. I knew that, when, as herdsman’s assistant in Idvor, I learned the art of signalling through the ground. Now why should water or hard and heavy ground transmit sound better than air does? Idvor’s herdsman did not tell me that, but, having gained the knowledge of the fact very early, I was prepared to seize upon the dynamical explanation as soon as I needed it; and I felt the need of it in Switzerland in the summer of 1894.

Transmission of sound means transmission of vibratory motion from one element of a substance to the contiguous elements. The element which transmits its vibratory energy acts and the elements which receive it react. Each element is capable of exerting three reacting forces. One is against the change of velocity of its motion, that is, against change of momentum. This reaction is called the kinetic reaction, and, as I have pointed out before, it was discovered by Galileo three hundred years ago. The second reaction is against the elastic compression of the receiving element. It is called the elastic reaction, and was discovered by Hook, a contemporary of Newton, two hundred years ago. The third is a frictional reaction, the knowledge of which is very old. There are, therefore, three forms of energy generated in the reacting element of every vibrating body by the work of the acting element. The first reaction results in energy of motion of the mass of the reacting element; the second one results in the energy of its elastic compression; and the third one generates heat. The first and the second are energies of sound vibration and are transmitted again to the contiguous elements, but the third is not a vibratory sound energy and is not transmitted as such; it remains as heat and represents the reduction of sound energy transmitted from any one part to the contiguous parts. It is obvious that this reduction will be, relatively, the smaller the greater the first two reactions are in comparison with the frictional reaction. Heavy, incompressible bodies, like water, metals, or hard solid ground, have incomparably greater kinetic and elastic reactions than air, hence they transmit sound much better than air does. This physical principle did splendid service during the World War in submarine and subterranean detection by sound. The herdsman’s assistants in Idvor, when I was a boy, profited much from it in their signalling through the ground. I am not aware that Vaschy and Heaviside had a clear knowledge of it. If I am correct, then it is quite remarkable that Serb peasants should have been cognizant of a physical principle which was probably unknown to English and French savants, like Vaschy and Heaviside.

Passing now by analogy from motion of matter to motion of electricity, we can, speaking figuratively, state that vibratory motion of electricity will be transmitted from one end of a conducting wire to the other the more efficiently the heavier and the less compressible that electricity is, or, dropping now our figurative mode of speech, we can say that, other things being equal, the higher the kinetic and the elastic reaction of the moving electricity the more efficiently will the energy of its vibratory motion be transmitted over the wire. But that means that the inductance of the wire should be made as large and its capacity as small as possible. That much was perfectly obvious in Thomson’s and Kirchhoff’s work, some twenty years before Vaschy and Heaviside took up the mathematical theory of telephonic transmission. These two celebrated mathematicians, however, deserve much credit for their enthusiastic backing of inductance among the sceptical telephone engineers, who, at that time, knew little of the mathematical theory and of the general principle of transmission of vibratory motions.

A coil of wire wound around an iron core is the first picture in our mind when we hear inductance mentioned. Hence, if inductance increases the efficiency of transmission in a telephone transmission-line, and you cannot introduce it into the line in large amounts in any other way, then one would certainly suggest putting a lot of coils into the telephone-line and examining the results of this haphazard guess. Vaschy tried this guess, and failed. The late Mr. Pickernell, chief engineer of the long-distance department of the American Telephone and Telegraph Company, also tried it, and he also failed. It was obvious that, as Heaviside expressed it, experiment gave no encouragement with regard to inductance introduced in this way. I tried it and found that experiment offered very much encouragement to inductance introduced this way; I succeeded, because I did not guess; I was guided by the mathematical solution of the generalized La Grangian problem. What does this solution say when applied to electrical motions in a wire? It says this: Place your inductance coils into your telephone-line at such distances apart that for all vibratory motions of electricity which it is desirable to transmit there shall be several coils per wave-length. In telephonic transmission of speech that means one coil every four or five miles on overhead wires, and one coil in about every one to two miles in a telephone cable. For these wave-lengths, the wire possessing discreet lumps of inductance in the form of inductance-coils acts like a wire with uniformly distributed inductance. Such a wire transmits efficiently according to the general physical principle described above. In order to illustrate this by a mechanical analogy, we can say that a light silk cord stretched between two fixed points and carrying at equidistant points heavy bird-shot will act like a heavy uniform cord for all vibratory motions the wave-length of which embraces several intervals separating the bird-shot, and will transmit these motions much more efficiently from one end of the cord to the other than if the bird-shot were not there. This simple experiment with bird-shot and a long stretched cord can easily be tried; it is a very inexpensive experiment and will convince you even if you know nothing about the mathematical elements of the problem. This is the simple experiment which I had in my head during my tramping along the zigzag roads in Switzerland in 1894. A professor of physics, who often acted as consulting physicist to telephone companies, had such a loaded cord hung up over his lecture-room table for the purpose of explaining transmission of wave-motion from one end of the cord to the other, but he never inferred anything from it regarding loading a telephone-line with inductance-coils. When I called his attention to it, and joked about it, he blamed his hard luck, implying, I thought, that solving a dynamical problem and building upon the foundation of this solution an electrical invention is a question of luck.

From the simple apparatus, just referred to, to the elaborate electrical demonstrations which would convince stubborn and hard-headed telephone engineers, was a very long pull. The most embarrassing feature in these demonstrations was that I could not afford large expenditures of money to carry them out on actual telephone conductors; besides, it would have been unwise to disclose to interested parties, the owners of long-distance telephone-lines, a theory for which I had not yet obtained a satisfactory experimental proof. I had to invent laboratory apparatus equivalent to telephone lines or cables of great length, which would enable me to do all the experimenting in my laboratory. That required almost as much thought, inventive effort, and mathematical achievement as the solution of the extended La Grangian problem.

The first part of my research I communicated to the American Institute of Electrical Engineers in March, 1899. It dealt only with the mathematical theory of my laboratory apparatus. It spoke a great deal about La Grange, but nothing directly about the invention. In October of that year, a friend of mine, Doctor Cary T. Hutchinson, told me that he suspected that an invention was hidden in that communication. “If you have detected it, others have detected it also, and are by this time in the Patent Office,” said I. “Are you not there yourself?” asked Hutchinson, looking somewhat disturbed, and when he heard that I was not he looked discouraged. When, however, I declared my readiness to undertake to design for some clients of his a telephone cable to operate between New York and Boston, guaranteeing to employ a wire not bigger than in ordinary cables capable of operating satisfactorily over a distance of only twenty miles, Hutchinson grew quite serious, and advised me to apply for a patent before doing anything else. I finally followed his advice, and not any too soon. There were others, besides Hutchinson, who had recognized that in my communication to the American Institute of Electrical Engineers there was hidden an invention for which telephone engineers had been eagerly waiting ever since the birth of the telephone art. This created an interference in the Patent Office which annoyed me, but not nearly so much as I had been annoyed there before. About a year from the date of my application for patent, the American Telephone and Telegraph Company acquired my American patent rights, treating me most generously. It gave me what I asked; my friends thought that I had not asked enough, but to a native of Idvor a dollar looks much bigger than to a native of New York who may be a next-door neighbor to some Morgan or Rockefeller. Besides, the opinion of the highest telephone authority in the world that my solution of the extended La Grangian problem had a very important technical value was much more gratifying to me than all the money in the world.

In Europe, and particularly in England, the invention came as a surprise; they did not expect an American to make an invention which required so much mathematical analysis of electrical motions, to which the American physicist had contributed very little, whereas Vaschy and Heaviside had written volumes about it. But these writers had paid too little attention to classical writers like La Grange, Thomson, and Kirchhoff. The construction of the inductance-coil required almost as much mathematical analysis as the dynamical theory of the invention, and the method of testing it also was new to the telephone engineers. The coil is now known all over the world as the Pupin coil, and many people think that the coil itself is the invention.

When it became known that I had studied at the Universities of Cambridge and of Berlin, my English and German friends claimed the credit of the invention for the scientific training which I had received at their universities. I think the French had a better claim, because it was La Grange who helped me more than any other mathematical reading. As a matter of fact, the engineers of the American Telephone and Telegraph Company and the herdsmen of Idvor deserve most of the credit. The first formulated the problem the solution of which led to the invention, and the second taught me the art of signalling through the ground which guided me to the physical principle which underlies the invention.

A vice-president of the American Telephone and Telegraph Company, who is a very high authority in telephony, informed me recently that one way to describe, roughly, the value of the invention is as follows: If during the past twenty-two years his company had been compelled to extend its network of conductors so as to give, without employing my invention, the same service which it is giving to-day, it would have had to spend at least one hundred million dollars more than it has actually expended. But after quoting him I wish to call attention to a fact which the public often overlooks. I ask, where are those one hundred million dollars which the invention has saved? I know that not even a microscopic part of them is in the pockets of the inventor. I have figured out also, with the same accuracy with which I once figured out the invention, that those hundred million dollars are not in the pockets of the telephone company. They must be, therefore, in the pockets of the American public. The invention made it possible to give the telephone service, which is now being given, at a lower rate than would have been possible if one hundred million dollars more had been spent. Every good invention benefits the public immeasurably more than it benefits the inventor or the corporation which exploits the invention. I certainly consider myself a public benefactor, and the National Institute of Social Sciences called me so when it gave me a gold medal almost as big as the full moon. But this gift would have made me much more happy if the institute had at the same time given another gold medal to the American Telephone and Telegraph Company.

Some fifteen years ago, when Frederick P. Fish, the famous patent attorney, was the president of the American Telephone and Telegraph Company, I asked him in the course of a conversation whether he would like to sell me back my invention. “Yes,” said he, “but only if you will buy the whole telephone company with it. Our whole plant has been adjusted to the invention, and when one goes the other also must go. The invention has enabled us to detect many defects in our transmission system, and if it had done nothing else than that it would have been worth at least ten times what we paid you. It is the greatest faultfinder that we ever struck, and it is the only form of faultfinder for which we have any use.” A progressive industrial organization courts the criticism of an accurate and friendly faultfinder. It leads to research and development, and that supplies the vital energy to every industry. Twenty-five years ago the American Telephone and Telegraph Company had a small laboratory in Boston, where it did all its scientific research and development. But, presently, faultfinders like my inventions moved into the peaceful and drowsy precincts of that tiny laboratory, and stirred up the engineers and the board of directors. I am very happy whenever I think that, possibly, my inventions have contributed some to this healthful stirring up. What was the result? To-day the American Telephone and Telegraph Company and the affiliated Western Electric Company employ about three thousand persons at an expenditure of some nine million dollars annually in their research and development work. The scientific research work at our universities looks very modest in comparison with operations of this kind. Young men of the highest academic training and splendid talents are busy day and night exploring the hidden treasures on the boundary-lines between the various sciences and the science and art of telephony, and their discoveries, I am sure, are the best investment of this great industrial organization. For instance, their development of the many details in my invention have been wonderful, and give testimony of the highest kind to the excellence of their scientific research. It is not so much the occasional inventor who nurses a great art like telephony and makes it grow beyond all our expectations, as it is the intelligence of a well-organized and liberally supported research laboratory. When I think of that I am perfectly convinced that very few of the great advances in the telephone art would have happened under government ownership. That explains why telephony is practically dead in most European countries. What little life it has in Europe is due to the American research in the above-mentioned laboratories.

The General Electric Company, The Westinghouse Company, the Eastman Kodak Company, and many other industrial corporations in this country are supporting similar research and development laboratories, where scientific men of the highest training are busily exploring what Helmholtz called the rich territories near the boundary-lines of the various sciences and of the science forming the foundation of their respective industries. This reminds me of what I saw on a much smaller scale in Germany, nearly forty years ago, when I was a student there. We copied Germany’s good example, but are leading now, and the pace is so swift that Europeans are dropping behind us very rapidly. The spirit of scientific research has moved into our universities, and from the universities it has moved into our industrial organizations. Industrial research is making bigger and bigger demands upon the universities for highly trained scientific research men; the demand is larger than the supply, and because the industries can pay much higher salaries than the universities can much difficulty has been experienced in inducing bright and promising young scientists to pursue the academic career of a teacher. The quality of the scientific teacher in the university is temporarily deteriorating, that of the industrial research scientist is steadily rising; on the whole, however, the country is a gainer. The university man in the industries will transplant there the scientific idealism of the university. The captains of our leading industries already admit, as will be pointed out below, that the cultivation of scientific idealism is the best policy for our American industries. Listen to the papers which are read by their research men and you will see that the industries actually practise the new gospel of scientific idealism which they are preaching.

But I must not depart too far from the main thread of my story. When it became known that the American Telephone and Telegraph Company had acquired the rights to my _high inductance wave conductors_, all kinds of legends were told about the invention and the fabulous price paid for it. Newspapers love legends, because the public loves them. The public is a child which loves to listen to fairy-tales. The only good that this publicity did was to help me sell my inventions relating to electrical tuning and rectification in wireless telegraphy. These lay idle for quite a number of years, and waited for further developments in the wireless art before they could be employed to advantage. Electrical tuning and electrical rectification are fundamental operations in the radio art to-day, but the wireless telegraphy of the early days is a distant and poor relation of our present radio art. The world had to wait quite some time for new discoveries which gave birth to the epoch-making inventions of new men, like Lee De Forest and Major E. H. Armstrong. It had to wait also for the great industrial research laboratories before electrical tuning and rectification could come into their own. In the early days of wireless telegraphy I suggested several novel developments which might give a fair chance to tuning and rectification, but I attracted scarcely any attention. The legends just mentioned made people a little more attentive.

One morning a man stepped suddenly into my office at Columbia, and introduced himself as Mr. Green, organizer and promoter of the Marconi Company of America. He was full of action and looked like business. “Are your wireless inventions for sale?” asked Mr. Green, without much preliminary talk. “They are,” I answered, and I felt that my heart was quivering on account of the unexpected blow which this laconic question had given it. “How much?” asked Mr. Green. I gave him the first figure that came into my head, and he, not a bit daunted, asked whether I would take one-half in cash and one-half in stock. I asked him twenty-four hours to decide. “All right,” said he, and promised to call again the next day at the same hour. I should have been perfectly satisfied to accept the cash offer and close the deal even without the stock, but I was afraid that any over-anxiety on my part might scare him away. The next day he called and the deal was closed, he making a certain cash payment immediately and I agreeing to furnish certain documents before the final payment was made. I was fairly well acquainted with trading transactions in my native land; my father often took me to market-places where he bought and sold cattle and horses. I remember well the never-ending bartering which very often ended in a fizzle. The nearer you get to Constantinople the worse becomes the custom of this Oriental method of trading. Mr. Green had none of that Orientalism, and his utter indifference to the figures involved in the deal astonished me. He also took it for granted that I could and would perform all the fine things which I promised to perform; that was very flattering to me, but I was too much of an Oriental to accept, without some apprehension, his apparently implicit trust in me.

This reminds me of an incident which happened eight years ago. The Serbian Government cabled me to make a contract for five thousand tons of lard; I was its only diplomatic and consular representative in America during the war. I called up the representatives of Swift and of Armour and told them over the telephone what was wanted, requesting them to file their bids in forty-eight hours. Two days later I met them in my office and some Serbian war commissioners happened to be present. The contract was closed in less than thirty minutes, and when I told the commissioners that it involved one million dollars they crossed themselves in utter amazement. In Belgrade, they assured me, the closing of such a contract would have required at least a month. I astonished them as much as Mr. Green had astonished me, and the lard transaction reminded me strongly of my deal with the Marconi Company of America. Of course, lard handled by Swifts or Armours is a much simpler proposition than a lot of belated inventions relating to electrical tuning and electrical rectification for which there was not yet a crying demand.

A few months after my deal with Green I was in Berlin, by invitation, for the purpose of negotiating, for my telephone invention, a business agreement with the famous electrical firm of Siemens and Halske. It was founded by Werner von Siemens, whom I had met fifteen years before through the kind introduction of my teacher, Excellenz von Helmholtz. During the negotiations which lasted one month I met the directors of this corporation in almost daily conferences, which lasted never less than an hour and very often several hours. Every detail of my invention was thoroughly discussed both from the purely scientific and from the engineering side, in its relation to the earlier publications which had a bearing upon it, in its legal aspects as determined by the German patent laws; and finally the financial side was carefully considered and definitely settled. There was no bartering of any kind, neither was anything taken for granted. Contrary to our American custom, the negotiations were directly between the inventor and the scientific experts. The lawyers had very little to say, and spoke only when the experts needed and asked for their opinion. When I recall my negotiations with the American Telephone and Telegraph Company, I remember nothing but lawyers. The negotiations with Siemens and Halske recall scientific experts only; the negotiations with the Marconi Company of America recall only Green. At the close of the Berlin conferences and negotiations I was perfectly certain that I had accomplished something; I understood my invention better than I had ever understood it before, and I was perfectly certain that the scientists of Siemens and Halske understood it just as well. Their popular descriptions of it were better than anything I had ever done myself. They also gave it a new name, and called telephone conductors employing the invention “_pupinizierte linien_.” The French followed suit, and called them “_les lignes pupinizé_.” These two new words coined in my honor will last as long as the invention lasts, and so far there is no sign that it will be superseded soon by some other invention. Its simplicity and effectiveness give it much vitality.

After the completion of my negotiations in Berlin, the Siemens and Halske engineers took me to Vienna for the purpose of introducing me to the high officers in the Austrian Imperial Cabinet who guided the destinies of the telephone system of the Austrian Empire. They were glad, they said, to meet a native of Banat, a former subject of Austria, who had made so important an invention, and they assured me that their policy with regard to it would be guided entirely by the decision of the Berlin experts. Vienna did not seem to have a mind of its own, and all its thinking apparently was done for it by the experts in Berlin. I was quite elated by the idea that the Berlin experts who did the thinking for the Austrian Empire had been most happy to spend a whole month with me in daily conferences, eager to learn all they could from me. I could not help exclaiming: “Oh, what a fortunate thing it was that in my early youth I ran away from this moribund Empire, and landed in a country of opportunities, where every individual thinks through his own head and carries his load on his own back.” Germany, at that time, was so vigorous that she did not hesitate to do all the thinking and hustling for Austria as well as for Turkey, and did not realize that she was carrying around two corpses which could not be revived by even the combined vitality of all the young and vigorous nations, like the United States of America and United Germany.

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.

In October, 1899, Rowland delivered his presidential address before the society at whose head he stood. I can see now how happy he looked on that memorable occasion. Inspired by the latest revelations in Electron Physics, he prophesied what new revelations the physicists should expect in the approaching future. After describing physics as “a science above all sciences, which deals with the foundation of the universe, with the constitution of matter from which everything in the universe is made, and with the ether of space by which alone the various portions of matter forming the universe affect each other ...” he stated frankly that the physicists of America “form an aristocracy, not of wealth, not of pedigree, but of intellect and ideals.... Let us cultivate the idea of the dignity of our pursuit so that this feeling may sustain us in the midst of a world which gives its highest praise, not to the investigator in the pure ethereal physics which our society is formed to cultivate, but to the one who uses it for satisfying the physical rather than the intellectual needs of mankind.” He then pleaded that we “recognize the eras when great thoughts have been introduced into our subject and honor the great men who introduced them and proved them correct.” Then, enumerating the great problems of the physical universe, he asked: “What is matter; what is gravitation; what is ether and radiation; what is electricity and magnetism; how are these connected together, and what is their relation to heat?” Now, these are the very questions which Electron Physics has been trying to answer since that time; and this is the idealism which the American physicist has had before him ever since the days of Rowland.

Electromagnetic theory of matter was the first answer to Rowland’s question: What is matter? But how about the answer to his second question: What is gravitation? If matter contains nothing but electrons, if they are really the most fundamental building stones of matter, then electricity as concentrated and stored up in the electrons can exert in addition to the well-known electrical force also a gravitational force. A somewhat novel idea, but ... why not, and why so? Einstein gives the best answer to this.

To Rowland’s question: What is Ether? Electron Physics gave a puzzling answer, but the puzzle has led us into a side path of surpassing beauty. Our famous physicists, Michelson and Morley, are a combination of two names better known in the world of physical science to-day than Castor and Pollux were known when Zeus, descending from the heights of Mount Olympus, sought the companionship of mortal men. The fame of the twins, Michelson and Morley, not, however, of Michelson alone, rests upon an experimental demonstration, the importance of which was not until recently fully appreciated, the demonstration, namely, that there is no ether drift; that is to say, so far as man can tell, there is no relative motion between the earth moving through space and the ether which is supposed to fill all interstellar space. On the other hand, the hypothesis that the ether moves with the moving earth leads to insurmountable difficulties. This was, indeed, a most embarrassing situation! Since Michelson originally, and, later, Michelson and Morley, employed the radiation of light in their attempts to detect the ether drift, it became necessary to re-examine the electromagnetic theory of propagation of light for the case that light, as in the Michelson and Morley experiment, proceeds from a source which together with the observer is moving through space. The famous Professor Lorentz, of Leyden, Holland, whom I have the honor of knowing personally, made the first successful extension of this theory, and explained satisfactorily Michelson and Morley’s result. But the extension was obtained by what was acknowledged to be a clever notion, and not by an unavoidable physical fact. The same extension of the theory was obtained by Einstein, but it was founded upon a broad physical principle which Lorentz’s extension lacked. Lorentz preferred Einstein’s deduction of his extension, called the Lorentz transformation. The physical principle just referred to is now popularly known as the Special Relativity Theory, which Einstein extended later into the General Relativity Theory. Einstein’s theory explains very simply the Michelson-Morley experiment, but how does it answer Rowland’s question: What is Ether? Also very simply by saying that ether is superfluous in our analysis of physical phenomena. Faraday expressed a similar view nearly eighty years ago. That, however, which is essential in this narrative in connection with Einstein’s relativity theory is the great fact that by it a general demonstration is furnished that all forms of electrical energy are a mass which has _inertial as well as gravitational_ activity. In the electromagnetic theory of matter this demonstration plays a most important part. One of the schemes of this theory is so simple and so beautiful, and appeals so strongly even to an imagination not scientifically trained, that I must tell here very briefly some of its most striking features.

All atoms are built up from a single atom, the atom of hydrogen, which consists of a positive electron or proton, the nucleus, and a single negative electron revolving around it like a satellite around the central planet. A heavier atom, say an atom of oxygen, consists of sixteen atoms of hydrogen, the positive nuclei of which form the positive nucleus or central portion of the oxygen atom. Some of the negative electrons are distributed among the positive electrons of the central nucleus, serving to cement them together, and the other negative electrons are revolving like satellites around the central nucleus. The number of these satellites is the atomic number of the atom, and it is this number, and not the atomic weight, which determines the chemical characteristics of the atoms. This is only a mere glance into the structure of Electron Physics, made here for the purpose of pointing out some of the never-dreamt-of possibilities that Electron Physics holds in view. For instance, four atoms of hydrogen combining into an atom of helium give off a certain amount of energy. We say the atoms of hydrogen degrade into the heavier atom of helium and, thereby, a certain amount of energy is liberated. A helium atom weighs less than four atoms of hydrogen, because of the diminished energy per atom of hydrogen, the decrement of the weight being proportional to the decrement of energy. This is demanded by Einstein’s theory, which is really an extension of the theory first proposed by Sir John Joseph Thomson, and it is a remarkable fact that these weight relations satisfy the prophecy of the theory. The amount of energy obtained by the degradation of the lighter into heavier atoms is enormous. But we do not know how to produce the process of this degradation. The question arises: Do not the young stars, the very hot stars, which always consist of gases of small atomic weight, obtain a supply of radiant energy from the degradation of atoms of small into atoms of high atomic weight, and, if this is so, then why shall we not some day learn this great secret from the stars? The language of the stars has many deep secrets to tell; it mystifies me just as much to-day as it did on the pasturelands of my native village fifty years ago.

Many other most startling contemplations may be connected with the new views opened up by Electron Physics, all of them illustrating the beauty, the wealth, and the power of a new science which represents the marriage of two great sciences, physics and chemistry.

Industrial science is very much impressed by new discoveries which, as Rowland expressed it, “deal with the foundation of the universe,” but which in spite of their revolutionary character are easily understood by the practical man. Electron Physics abounds in discoveries of that kind, and it seems that they have rushed upon us like a cloud-burst. Things have been done that formerly seemed impossible. Take, for an illustration, a thing which is so familiar to all, the complete transformation of wireless telegraphy into the new art which is called Radio. A vacuum-tube with a hot filament fills up with negative electrons, which are thrown off by the hot filament. The filament may be said to be radioactive. A current can be established by applying an electromotive force which drives these negative electrons from the space surrounding the hot filament to a positive electrode. Here we have a new type of Crookes’s tube, operated by a small electrical tension, and not by that of a powerful induction-coil, which is necessary when the negative electrode is cold. This current is called the thermionic current, and its value can be varied in any way we please by a second electrical force which acts through a third electrode, called the grid, placed in the path of the thermionic current. This is the so-called audion tube, invented by a Yale graduate, Doctor Lee De Forest. In the hands of the Western Electric Company and of the General Electric Company, this tube has transformed the whole radio art by its amplifying power. My old inventions of electrical tuning and rectification have been raised to unexpected powers by the action of these tubes, and the inventions of my former pupil and research associate, Major E. H. Armstrong, and of others, have given us the broadcasting art, which surpasses the wildest expectations of even the rosiest of optimists of a few years ago. Wherever Electron Physics has entered there have sprung up new crops of the rarest fruit, and it is no wonder that there are to-day so many workers in the newly discovered fertile fields of the electromagnetic theory. Attend any meeting of the American Physical Society and you will be convinced that the research in the university laboratories as well as in the research laboratories of our industries would satisfy even the highest expectations of the men who fifty years ago, under the leadership of Joseph Henry, started the movement in favor of higher scientific research. The university and the industrial laboratories are mindful of Rowland’s admonition: “In choosing subjects for our investigation, let us, if possible, work upon those subjects which will finally give us advanced knowledge of some great subject.” What subject can be greater than eternal truth, and that aim, according to my definition, is idealism in science.

It is very true that our American scientific research activities in physics and chemistry are so alive to-day because they have been greatly stimulated by the wonderful advances, through electron physics, in the electromagnetic theory, and in its very successful applications to technical and industrial problems. But it is also true that the scientific research activities in other branches, like biology, which are not closely connected with the electromagnetic theory and its applications, have also blossomed up with wonderful rapidity during the last twenty-five years. It will be conceded, I think, that all these activities in abstract science are to a very substantial extent due to the rapid rise of the American university and to its splendid influence upon the mentality of our industries. But in this democratic country, covering a vast area, each State has the privilege of regulating in its own way its own educational programme and policy, and each privately endowed university can pursue its own ideals in its own way without worrying very much about any other university. Lack of unity and uniformity was, therefore, always felt, and there was always a strong although often an unconscious desire in the hearts of scientific men to bring about a uniformity in the aims and aspirations of higher scientific research in our universities. The American Association for the Advancement of Science made quite a number of efforts in this direction, but the progress was slow. The great World War forced us to make another big effort in this direction, and this time the effort succeeded beyond all expectations. The following story of this big effort is, I am sure, of national importance, and should be known by every intelligent person in the United States.

Just as the cultivation of science in the United States was first taken up in the technical schools, like the School of Mines of Columbia College, the Massachusetts Institute of Technology, and many others, and not in colleges or universities, so the organization of scientific associations took place first among the engineers, the graduates of the technical schools. The American Society of Civil Engineers, the American Institute of Mining and Metallurgical Engineers, the American Society of Mechanical Engineers, and the American Institute of Electrical Engineers, for instance, were organized some time before most of the present associations in abstract science, that is in mathematics, physics, chemistry, and biology were organized. Even the youngest among the leading engineering societies, that is, the American Institute of Electrical Engineers, was organized in the early eighties, whereas the American Physical Society was organized nearly twenty years later, in 1899.

The organization of these technical societies did not wait for the arrival of the American university. But, nevertheless, when the American university arrived, and with it the research laboratories in the fundamental sciences, it improved the quality of the American engineer, and of the American engineering societies, just as it improved the scientific standards of the American industrial organizations. The National Academy of Sciences deserves here a special consideration. It is an association of workers in _abstract science_, principally, but, contrary to what I have just said, it is, like the American Philosophical Society, founded by Franklin, older than any of our national engineering societies. Its early birth was due to the conditions created by the Civil War. Joseph Henry, I imagine, suggested to President Lincoln that a mobilization of the scientific resources of the North would improve greatly its military strength, and thus the National Academy of Sciences was chartered by Congress during the Civil War, in 1863, and was approved by President Lincoln. It was a creation of the Civil War, and is in many respects an institution which forms a part of the Federal Government. I shall describe now how the National Academy of Sciences, itself a creation of the Federal Government during the Civil War, gave birth during the World War to another national scientific institution which is the climax of the great scientific movement started fifty years ago. I have watched this movement almost from its very beginning up to the present time; yes, I have been a part of it during its most active period, and I believe that I understand its full meaning.

The four leading engineering societies, mentioned above, were in quite a flourishing condition at the beginning of this century; flourishing not only with regard to the number, but also with regard to the quality of their membership, and their progress was speeding on with remarkable rapidity. For instance, the papers read before the American Institute of Electrical Engineers in 1900, and the discussions which followed them, were immeasurably superior to those read in 1890, when I first became a member of this Institute, because the quality of its membership was also immeasurably superior. The great American industries paid much more respectful attention to these engineering societies than when I first came to Columbia College in 1889. The greatest among the American captains of industry of those days, the late Andrew Carnegie, held them in so high an esteem that he presented a magnificent gift to them which led to the formation of the United Engineering Society. This happened in 1904, and marks one of the great events in the history of American technical science.

It is of considerable historical interest to observe here that Carnegie’s magnificent gift to these national engineering societies is closely connected with a very modest move made by the American Institute of Electrical Engineers, nearly thirty years ago. The late Doctor Schuyler Skaats Wheeler, at one time president of the American Institute of Electrical Engineers, had purchased the famous electrical library of the late Latimer Clark, of London, and had presented it to the Institute. But the Institute had no building of its own, and, therefore, no place for housing permanently this unique library. Several of the members of the Institute, including myself, were looking around anxiously for some practical scheme which would provide the Institute with a home of its own, where the Latimer Clark library could be permanently located. It was obvious that Andrew Carnegie, who was always interested in libraries, should be selected as our first point of application. We never had to appeal to anybody else; Mr. Carnegie was most generous. The engineering societies appealed to his lively imagination. It was the engineer who assisted him in the development of the great steel industry, and it was the engineer upon whom he relied to maintain the American steel industry in the leading position which it had won, in a great measure, by Carnegie’s initiative and efforts. He had already paid a splendid tribute to science for the service it had rendered to him when he created and richly endowed the Carnegie Institution of Washington, which was to provide and does provide ample facilities to American genius in its efforts to solve some of the great problems in science. I mention here as an illustration the endowment of the Mount Wilson Astrophysical Observatory at Pasadena, California, an act which has borne magnificent fruit under Professor George Ellery Hale’s direction. Instead of giving to the American Institute of Electrical Engineers a building for a library, Mr. Carnegie presented to the four national engineering societies a building for their permanent home, with suitable accommodations for a great library, for administrative offices, for conference and meeting rooms, for lecture-rooms, and for a great assembly hall. One of the objects of the United Engineering Society was, according to its charter, to hold and administer this princely gift “for the purpose of advancing the engineering arts and sciences in all their branches and for maintaining a free public engineering library.” The famous Latimer Clark electrical library is now a part of this great engineering library. The four national societies represented by the United Engineering Society have a carefully picked membership of over fifty thousand, and the magnificence of their home on Thirty-ninth Street, near Fifth Avenue, New York, is fully justified by their great prestige. I never look upon this beautiful structure without being thrilled by the thought that the treasures it contains in the form of organized scientific achievement and brains are among the greatest of the many rich assets of this nation.

Sixteen years ago, Mr. Carnegie and myself represented the American Philosophical Society at the memorial service for the late Lord Kelvin, the famous scientist. It was held in the great hall of the Engineering Building. As we sat on the platform, waiting for the commencement of the ceremony, I scanned the beautiful proportions of the great hall, and they appeared to me more beautiful than ever. “You must feel very happy when you look at this splendid gift which you made to the Engineering Society,” said I to Mr. Carnegie, who sat on my right. “I do, yes indeed I do, and I hope that some day you may experience the same feeling of happiness which comes from giving,” responded the great ironmaster. “Perhaps I will,” said I, “but remember that I am a Serb, and not a Scot: it takes a Scot to understand and to practise the art of giving.” “But it also takes a Scot to understand and to practise the art of taking,” said Mr. Carnegie, and his vigorous eyes sparkled with the light of good-natured humor.

Another event occurred in the history of the four founder societies which will always mark the beginning of a new epoch in American science. Another captain of American industry extended a generous hand to the United Engineering Society, offering to aid it in its work of “advancing the engineering arts and sciences in all their branches.” It is very significant that this second generous captain of industry was in many respects a striking contrast to the first, the late Andrew Carnegie. I am speaking now of Ambrose Swasey of Cleveland, Ohio. He, like Carnegie, started his industrial career with very small training in technical sciences. What he knew about engineering and manufacturing he had obtained by practical experience. Ambrose Swasey is a splendid illustration of a disciplined intellect trained by the training of his hand. I have always believed that the most striking difference between the American and the European is due to the fact that the American in his early youth receives a much better manual training than the European does, and that this accounts for the American directness of thought, judgment, and action. I never saw a better illustration of this theory than Mr. Ambrose Swasey. He began his career as a machinist, and when a little over thirty years of age he and a friend of his, Mr. Warner, another young machinist, started a manufacturing plant of their own, making fine machine-tools and astronomical instruments of precision. The shops of Warner and Swasey became famous all over the world for their wonderful workmanship.

The American manufacturer has achieved great things in mass production. This was Mr. Carnegie’s strong point; but Mr. Swasey did not belong to that type of American manufacturer. His aim was few products but each one of them as perfect as careful manipulation, personal attention guided by superior intelligence, and inventive ingenuity, could make it. Most of the telescope mountings of the great astronomical observatories in this country were made in Mr. Swasey’s Cleveland shops. His shop experience made him an engineer of a very high order, so high indeed, that the American Society of Mechanical Engineers elected him president, and, later, honorary member. The charter of the United Engineering Society speaks of “advancing the engineering arts and sciences in all their branches,” but there was no other visible instrumentality for doing that work than the free engineering library. Ambrose Swasey proposed to correct this deficiency when, in 1914, he offered to the United Engineering Society a gift of two hundred thousand dollars as a nucleus for an endowment the income of which was to be used for “the furtherance of research in science and engineering, or for the advancement in any other manner of the profession of engineering and the good of mankind.” These words, dictated by an American captain of industry, bear witness to the fact that there is much idealism in American industry. The United Engineering Society accepted Mr. Swasey’s gift, and established the Engineering Foundation, which was managed by its own board, the Foundation Board, nominated by the four founder societies. Its members acted as trustees of Mr. Swasey’s gift and of any other gift that might be given to the Engineering Foundation to serve a purpose similar to that of Mr. Swasey’s gift. This Foundation became an instrumentality of the United Engineering Society for the stimulation, direction, and support of scientific research. It became, furthermore, the liaison agency between the engineers on the one hand and the technologists and scientists on the other hand, in activities concerned with research in all branches of mathematical, physical, and biological sciences. In other words, one of the great captains of American industry, Andrew Carnegie, was instrumental in bringing the great national engineering societies together into the United Engineering Society, and another great captain of American industry, Ambrose Swasey, invented and by his generosity constructed an instrumentality, the Engineering Foundation, which he put into the hands of the United Engineering Society for the purpose of enabling it to do the work which its charter demands, “advancing the engineering arts and sciences in all their branches.” I never think of these two generous acts on the part of Mr. Carnegie and of Mr. Swasey, without being reminded that these two great organizers of American industry were guided by the same motives of idealism which had guided the great men of the revolutionary times when they organized the United States. Read the charters of the Carnegie Institution, of the Engineering Society, and of the Engineering Foundation, and you will find that no trace of materialism can be found in the proposed scientific activities of these institutions founded by two men who made material things but never lost touch with the spiritual world which gave direction and discipline to all their acts.

The Engineering Foundation became an operating instrumentality in April, 1915, and in a year from that time it was called upon to engage in a scientific enterprise which, in my opinion, has proved to be of the very greatest national importance. In April, 1916, it appeared that we were to become involved in the World War on account of the sinking of the _Sussex_ by German submarines. The charter of the National Academy of Sciences, passed by Congress and approved by President Lincoln in 1863, provides that “the Academy shall, whenever called upon by any department of the Government, investigate, examine, experiment, and report upon any subject of science and art.” The early records indicate that during its very earliest days the National Academy of Sciences, under the leadership of Joseph Henry, and while the Civil War was still going on, dealt actively with scientific research relating to military and naval problems. It was, therefore, perfectly natural that, in view of the threatening crisis, the National Academy of Sciences should, in April, 1916, offer its services to the President of the United States, who accepted them and requested the Academy to organize the scientific and technical resources of the country in the broadest and most effective manner. This is how the _National Research Council_ was born. It is the offspring of the National Academy of Sciences. The mother was born during the Civil War, and the offspring was born during the World War. Blessed be the country which even in times of war creates institutions the highest aim of which is to cultivate the arts of peace!

The members of the National Academy of Sciences are elected on account of distinguished services to science, and not on account of their cleverness as administrators or organizers. The National Research Council was to be organized for the purpose of “stimulating research in mathematical, physical, and biological sciences, and in the application of these sciences to engineering, agriculture, medicine, and other useful arts, with the object of increasing knowledge, of strengthening the national defense, and of contributing in other ways to the public welfare.” The words just quoted are taken from President Wilson’s executive order, and describe a splendid conception. But from conception to reduction to practice is a long pull, requiring efforts along most practical lines of endeavor in which scientific men as a rule do not excel. But it was very fortunate for the National Academy of Sciences and for the people of the United States that among the scientists of the Academy there was one man who had always displayed just as remarkable a genius for organization as he had for original scientific research; I mean Professor George Ellery Hale, director of the Mount Wilson Observatory. Several other members of the Academy, including myself, did our best to aid him in the task of reducing to practice many of his ideas relating to the National Research Council. There was, fortunately, one thing which greatly assisted our earliest and most difficult efforts in behalf of this national movement; it was the existence of the Engineering Foundation.

My former pupil, Gano Dunn, was in 1916 the chairman of the Engineering Foundation, and I was one of the two vice-chairmen. It did not cost me much effort to persuade Dunn that one of the biggest tasks which the Engineering Foundation could take up was to grubstake the National Research Council during its formative period. The Board of the Foundation accepted enthusiastically this suggestion, recommended by Mr. Dunn and myself, and from September 1916 to September 1917 the administrative organization as well as the total income of the Foundation was devoted to the organizing work of the National Research Council. I am very proud that during a part of that period I was the chairman of the Engineering Foundation, succeeding Mr. Dunn, and had splendid opportunities to aid Professor Hale and his committees in the historic work of organizing the National Research Council. Mr. Swasey was very happy in this national work of the Foundation, and he added to its income for that year a sum of five thousand dollars as additional aid for its great undertaking. At the expiration of that year, the National Research Council did not need any further financial assistance from the Engineering Foundation, but the co-operation started in 1916 between the two national bodies continued and produced splendid results; so much so that in 1918, during my term of office as chairman of the Foundation, Mr. Swasey added one hundred thousand dollars to his original gift, and in 1920 two hundred thousand dollars more, and the Engineering Foundation became the guiding and controlling factor in the activities of the engineering division of the National Research Council. Mr. Swasey always hoped that others would follow his example and by their generous contribution increase the income of the Engineering Foundation to what it should be. This institution, as the directing instrument of the engineering division of the National Research Council, could, with an adequate annual income, say one hundred thousand dollars or more, do a world of good in the research of our great national engineering problems. I trust that Mr. Swasey’s hopes will not meet with disappointment, because his hopes are based upon his accurate estimate of what the engineering profession needs. An estimate supported by the judgment and vision of a Swasey, and by his generous financial efforts, should receive the most respectful attention and warmest sympathy of our public-spirited men.

It goes without saying that during the World War the National Research Council was organized mainly with a view to aiding the government in the pursuit of the war, and for that purpose it was closely associated with the government’s scientific bureaus, and with the technical department of the Army and Navy. This arrangement is referred to, and receives the highest official sanction, in the executive order issued by President Wilson, which I quote now in full:

EXECUTIVE ORDER ISSUED BY THE PRESIDENT OF THE UNITED STATES

The National Research Council was organized in 1916 at the request of the President by the National Academy of Sciences, under its Congressional charter, as a measure of national preparedness. The work accomplished by the Council in organizing research and in securing co-operation of military and civilian agencies in the solution of military problems demonstrates its capacity for larger service. The National Academy of Sciences is therefore requested to perpetuate the National Research Council, the duties of which shall be as follows:

1. In general, to stimulate research in the mathematical, physical, and biological sciences, and in the application of these sciences to engineering, agriculture, medicine, and other useful arts, with the object of increasing knowledge, of strengthening the national defense, and of contributing in other ways to the public welfare.

2. To survey the larger possibilities of science, to formulate comprehensive projects of research, and to develop effective means of utilizing the scientific and technical resources of the country for dealing with these projects.

3. To promote co-operation in research, at home and abroad, in order to secure concentration of effort, minimize duplication, and stimulate progress; but in all co-operative undertakings to give encouragement to individual initiative, as fundamentally important to the advancement of science.

4. To serve as a means of bringing American and foreign investigators into active co-operation with the scientific and technical services of the War and Navy Departments and with those of the civil branches of the Government.

5. To direct the attention of scientific and technical investigators to the present importance of military and industrial problems in connection with the war, and to aid in the solution of these problems by organizing specific researches.

6. To gather and collate scientific and technical information at home and abroad, in co-operation with governmental and other agencies and to render such information available to duly accredited persons.

Effective prosecution of the Council’s work requires the cordial collaboration of the scientific and technical branches of the Government, both military and civil. To this end representatives of the Government, upon the nomination of the National Academy of Sciences, will be designated by the President as members of the Council, as heretofore, and the heads of the departments immediately concerned will continue to co-operate in every way that may be required.

(Signed) WOODROW WILSON. The White House, May 11, 1918.

During the World War the National Research Council was only partly supported by the government, although it did exclusively government work. After the war, however, the activities of the National Research Council were reorganized without departing from the spirit of the President’s executive order, and its support was derived from private sources only. Its organization can be described broadly as follows:

It consists of two groups of divisions; one group comprises seven divisions of science and technology, representing, respectively, physics, mathematics, and astronomy; chemistry and chemical technology; biology and agriculture; the medical sciences; psychology and anthropology; geology and geography; and, finally, one of the largest and most important of its divisions, the division of engineering. The other group comprises six divisions of general relations, representing foreign relations, government relations, state relations, educational relations, research extension, and research information. In this scheme of organization the National Research Council enjoys the active co-operation of about seventy-five major scientific and technical societies of the country. It is, therefore, national in its character. It promises to become one of the most precious assets of this nation, and the nation should know much more about it than it does.

The splendid work done by the Council even during the first two years of its history attracted much attention from the best men in the country, with the result that the trustees of the Carnegie Corporation of New York made a gift of five million dollars to the Council. A part of this, a little over one-quarter, was to be spent on an administrative building, the future home of the Academy and of its offspring, the National Research Council. The remainder was to be a permanent foundation from the income of which the administrative work of the Council was to be and is now being supported.

The Rockefeller Foundation and the Rockefeller General Education Board gave the Council one million dollars for the maintenance, during five years, of research fellowships in physics and chemistry, and in medicine. Other gifts came from philanthropic organizations, individual concerns, and individuals, for the support of special scientific projects, and more than a score of individuals interested in the promotion of science contributed two hundred thousand dollars for the purchase of land in Washington on which the administration building of the Academy and Council has been under construction during the last two years.

Facing the Mall near the Lincoln memorial in Washington stands to-day, nearly completed, the administrative palace of the National Academy of Sciences and of its offspring, the National Research Council. The classical simplicity of its design and its snowy marble make it appear at a distance like a Grecian temple. It will always invite the visitor to the nation’s capital to its peaceful precincts, whence one can get the impressive view of the beautiful monument to great Lincoln and of the Arlington heights on the distant bank of the Potomac River. When Lincoln and those buried on these sacred heights died, the National Academy of Sciences was born. The lives of these dead heroes of sixty years ago, as well as the life of the institution born then and living to-day, will always remind us that national defense is a stern reality and the most sacred of our patriotic duties. National defense is and always should be the uppermost idea in the history of the National Research Council, but national defense in its broadest sense, that is, defense by powder and sword and scientific invention when a brutal enemy attacks us, and by the stored-up accomplishments of scientifically trained intellects and disciplined spirits whenever this nation engages in peaceful competitions with other nations.

The rapid rise of the Council into public favor is due principally to its wise programme and to the standing of the men and of the scientific organizations engaged in the carrying out of that programme, the fundamental feature of which is “to promote scientific research and the application and dissemination of scientific knowledge for the benefit of our national strength and well-being.” This expression, often heard within the ranks of the National Research Council, always reminds me of the following words in Washington’s Farewell Address:

Promote, then, as an object of primary importance, institutions for the general diffusion of knowledge. In proportion as the structure of a government gives force to public opinion, it is essential that public opinion should be enlightened.

In no branch of human activity does public opinion need enlightenment so much as it does in the fundamentals of science, and in their relation to technical arts. One weak point in every democracy, particularly when poorly understood and practised, is the belief among those who control political patronage that any man can do any job as well as any other man. The scientific man believes that a man must be trained for the job; hence his profound respect for the expert. Nothing in his opinion will advance our national strength and well-being so much as the ability of enlightened public opinion to differentiate between the expert and the clumsy product of political patronage. A motto of the Allies in the World War was: make the world safe for democracy. But those who are to-day associated in the National Research Council believe that it is even more important to “make democracy safe for the world” by the dissemination of scientific knowledge for the benefit of national strength and well-being. Many of us believe that this is the most important part of the national defense, to which the Council will always be pledged.

The National Research Council is not an organization which operates scientific laboratories; it confines its attention to the stimulation of co-operation between scientific workers, where such co-operation is necessary. This is not the place to discuss in detail all the aims and aspirations of the National Research Council and of the instrumentalities which it has created in order to reach these aims. A survey, even a brief one, of the work of the divisions belonging to the two groups of the National Research Council will give some idea of these aims. There are, however, two great aims which should be mentioned here, which have been well expressed by Doctor Vernon Kellogg, Permanent Secretary of the Council and chairman of its division on Educational Relations. He describes one of them as follows: “It [the National Research Council] will try constantly to encourage the interest of universities and colleges in research and in the training of research workers, so that the inspiration and fitting of American youth for scientific work may never fall so low as to threaten to interrupt the constantly needed output of well-trained and devoted scientific talent in the land.” The other principal aim he describes in the following significant words: “Still another [assistance to science] is the stimulation of larger industrial organizations, which may be in the situation to maintain their own independent laboratories, to see the advantage of contributing to the support of pure science in the universities and research institutes, for the sake of increasing the scientific knowledge and scientific personnel upon which future progress in applied science absolutely depends.”

The appeal of the National Research Council to the American universities and colleges in behalf of scientific research will not be like a voice in the wilderness. There never was so much enthusiasm for scientific research in the American colleges and universities as there is to-day. This enthusiasm will continually increase as time goes on, because many of the scientific workers in these institutions are gradually catching that enthusiasm during their term of office as members of the divisions of the National Research Council. Before very long most of these workers will have served as such members, because the election to membership is for a short term only, so that every scientist in the land who wishes to serve will get a chance to serve, and in this manner will become familiar with the aims and aspirations of the National Research Council. This rotational term of membership in the divisions of the Council is a splendid method of carrying on the educational propaganda, particularly among the younger scientists of the United States. Before very long the scientists associated by service in the Council will be like the soldiers of a great army of volunteers, each one of them believing in and ready to struggle for the same ideals, and all of them controlled by the same _esprit de corps_, which the world will soon recognize as the _esprit de corps_ of American science.

With regard to the Council’s second principal aim, described so well by Doctor Kellogg, I am happy to make the following comment: A distinguished lawyer, chairman of the board of directors of a large industrial corporation, which maintains a splendid industrial research laboratory, said in my presence recently that he thought every successful and prosperous industrial organization should set aside a goodly portion of its profits from new developments, made possible by scientific research, and turn it over to the universities, to enable them to pay better salaries to their professors and instructors in science and to increase their research facilities. He confessed frankly that the training in scientific research in the universities is the fountainhead from which success is derived in industrial research and development, and that without industrial research American industries will not gain and hold the leading position in the world to which they may rightfully aspire. What a splendid thing it is to hear a lawyer express an opinion which is in perfect harmony with the opinion of every scientific man in the United States! It has been this mental attitude on the part of the American philanthropists and public-spirited captains of industry like Carnegie, Rockefeller, Swasey, Eastman, and others which has helped us to accomplish wonders in scientific advancement during the last twenty-five years. It has been men of this type who have built research laboratories in the American universities and endowed them generously.

Of the many physical laboratories which have arisen in American universities through private munificence since the time when, fifty years ago, Joseph Henry, Barnard, Draper, Andrew White, and other American scientists started the great movement for higher research in science, there may be mentioned, as an illustration, the Johns Hopkins physical laboratory, the Jefferson laboratory at Harvard, the Sloan laboratory at Yale, the Fayerweather laboratory at Columbia, or the Ryerson laboratory at the University of Chicago. Similar research facilities in other departments of physical science have been presented to American universities by the public-spirited men of the United States. But nothing has illustrated so well the possibilities of intelligent public interest in and generosity to science as the rapid rise of organized American science in the last twenty-five years, culminating in the organization of the National Research Council.

To an untrained eye, necessarily looking at scientific things from a superficial view-point, the National Research Council will appear as a splendid institution organized as our third arm of national defense, an indispensable supplement to the Army and Navy. This conception is perfectly natural, because the time and the conditions which called the Council into existence during the World War were such as to demand immediate scientific efforts for national defense. Other somewhat similar organized efforts were made at that time, but those organizations disappeared into thin air as soon as the armistice of 1918 was signed. The National Research Council did not disappear; it is stronger to-day than ever before, because, although designed to be an effective weapon in times of war, it is fundamentally an instrument of peace. Another superficial view will reveal the National Research Council as a splendid organization for the cultivation of an intimate relationship between abstract science and the industries. This also is as it should be; national defense in its broadest sense demands such co-operation. But both these aspects of the Council, prominent aspects to the superficial observer, reveal only the purely material gains to accrue to this country from the Council’s activities. The anxious question will therefore be: What contributions will this organized scientific activity make to the spiritual welfare of the country?

There are people who think that science with all its splendid achievements is nevertheless materialistic, and that it cannot by itself, no matter how well organized, advance the spiritual welfare of a nation. Some even go so far as to maintain that national endeavors in the direction of very extensive scientific research and very elaborate scientific training are apt to interfere seriously with the spiritual development of our national life. This is particularly true of people who are stirred up, from time to time, by imaginary conflicts between science and religion. I may be permitted here to state briefly how science, as I see it cultivated by the men who are associated in the National Research Council, will contribute to the spiritual welfare of our nation by describing briefly some of its ideals.

Fifty years ago Tyndall, as I have already mentioned, came to America and helped to start the great scientific movement which has culminated in the organization of the National Research Council. At that time Andrew White, the famous president of Cornell, spoke the following historic words in behalf of this historic movement, which I have been watching since its very beginning, and actively aiding whenever an opportunity presented itself:

Now, sir, I maintain that the true spirit of the scientific research, embracing as it does zeal in search for truth, devotion to duty, which such a search imposes, faith in good, as the normal and necessary result of such a search ... that such a spirit is, at this moment, one of the most needed elements in the political progress of our country.

What I maintain, then, is, that this zeal for truth as truth, this faith in the good forever allied to the truth, this devotion to duty, as the result of such faith and zeal, constitute probably the most needed element at this moment in the political regeneration of this country, and that, therefore, the example of our little army of true devotees of science has an exceeding preciousness.

Their zeal, their devotion, their faith, furnish one of those very protests which are most needed against that low tone of political ideas which in its lower strata is political corruption. Their life gives that very example of a high spirit, aim, and work, which the time so greatly needs.

The aims and aspirations and the life of American scientists have not changed since Andrew White spoke these memorable words fifty years ago. A life guided by aims and aspirations such as he describes is a life of saints and not of ordinary materialistic clay. Such a life cannot be attained without unceasing nursing of the spirit and unrelenting suppression of the flesh. Men of Andrew White’s clearness of vision will certainly tell you not only that the disciplined army of American scientists mobilized under the flag of the National Research Council will not interfere with the spiritual development of our national life, but that, on the contrary, nothing else will advance that spiritual development so rapidly and so irresistibly. The intellectual and spiritual discipline which, according to White, our nation needs, is certainly one of the ideals of these men of science.

I shall mention now two other ideals. Just watch on some summer morning how the early rays of the sun arouse the slumbering rose from its blissful dreams, and remember that the rose responds because its body and soul are tuned to the melodies which the glorious sunlight is pouring into its enchanted ear. Remember also that what I have just described is not merely a flowery figure of speech, but that it is a concise description of a beautiful physical relationship, which science has discovered in the life of the rose. I proceed a step further, and ask: Have you ever feasted your joyful eye upon the beauties of the landscape when on a golden May day you behold the blossoming fruit-trees cover as far as your vision can reach the velvety green turf of the numerous orchards of some blessed countryside? What does each of these fruit-trees with its countless blossoms suggest to your imagination? “The honey-hearted fruit of the mellow summer season,” many of you will say. Yes, the blossom and the fruit are so far as the untutored mind can see the beginning and the end of the short chain of apparently commonplace events which make up the annually returning life activity of the humble fruit-tree. Who cares what happens between so beautiful a beginning and so satisfactory an end? The scientist cares; his trained eye detects here an enchanting tale. Every one of those fruit-trees on the golden May day appears to him like a bride arrayed in the gayest of wedding raiment, waiting for the approaching bridegroom. Its countless blossoms invite with longing lips the life-giving kiss of the heavenly groom, the glorious sun. The balmy breath of this golden bridegroom fills the air, kissing the lips of every flower in the gay and festive orchards, and in the juicy pastures and meadows. A heavenly thrill fills the hearts of these enamoured blossoms, when, with sighs of delicious perfume, they, like blushing brides, respond to the tender caresses of the heavenly bridegroom! Yes, there will be honey-hearted fruit in the mellow summer season; the busy bee knows it when it sucks its honey from the joyful bosoms of the blessed brides; it knows that this honey is the first message to you that the marriage between the heavenly bridegroom, the golden sun, and the terrestrial brides, the countless blossoms, will be blessed with many a heavenly offspring, the honey-hearted fruit of the mellow summer season.

This is, I admit, somewhat unusual language for a scientist to use. It is, according to the opinion of many, unsuited to the description of what people call the cold facts of science. They call them so, but is their language justified? The physical facts of science are not cold, unless your soul and your heart are cold. There is white heat somewhere in every physical fact when we decipher correctly the message which it conveys to us. A physical fact denotes activity, otherwise it could not penetrate the depths of our consciousness. Activity is life, in the broadest sense of this word. Death is cold, but life is hot, and it is gross abuse of language to speak of cold facts of science. It is such language that creates prejudice against science, representing its methods as well as its results as devoid of everything which fires the emotional side of man. Every physical fact has two terminals; one is in our consciousness, and the other is in some star which is rejoicing in the blazing vigor of its youth. Just as the life activity of the early blossoms, and of the honey-hearted fruit of the mellow summer season, has its origin in the life-giving breath of the heavenly bridegroom, the glorious sun, so every terrestrial activity, every physical fact, with one of its terminals anchored in our consciousness, can trace its origin to the life-giving breath of some heavenly bridegroom, some burning star. Just explore the path which leads from one of these terminals to the other, and you will discover on each side of that path those beauties which continually thrill the heart of a scientific man. Do that and you will never again speak of the cold facts of science.

Let me for illustration pursue one of these paths for a little distance. Fifty years ago, when as a member of a herdsman’s squad of boys I watched the stars on the black background of a summer midnight sky, I felt that their fight was a language proclaiming the glory of God.

Has science changed that vision of the early childhood days? What does that light convey to my mind to-day? The answer to this question was born during my lifetime, and the gradual unfolding of its profound meaning gave me the sweetest thrills of my life. Faraday and Maxwell told me that light is a manifestation of the activity of electrical force. The discovery of the Roentgen rays and of radioactivity taught me that the primordial sources of electrical force are the positive and the negative electrons, the electrons and the protons, the building stones of matter, and that light is radiation, that is, propagation into space of the electrical energy from the atomic structures in which the electrons with their motions determine the character of the structure and its energy content. Then came Thomson, the same Thomson who scared me away from Cambridge, because I thought that he was too young to be my teacher of physics, and he suggested that the electrons possess an inertial mass on account of the electrical energy which is stored up in them. This suggestion led to the generalization that all electrical energy has mass possessing not only inertia but also gravitational action. Who does not know to-day of this generalization, and who has not heard of Einstein and of his verified prophecy that a beam of light will be deflected by gravitational force? A beam of light represents electrical energy and electrical energy is gravitationally active just like any other mass considered by Newton. A star radiating light radiates electrical energy, and, therefore, it throws out to us a part of its own mass. When this radiation reaches us we can say, therefore, without indulging in figures of speech that the star is visiting us. I am not indulging in a flowery figure of speech when I call solar radiation the balmy breath of the heavenly bridegroom, the glorious sun.

Fifty years ago, instructed by David’s psalms, I found in the light of the stars a heavenly language which proclaims the glory of God, but I did not know how that language reached me, and I hoped that some day I might find out. That hope was in my soul when I landed at Castle Garden. To-day science tells me that the stars themselves bring it to me. Each burning star is a focus of energy, of life-giving activity, which it pours out lavishly into every direction of the energy-hungry space; it pours out the life of its own heart, in order to beget new life. Oh, what a beautiful vista that opens to our imagination, and what new beauties are disclosed by science in the meaning of the words in Genesis: “He breathed into his nostrils the breath of life, and man became a living soul.” The light of the stars is a part of the life-giving breath of God. I never look now upon the starlit vault of the heaven without feeling this divine breath and its quickening action upon my soul. But here I must stop. I feel the heavy hand of the fundamentalist pulling me down, and the icy chill of his disapproving voice reminds me that his theology will not permit an interpretation of the words of Genesis which cannot be understood by people whose knowledge of science is about the same as that of the Assyrians and Chaldeans of several thousand years ago.

I have taken some pains here to point to some beauties in one particular department of physical science. Such beauties abound in every other department of science, and they are in no respect inferior to those which form the subject of the fine arts, like music, painting, sculpture, and poetry. To cultivate the beautiful in science, is, according to my view, the second ideal of the many loyal workers associated in the National Research Council. Will that kind of science interfere with the spiritual development of our national life?

The third ideal may be described as follows: All changeable things are subject to the play of evolution, and are mortal, from the tiny flower in the field to the awe-inspiring cloud figure in the heavens which is called the nebula of Orion. But the laws which the stars and the planets obey in their paths through the heavens never change nor grow old; they are immutable, they are immortal. The elements of the microcosm, the electrons in the atom, are as far as we know immutable and immortal, because man knows no natural process by which the electrons and the laws which they obey can ever be changed. They are not the product of any natural process of evolution known to man. To discover the immutable laws which this substantia, this immutable foundation of the universe, obeys is the highest aim of scientific research. The existence of these eternally unchangeable things brings us face to face with a power which is the eternally immovable background of all physical phenomena. We feel intuitively that science will never penetrate the mysteries beyond it, but our faith encourages us in the belief that there behind the impenetrable veil of this eternal background is the throne of a divine power, the soul of the physical world, the activity of which we contemplate in our research of physical phenomena. I am sure that many loyal members of the National Research Council believe that scientific research will bring us closer to this divinity than any theology invented by man ever did. The cultivation of this belief is certainly one of the ideals of American science, represented by the men who are associated in the National Research Council. In the face of this ideal, there certainly cannot be any conflict between science and religion.

I firmly believe that in the National Research Council we have an organization which represents the mobilized scientific intellect of the United States, which in the pursuit of its lofty ideals will some day succeed in creating in our democracy a profound respect for the services of the highly trained intellect. A democracy which believes that its destiny should be intrusted to the leadership of men of training, discipline, and lofty aspirations and knows how to secure the services of such men is a democracy which is safe for the world. Such a democracy, I believe, was the vision of the scientific men who, fifty years ago, started the great movement for higher endeavor. Such a democracy will lead some day to what I call ideal democracy, that is, a state organism in which each human unit contributes its definite share to the physical and mental activity of the organism. The relation of the individual to the social body in an ideal democracy, as I conceive it, will be very similar to the relation of our cells to our body. Activities of individuals will be coordinated, just as the activities of our cells are, so that one composite mind will guide the resultant activities of the whole social body. This is the mind which my friend, General J. J. Carty, the distinguished engineer and philosopher, calls the “supermind.” A well selected name, because it suggests the name “superman” for ideal democracy, and thus attaches to this somewhat vague concept of recent years a definite meaning. The general is a strong believer in the theory that by evolutionary steps we are gradually approaching the state of ideal democracy. He has lived some forty years in the most perfect industrial organization of the world, the American Telephone and Telegraph Company, and, naturally, he cannot help being an ardent follower and enthusiastic advocate of the belief in the advent of ideal democracy. But is there anything in the history of the evolutionary progress of the world which justifies this comforting belief? I think there is.

The Greeks of old believed that the world started with chaos, and that out of the chaos came the cosmos. They were optimists, because in their theory coordination, order, and beauty were evolved out of hideous disorder. There are many pessimists to-day who prophesy the opposite course of development of this, in their opinion, most wicked world. Modern science confirms the ancient belief of the Greeks in a remarkable manner. Nothing else so resembles that chaotic start of the world which the ancients conceived as does the activity of a young star, because nothing more completely illustrates lack of order and coordination. Each one of its pulsating atoms is indifferent to the white-heat activity of the myriads of neighboring atoms, and each one of them pours out its energy in an unconcerned and most prodigal manner into the energy-hungry space. Consider our sun, as an illustration. Tiny energy units are projected from myriads and myriads of its atomic guns in haphazard fashion, apparently without any definite aim. These energy units are propagated through space in a perfectly chaotic fashion, without a definite object in view so far as science can tell. But their fate and destiny are fixed and determined as soon as they arrive on mother earth and are caught by the leaves, the blossoms, and the ripening fruit of the fields, meadows, and orchards, and by the endless nets of the all embracing oceans. The chaotic, non-coordinated energy-swarms are thus imprisoned and made to work together with a definite aim and for a definite purpose. The joys and beauties of our annual seasons will tell you the story of this wonderful transformation of primordial energy from the chaos of the young stars, white hot with joy of life, to the cosmos of the old, cold, and moribund earth. The principal lesson of this story is the great physical fact that terrestrial organisms have instrumentalities with which they coordinate the non-coordinated, thus bringing the order of old age out of the disorder of youth, final cosmos out of primordial chaos. Is not the existence of these instrumentalities the fundamental guiding principle in the development of terrestrial life? Does not all our experience teach us that progress means more complete coordination of all natural activities, the activities of the atoms in the burning stars as well as of the cells in our terrestrial bodies? Call this progress evolution, or anything else you please, it certainly is there, and it leads to a more beautiful and a more perfect order of things. The most nearly perfect product of these coordinating instrumentalities is man--after man, what? Yes, a superman; but what will that superman be? The present man, with his physical and mental faculties more highly developed?--or the superman as represented by what I call ideal democracy? Carty, guided by his life experience and by the opinion of some biologists and philosophers, favors the latter view. There certainly is something in the evolutionary progress of the world which favors the view that the coordinating instrumentalities which guide the activities of every organism, and which are very powerful in man, may enable us some day to find a way of coordinating the non-coordinated activities of the many millions of individuals of a great community like these United States, and thus of creating an ideal democracy. I see in the organization of the National Research Council the first step in that direction.

THE WHITE HOUSE WASHINGTON

October 14, 1922.

My dear Doctor Pupin:

I accept with regret your resignation as a member of the National Advisory Committee for Aeronautics. In doing so I want to express to you the thanks of the Government and people of the United States of your services as a member of the National Advisory Committee for Aeronautics since its organization in 1915.

I take this occasion to record recognition and appreciation of the fact that, as Chairman of the Subcommittee on Aircraft Communications, during the World War you undertook to develop a reliable means of communication between aircraft in flight, and that, by virtue of experiments conducted and directed in your own laboratory, you were successful in contributing in an important respect to the development of one of the great marvels of our age, the radio telephone.

I regret that you cannot continue to devote your talents to the scientific study of the problems of flight as a member of the National Advisory Committee for Aeronautics.

Most sincerely yours, _Warren G. Harding_

Dr. Michael I. Pupin, Columbia University, New York City.

Ideal democracy, if attainable at all, will certainly be attainable in our country, whose traditions are gradually eliminating racial hatreds and suspicions and making them unknown human passions on this blessed continent. If I have ever contributed anything substantial to the progress of this splendid movement, whether as an immigrant or as an inventor, it has been most amply rewarded by the generous spirit of the letter on the opposite page, written by a man whom I had the honor of knowing personally and who to me always represented the ideal type of a genuine American.

* * * * *

These few concluding lines I wrote on the day when this good American breathed his last. His memory will always encourage us in the belief that our blessed country is destined to become the first ideal democracy of the world.

INDEX

Action and reaction in electricity, 296-299

Adams, John Crouch, 181

Adams, President, 315

Adelphi Academy, Brooklyn, 108-110, 120

Alexander the Liberator, Czar, 8, 9

Alhazan, 204

Alps, travels in, 146-150, 208

Alternating-current theory, 283-289, 294

American Association for the Advancement of Science, 291, 359

American Institute of Electrical Engineers, 283, 337, 348, 359-362

American Institute of Mining and Metallurgical Engineers, 359

_American Journal of Science_, 299

American Mathematical Society, 352

American Philosophical Society, 363

American Physical Society, 351-353, 358, 360

American scientific progress, 279-384 _et passim_

American Society of Civil Engineers, 359

American Society of Mechanical Engineers, 359, 364

American Telephone and Telegraph Company, 335, 338-340, 342, 345, 384

Americanization, 318 _et passim_

Ames, Joseph Sweetman, 256

Ampère, 187, 257

Appel, 257

Arago, 257

Archimedes, 193, 194, 221

Aristides, 92

Aristotle, 20

Armour & Co., 344

Armstrong, Major E. H., 19, 342, 358

Armstrong, Hamilton Fish, 316

Arran (island), 212-217

Aspern (battle), 6

_Astronomy and Astrophysics_, 293

Atomic structure, 356, 357, 384-386. _See also_ Matter, nature of, _and_ Electrons

Bacon, Roger, 204

Bagpiper, Serbian, 19 _et passim_

Baker’s wagon, painting of, 62, 63

Banat, life and experiences in, 2-22, 95, 96, 152, 157-166, 324, 346

Barnard, President, of Columbia University, 104, 128, 135, 183, 185, 197, 199-202, 205, 220, 230, 278, 290, 291, 320, 375

Barrett, Lawrence, 89

Batikin, Baba, 6-8, 12, 29, 46, 112, 131

Becquerel, 350

Beecher, Doctor Henry Ward, 105-108, 124, 129, 136, 156, 163

Belgrade, experiences in, 153, 162

Belgrade University, 317

Bell, Alexander Graham, 299, 300, 319

Berlin, experiences and study in, 229-278, 309, 318, 338

Berlin, studies at University of, 229-278, 318, 338

Bessemer process, 259

_Bible, The_, 10, 18, 20, 21, 67, 243, 245, 246, 381, 382

Bilharz, 85-95, 100-104, 106, 108, 112, 113, 130, 131, 140, 247, 318

Biscuit factory experiences, 72-76, 78-95

Bismarck, 247, 253, 261, 275

Booth, Edwin, 89, 129

Bowery Mission, 66, 67, 84

Bradley, 285

Brown (New Jersey farmer), 66-68

Browning, Oscar, 143, 171-173

Bryant, William Cullen, 89, 93, 102

Budapest experiences, 25, 30, 150-152, 155, 162

Bukovala’s mill, 168, 169, 243

Bull, Doctor, 307

Burgess, Professor, 128, 135

Butler, Prescott Hall, 307, 308

Butler, President Nicholas Murray, 60

Cambridge University, 143-146, 156, 164, 169-187, 190-211, 309, 318, 321, 338, 349, 381

Campbell, 187, 211, 213, 228

Canal rays, 304

Cane rush, Columbia, 114, 117, 118

Carnegie, Andrew, 259, 360-365, 375

Carnegie Corporation of New York, 371

Carnegie Institution of Washington, 362, 366

Carnot, Sadi, 186, 193

Carter, Mr. (of Norfolk), 328

Carty, General J. J., 384, 387

Castle Garden, 1, 2, 39-41, 43, 45, 98, 99, 104, 105, 142, 148, 278 _et passim_

Cathode rays, 304, 305 _et passim_

Cavendish, Lord, 273

Cavendish Physics Laboratory, 183, 198, 199, 273

Cayley, 192

Centennial Exposition, Philadelphia, 78

Century Club, 308

Chanler, John Armstrong, 135

Charnoyevich, Patriarch, 3, 4

Chicago University, 376

Choate, Joseph, 288

Christian of West Street, 60-64, 72, 73, 80, 92, 104, 247

Christopher (kindling-wood peddler), 111, 117

Chuchuk Stana, 54, 55

Church in Delaware City, 52; in Brooklyn, 105-107

Cicero, 112

Civil War, United States, 315, 360, 366

Clark, Latimer, 361, 362

Columbia College and University, 98-110, 112-123, 125-130, 132-137, 145, 160, 161, 197-199, 201, 202, 218, 276-310, 320-322, 326, 331, 352, 359, 361, 376 _et passim_

Cooper, Peter, 77, 319

Cooper Union, 64-66, 73, 75-80, 95, 98, 130, 132, 319

Copernicus, 195

Cornell University, 377

Corrie, summer at, 212-217

Cortlandt Street cracker factory, 72-76, 78-95

Coulomb’s law, 227, 228

Cracker-factory experiences, 72-76, 78-95

Crawford, F. Marion, 125, 143

Crocker, Professor Francis Bacon, 273, 279-282, 285, 286, 302, 310

Crookes, William, 303

Curie, Madame, 350

Custozza (battle), 7, 9

Danube, journey on, 23-25

Darboux, 257

Darwin, 91, 195

Davy, 202

Dayton, New Jersey, farm experiences, 66-68

Declaration of Independence, 56, 75, 76, 78, 79, 98, 103, 153, 163

De Forest, Lee, 342, 358

Delaware farm experiences, 45-56

Democracy, 383-387

De Morgan, Professor, 176

Dennis, Doctor Frederick Shepard, 323-324

Dernburg, 69

de Tocqueville, 203, 204, 256, 319, 320

Devonshire, Duke of, 273

DeWitt, 121

Dindorf (philologist), 131

Direct current theory, 283-289

Discharge of electricity in corona form, 293

Distortions in alternating current, 294

Draper, Doctor John William, 122, 202, 290, 291, 320, 375

Duncan, Doctor Louis, 289

Dunn, Gano, 292, 367, 368

Eastman, George, 375

Eastman Kodak Company, 341

Ebert, 293

Edison, Thomas, 135, 299, 307, 309, 319

Edison General Electric Company, 287, 289

Eilers (of cracker factory), 72

Einstein, 354-356

Electrical Congress, Chicago, 287, 289

Electrical Engineering Department, Columbia, 276-310

_Electrical Researches_ (Faraday), 211, 213, 222-229

Electricity, _passim_

_Electricity_, 308, 309

Electromagnetic Induction, 133, 134

Electromagnetic theory of light and matter, 211, 218-229, 236-241, 264-271, 278, 293-295, 303-306, 349-351, 354-358

Electron Physics, 353-358

Electrons, 349-352, 356, 357, 381

Emmet, Devereux, 119

Engineering Foundation, 365-368

English, study of, 50, 55, 88

Ericsson, 78

Ether, 354, 355

Eugene of Savoy, Prince, 5

Evarts, William, 93

_Evening Post_, New York, 93

Evolution, 384-387

Ewing, General Thomas, 102

_Experimental Researches in Electricity_ (Faraday), 211, 213, 222-229

Farad (electrical unit), 273

Faraday, Michael, 133-135, 193, 195, 199, 202, 205, 210-213, 215, 219-230, 233-241, 243, 245, 246, 249, 264, 267, 268, 270-274, 278, 281, 284, 303, 305, 306, 349, 351, 380

_Faraday as Discoverer_ (Tyndall), 235

Fayerweather Laboratory, 376

Fehispan, governor of Torontal, 161-164

Fish, Frederick P., 340

Fiske, 352

Fizeau, 257

Fluorescent screens, 307, 309

Foucault, 257

Fourier, 257

France, summer in, 187-189; visit to, 257, 258, 262

Francis, Emperor, 5

Francis Joseph, Emperor, 9, 22

Franklin, Benjamin, 12, 13, 19, 29, 39, 45, 57, 74, 105, 124, 193, 202, 266, 312, 315, 360

Franklin Institute, 348

Fred (friend of Jim the engineer), 83

Frederick, Crown Prince, 233, 275

Frederick the Great, 5-7

French scientific progress, 257, 262

Fresnel, 204, 257

Frushka Gora (mountain), 24

Gabriel, son of Milutin, 165-169

Gaenserndorf, 25, 26, 28

Galileo, 193-195, 221, 297, 333

Gallatin, Albert R., 296

Garibaldi, 8, 9

Geltner, Professor, 275

General Electric Company, 289, 341, 358

General Relativity Theory, 355

Generators, electrical, 281, 282

Germans, 30, 31, 35; social democracy, 89; scientific progress, 208, 256-264 _et passim_

Germany, studies in, 229-278, 318, 338

Gessler, 147

Ghiga (peasant), 161

Gibbons, Cardinal, 59, 60

Gibbs, Professor Josiah Willard, 184, 186, 207, 256, 257, 277, 278

Godfather of author, 160

Goethe, 86

Goldstein, Doctor, 303-305

Goodyear, 319

Graduation from Columbia, 136, 137

Grant, 79

Gravitation, nature of, 354

Green, Mr. (of Marconi Co.), 343-345

Grounding, importance of electrical, 301, 302

Hale, Doctor George Ellery, 294, 362, 367, 368

Hamilton, Alexander, 100, 101, 103, 107, 118, 121, 128, 193, 315

Hamilton, Duke of, 212

Hamilton Hall, Columbia University, 100, 101

Harding, President Warren G., 386, 387

Harvard University, 256, 376

Hayduk Velyko, 6, 54, 55

Hayes, 91, 93

Heat, nature of, 76, 185, 186

_Heat as a Mode of Motion_ (Tyndall), 102

Heaviside, 333-335

Hebert Prize of French Academy, 348

Helmholtz, Hermann von, 193, 195, 200, 208, 210, 218, 225, 230-243, 248, 249, 251, 256-258, 260-264, 271, 275, 277, 287, 289, 294, 295, 298, 299, 303-305, 341, 344

Henry (electrical unit), 273

Henry, Frank, 114, 115

Henry, Joseph, 77, 183, 201, 202, 205, 220, 266, 271-274, 284, 290, 291, 319, 320, 358, 366, 375

Henry, Patrick, 88

Herdsman, experiences in Idvor as, 14-21, 301, 302, 333, 334

Hermite, 257

Herschel, William, 202

Hertz, Doctor Heinrich, 219, 221, 228, 263-272, 301, 305

Hertzian oscillator, 265-270

Hilendar (monastery), 70

Hittorf, 303

Hoffman, 263

Hohenzollern, William, 112

Homer, 86, 112, 130, 131

Hook, 334

Hoover, Herbert, 314

Horace, 87

Horse training in Norfolk, 324-326

Howe, 77

Hunt, Robert, 102, 130

Huss, Yan, 33

Hutchinson, Doctor Cary T., 337

Huxley, 91

Idealism in American science, 311-384

Idvor, life and experiences in, 2-22, 34, 36, 138-143, 156-169, 189-191, 215, 242-248, 301, 302, 346

Inductance coils, 335-342, 345

Induction, Electromagnetic, 133, 134

Jackson, A. V. Williams, 275, 276

Jacoby, 352

Jay, John, 100, 101, 103, 107, 121, 143, 315

Jefferson, Thomas, 74, 315

Jefferson physical laboratory, Harvard, 256, 376

Jim (boiler-room engineer), 74-76, 78-85, 92, 95, 104, 106, 108, 130, 193

Johns Hopkins University, 59, 60, 183, 184, 198, 199, 288-292, 376

Karageorge, 6-9

Karlovci, 23, 24, 26, 30, 57, 68, 77, 97, 153-155, 162

Kellogg, Doctor Vernon, 373, 375

Kelvin, Lord (Sir William Thomson), 182, 183, 266, 287, 304, 332, 333, 335, 338, 363

Kepler, 204

Kessedjia, Moussa, 115

Kirchhoff, Gustav Robert, 204, 233, 258, 261, 263, 332, 333, 335, 338

Koenig, Professor Arthur, 230-232, 234, 235, 240, 241, 248, 249

Kos (Slovenian teacher), 19-21, 32, 76, 95, 241, 244, 266, 312

Kossovo (battle), 7, 54

Kossuth, 163

Krupp, 259

Labor Bureau, Castle Garden, 40, 41

La Grange, 187, 189, 190, 193, 194, 204, 206, 207, 210, 213, 257, 330, 331, 335, 338, 339, 348

Lansing, Robert, 2

Laplace, 187, 257

Lectures given for laboratory equipment, 280, 281

Lenard, Professor, 305

Leopold I, Emperor, 3, 4

_Life of Maxwell_ (Campbell), 187

Light, nature of, 19-21, 133, 144, 166, 171, 201, 202, 211, 218-221, 240, 244, 271

Lincoln, Abraham, 8, 9, 29, 39, 55, 74, 79, 92, 105, 107, 193, 315, 319, 360, 366, 372

Lines of force, 226-230, 236-240, 265-271

Ling (of King’s College choir), 172

Lippmann, 257

Livingston, Chancellor, 100, 101, 103, 107, 121, 137

Longfellow, Henry W., 87, 102, 149

Lorentz, Professor, 355

Low, President, 307, 331

Lucerne experiences, 146-150

Lukanitch family, 95-99, 105, 106, 116, 136

Lyermontoff (poet), 18

Lyubomir, 168

Macmillan homestead, Corrie, 216, 217

Macnamara, Jane, 82, 86

Madge of Corrie, 213, 214, 216

Magnetism, 218-229

Marconi, 301, 302

Marconi Company of America, 343-345, 347

Maria Theresa, Empress, 5

Marko, Prince, 8, 9, 29, 46, 54, 55, 115, 195

Massachusetts Institute of Technology, 359

Matter, nature of, 218-221, 354. _See also_ Electrons, Atomic structure, etc.

_Matter and Motion_ (Maxwell), 179, 185, 193

Maxwell, James Clerk, 133-135, 144, 145, 153, 166, 171, 174-176, 179-181, 183-187, 190, 193-195, 197, 198, 200, 201, 204, 206, 208, 210-214, 217-222, 229, 234-243, 249, 256, 264, 267, 270-274, 278, 284, 303, 305, 306, 320, 321, 350, 352, 380

Mayo-Smith, Professor Richmond, 128

McCormick, 77, 319

McCullough, John, 89

_Méchanique Analytique_ (La Grange), 189, 193

“Men of Progress” (painting), 77, 78, 130, 319

Merriam, Professor, 128, 131, 134, 135, 143

Michael (college janitor), 114

Michelson, 354, 355

Miletich, Svetozar, 21, 22

Milton, 102

Moltke, 253, 261, 262, 275

Momentum in electricity, 297, 298

Morley, 354, 355

Morse, 77, 319

Motion, electric (in rarefied gases), 303-306

Moula Pasha, 6

Mount Wilson Astronomical Observatory, 294, 362, 367

Mueller (glass-blower), 303, 304

Napoleon, 5-7

Nassau Hall, Princeton, 69, 72, 84, 87, 88, 99, 101, 103

National Academy of Sciences, 205, 272, 360, 366, 367, 369

National Institute of Social Sciences, 339, 348

National Research Council, 317, 366-383, 387

Naturalization, 136, 137

_Nature_, 192, 200, 201, 205, 206, 208, 221, 236

Nemanya, Zhupan, 10

“Neptune, Father,” 139-142

Nettleton, Mr. (of Norfolk), 327-329

New England Cracker Factory, 72-76, 78-95

New Physics, 349, 353-358

New York, landing in, 37-42

New York Academy of Sciences, 309

New York Mathematical Society, 352

New York Rapid Transit Commission, 289

Newton, 174, 177, 179, 180, 186, 193-196, 204, 210, 211, 221, 225, 282, 283, 296, 334, 381

Niagara Falls Power and Construction Company, 287, 288

Nikola (Serbian cigarette seller), 252-254, 258, 274-276

Niven, W. D., 143-146, 156, 171, 174-176, 178, 180, 181, 186, 197, 240

Norfolk, Conn., life at, 322-329

Nyegosh, Bishop (poet), 20, 68, 112

Octagon class, 119, 121

Oerstedt, 221, 224

Osborn, Henry Fairfield, 71

Oscillator, Hertzian, 265-270, 301, 302

Oxen herding in Idvor, 14-21, 301, 302, 333, 334

Palacky, 31-33

Panchevo, experiences in, 12, 20-24, 29, 31, 35, 154-156, 163, 312-318

Paris peace conference, 2, 312, 314, 315

Parkinson, Stephen, 182, 183

Parsons, William Barclay, 286

Pashitch, Premier, 312

Paul (of the cracker factory), 79, 80

Penn, William, 45, 57

Perrin, 349

Philadelphia, early experiences in, 56, 57

Phonograph, 299, 300

Physical Society, Berlin, 263-271

Physics, New and Electron, 349, 353-358

Pickernell, Mr., 335

Planck, 261, 277

_Plea for Pure Science, A_ (Rowland), 291

Plymouth Church, Brooklyn, 105-108, 129

_Poetry of Science, The_ (Hunt), 102

Poincaré, 257

Pornic, vacation in, 187-189

Power distribution, electrical, 289

_Practical Aspects of the Alternating Current Theory_ (Pupin), lecture, 283, 284

Prague, experiences in, 21-35, 163, 164, 248

Preceptorial system in college, 326

Princeton University, 69-72, 84, 87, 101, 143, 272, 316, 326

Privilegia (document), 4, 5, 9

Problems of physical universe, 354

Prussians, 247-255. _See also_ Germans

Pupin coil, 335-342, 345

Pupin, Constantine (father of author), 2, 21-23, 34, 158

Pupin, Mrs. Michael, 276-278, 292, 310, 322, 330-332

Pupin, Olympiada (mother of author), 2, 10-12, 22, 23, 34, 157-160, 168, 169, 190, 191, 215, 242-246, 249-251, 255

Pyne, Moses Taylor, 69

Radichevich, Branko, 154

Radio, 295-299, 303, 342, 343, 357, 358

Radioactivity, 350, 351, 381

Radium, 350

Rayleigh, Lord, 144, 175, 176, 181, 184, 197, 213, 240, 330, 352

Regnault, 182

Relativity theories, 355

Research, progress of America in, 279-384

Resonance, 295-299

Resonators, electrical, 295-301

Reymond, DuBois, 258, 263

Rieger, 31-33

Rittenhouse, 202

Rives, George, 143

Rives, Reginald, 326

Rockefeller, John D., 375

Rockefeller Foundation, 371

Rockefeller General Education Board, 371

Roentgen, 305, 306, 349, 350

Roentgen rays, 302, 303, 305, 329, 349, 380. _See also_ X-rays

Rood, Professor, 133, 134, 199

Routh, Doctor John Edward, 174-180, 182, 185-187, 189, 197, 213

Rowland, Henry Augustus, 183, 184, 256, 287-292, 295, 298, 299, 352-354, 357, 358

Royal Serbian Academy, 317

Rumford, Count (Benjamin Thompson), 202, 218

Rutherford, Sir Ernest, 352, 353

Rutherford Park, N. J., summer at, 111-113

Rutherfurd, Lewis, 122

Rutherfurd, Lewis Morris, 122-129, 133-135, 144

Rutherfurd, Winthrop, 122-126, 144

Ryerson Laboratory, 376

St. Sava, 10-12, 33, 35, 68, 70, 77, 141, 158, 250

School life in Idvor, 10-12; in Panchevo, 12

_Science_, 309

_Scientific American_, 74

Scientific progress and research, 202-206, 218-230, 256-264, 279-310, 311-384 _et passim_

Scientific research, American progress in, 279-310

Scientific research and the universities, 341-343, 358-360, 375, 376

Scotland, summer in, 212-217

Serbian Child Welfare Association of America, 312

Serbs, 1-28, 151-168 _et passim_

Shakespeare, 86, 89, 129

Shepard, Doctor Charles, 108-111, 136

Siemens, Ernst Werner von, 260, 275, 289, 344

Siemens and Halske, 344, 345

Signalling by herdsmen of Idvor, 15-21, 301, 302, 333, 334

Sing Sing prison, 284, 287

Singers, Serbian, 155

Sloan Laboratory, 376

Smith, Professor Monroe, 128

Smithsonian Institution, 272

Snellius, 204

Sobiesky, King, 3

Solar corona, 293

Solar phenomena, electromagnetic theory of, 293, 294

Sorbonne, the, 257

Sound, early herdsman’s experiments, 15-21, 301, 302; transmission, 333

South St. Mary, Md., 58

Special Relativity Theory, 355

Sprague, Frank J., 287

Steel industry, German, 259

Stillwell, Lewis B., 287

Stokes, Sir George Gabriel, 175, 181, 192, 197, 204, 213, 240

Stowe, Harriet Beecher, 39, 105

Strazhilovo, Will, 162

Subways, 289

_Summary and Conclusions_ (Tyndall), 204-208

_Sun_, New York, 74, 93, 94

Swasey, Ambrose, 363-365, 368, 369, 375

Swift Company, 344

Switzerland, experiences in, 146-150, 208, 330, 331

Telegraphy, 234, 300, 347, 348

Telephony, 299, 300, 331-342, 345-348

Tell, William, 147

_Tendencies of Modern Electrical Research_ (Pupin), 309

Tesla, 285

_Theory of Heat_ (Maxwell), 185, 193

Theses for doctor’s degree, 277

Thomas, Sidney Gilchrist, 259, 260

Thompson, Benjamin (Count Rumford), 202, 218

Thomson, Elihu, 284, 286, 287, 289

Thomson-Houston Company, 287, 289

Thomson, Sir John Joseph, 198, 292, 293, 306, 349, 350, 352, 356, 381

Thomson, Sir William (Lord Kelvin), 182, 183, 266, 287, 304, 332, 333, 335, 338, 363

Tilden, 91

Tilton, 105

Tolstoy, 152

Traction, electrical, 286, 287

Traditions, 104, 105, 120, 121

_Transactions of the American Institute of Electrical Engineers_, 299

Transmission and motion of electricity, 287, 303-306

_Tribune_, New York, 91

Tuning, electrical, 19, 295-299. _See also_ Radio

Tyndall, John, 102, 130, 132, 186, 199-213, 220-222, 230, 235, 236, 240, 283, 291, 321, 351, 377

Tyndall Fellowship, 199, 209

_Uncle Tom’s Cabin_ (Stowe), 29, 39, 105, 156

United Engineering Society, 361-365

Vacuum tubes, 303-306, 349, 357, 358

Van Amringe, Professor Howard, 128, 352

_Van Nostrand Magazine_, 179

Vaschy, 333-335

Velocity, electrical, 234

Vibratory motion, transmission of, 330-338

Vienna experiences, 97, 150-152, 154, 155

“Vila” of Delaware farm, 47-58, 80, 88

Vila Raviyoyla, 195

Vitellio, 204

Vreeland, Mr. (inventor of oscillator), 19

War, World, 312, 315, 316, 333, 334, 344, 359, 360, 366, 369-371, 376

Warner, Mr., 364

Warner and Swasey shops, 364

Washington, George, 54, 55, 100, 137, 193, 315, 372

Washington, Martha, 54

Watt, James, 75

Webster, Arthur Gordon, 255-257, 308

Webster, Daniel, 88, 315

Webster, Professor at Adelphi Academy, 108, 109

Welch, Professor William, 184

Western Electric Company, 340, 358

Westinghouse Company, 284, 341

_Westphalia_ (ship), 35-39, 138

Wheeler, Doctor Schuyler Skaats, 361

White, Andrew D., 203, 220, 274, 320, 375, 377, 378

Widener, Mr., 326

William I, Emperor, 252, 275

Wilson, President Woodrow, 2, 71, 313-315, 367, 369, 370

“Wilson Day” in Panchevo, 312-318

Wireless, 295-299, 303, 342, 343, 357, 358

_Worcester Gazette_, 308

World War, 312, 315, 316, 333, 334, 344, 359, 360, 366, 369-371, 376

X-rays, 305-310, 330, 332, 350, 351. _See also_ Roentgen rays

Yale University, 184, 185, 376

Yevrosima (mother of Prince Marko), 54, 195

Youmans, 320

Young, Professor Charles A., 293

Young, Thomas, 204

Zhivkovich, Protoyeray, 20, 22, 31, 32, 156, 316

Zhizhka (general), 33

Transcriber’s Note:

Punctuation has been standardised. Spelling and variations in hyphenation have been retained as they appeared in the original publication except as follows:

Page 22 Zivkovich came to my defense _changed to_ Zhivkovich came to my defense

Page 96 and a a big tear threatened _changed to_ and a big tear threatened

Page 257 Hermite, Darboux, Appell, Lippmann, _changed to_ Hermite, Darboux, Appel, Lippmann,

Page 308 adressed a letter to the _changed to_ addressed a letter to the

Page 337 communication to the Amercian Institute _changed to_ communication to the American Institute