Chapter XII: The National Research Council 349 (12)

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: