Chapter XII: The National Research Council 349 (10)

The Faraday-Maxwell electromagnetic theory extended the well-known electrical and magnetic actions and reactions from conductors to non-conductors, including the vacuum. If this theory is correct, then electromagnetic disturbances will be propagated from their source to all parts of space, and not along conductors only, by definite waves travelling at a definite velocity.

Maxwell’s calculation showed that electromagnetic disturbances are propagated through insulators in the same manner as light is propagated, and that, therefore, _light is in all probability an electromagnetic disturbance_. This is the substance of Maxwell’s electromagnetic theory of light; it is his answer to the question: “What is Light?”

That, broadly stated, was the information which Helmholtz first conveyed to me in terms which I understood clearly; and for this service I have always been profoundly grateful to him. He showed me that the Faraday-Maxwell electromagnetic theory was incomparably simpler than I thought it to be, and also much more beautiful. I do not believe that in 1881 there was another physicist in continental Europe who could have given me that information, and perhaps not even in 1886, when I first read that wonderful address. My friend Niven in Cambridge, editor of the second edition of Maxwell’s great mathematical treatise, never volunteered to tell me how Maxwell answered the question: “What is Light?” Neither did Tyndall. I do not know whether Rayleigh or Stokes or anybody else in Cambridge when I was there could have done it as well as Helmholtz did. I shall describe later an historical event which indicates that they probably could not.

Toward the end of that semester I felt certain that I understood Helmholtz’s interpretation of Faraday, and of Maxwell’s answer to the question: “What is Light?” I then managed to have another discussion with Professor Koenig. He listened most attentively to my description of the Faraday-Maxwell electromagnetic theory as I had gathered it from Helmholtz; and it was, as far as I can recall it now, very similar to the description given above. This was my first lecture at the University of Berlin, delivered to a very intelligent audience of one person, dear little Doctor Koenig. It would have been a signal success if I had not closed it with a tactless remark, to the effect that Helmholtz, in his Faraday address, rejected every one of the four German electrical theories, and declared himself in favor of Faraday and Maxwell. Helmholtz intimated, and unfortunately I did not hesitate to say so to Doctor Koenig, that physicists of continental Europe had not accepted the English theory because it was above their heads. Finally I said that all this explained most satisfactorily why Kirchhoff paid so little attention to Faraday and Maxwell. Koenig looked at his watch, and, as if suddenly remembering an important engagement, he turned on his heels and left without his customary bow and greeting. His national pride was evidently wounded. I regretted it deeply. I did my best to make up with him and succeeded finally, by admitting unreservedly that, after all, the Faraday-Maxwell electromagnetic theory rested upon several bold assumptions which had not yet been verified by experiment. The German electrical theories also rested upon unverified assumptions, but I said nothing about that for fear of endangering the re-established _entente cordiale_ between Doctor Koenig and myself.

Excellenz von Helmholtz had left Berlin for his summer vacation; among my German fellow students at the Physical Institute there was not much interest in Faraday and Maxwell. I do not know how difficult it is to conceal a deep secret, because I never had one to conceal; but I do know how hard it is to keep imprisoned in one’s heart the joy which one feels when the light of new knowledge rises above one’s mental horizon. I had planned to visit my mother during that summer; I had not seen her for nearly two years. Perhaps, I thought, I might find somebody in my native Banat to whom I could disclose the joy which I received from the revelation which came to me through Helmholtz. Kos, my teacher of fifteen years before in Panchevo, was no longer among the living; in fact, that school was no longer in existence, the Hungarian régime having replaced it by a Hungarian school. I would have liked nothing better than to tell him how Maxwell answered the question: “What is Light?”

* * * * *

In the beginning of August of that summer I was in Idvor again, carrying with me the two volumes of Helmholtz’s addresses. My mother received me with a heart which she described as overflowing with blessings which my visit and the visit of God’s grace upon Idvor was pouring into it. The golden harvest was all in, and it was the richest that Idvor had seen for many a year; the grapes in the old vineyards were beginning to ripen, and the peach-trees among the rows of vines in the vineyards were heavily loaded with the juicy fruit of ambrosial flavor; the melons in the endless melon patches looked big and flourishing, and suggested that at any moment they might burst with the fulness of their exuberant prosperity. The dark-green corn-fields seemed to groan under the heavy load of the young ears of corn, and the pasturelands alongside of the corn-fields were alive with flocks of sheep, carrying udders which reminded one of the abundance of milk, cream, and cheese such as Idvor had seldom seen. All these things my mother pointed out to me, and she assured me that by the grace of God she was enabled to be a bountiful hostess to me, because she had everything in great abundance which she knew I always liked. Melons, cooled at the bottom of a deep well; grapes and peaches picked before sunrise and covered up with vine-leaves to keep them cool and fresh; young corn picked late in the afternoon and roasted in the evening in front of a wood fire; cream from sheep’s milk supplied by the blessed sheep the day before. All these were sweet and delicious things; but have you ever tasted them when their sweetness is flavored by the love of an indulgent mother? If you have not, then you do not know what sweetness is. I warned my mother that her hospitality might transform me, as three years before, into a pampered pet who would be too slow to return to Berlin. Reminding me of the story which she had told me two years before, describing my climb up the steep and slippery roof of Bukovala’s mill in search of a star, she said: “You have done much climbing during the last two years, and I know that in your climbing you have found several real stars from heaven. One of them is now in Berlin and no sweets in Idvor will keep you away from it.” She guessed right, undoubtedly because she observed with what joy I kept up, during that vacation, my reading of Helmholtz’s addresses.

Many a night during that summer I spent in my mother’s vineyard sleeping on sheepskins under the open sky and looking at the stars at which I looked fifteen years before, when I helped the herdsman to guard the village oxen during the starlit summer nights. I remembered the puzzles which I tried to solve at that time concerning the nature of sound and of light, succeeding in the case of sound and failing in the case of light. I rejoiced at the feeling that I had finally succeeded in finding from Faraday and Maxwell through Helmholtz that sound and light resembled each other, one being a vibration of matter, and the other a vibration of electricity. The fact that I did not know what electricity is did not disturb me, because I did not know what matter is. Nobody knows the exact nature of these even to-day, except, as Faraday suggested, that they are manifestations of force. David’s nineteenth Psalm, which I recited so often fifteen years before during my training in herdsmanship, conveyed a different meaning, and so did Lyermontoff’s line which says that “star speaketh to star.” They certainly spoke to me during those glorious August nights, when, covered with sheepskins, I lay in my mother’s vineyard and amid the deep silence of slumbering earth I listened to their heavenly tales. The more I listened the more I became reconciled to the idea that the language of the stars reaches me in the same way that human language does, when it speeds on over the telephone wire, conveyed by vibratory electric and magnetic forces; except that in the transmission of the telephonic message the vibratory forces glide along the conducting wire, whereas the stars pour out their waves of vibratory electromagnetic forces in ever-expanding spheres so that they may carry the heavenly message to every other star and to everything that lives, and to everything that has a being. I could not help telling my mother of my new knowledge which persuaded me that light is a vibration of electricity, very much like the vibration of the melodious string described in the Serbian figure of speech, familiar to her, which says:

My heart quivers like the melodious string under the guslar’s bow.

She always was the most attentive audience that I ever had, and the most responsive. Her wonderful memory, even at that time when she was seventy years of age, assigned to every essential event of her experience a suitable place, so that it became a vital chord in the symphony of her life. She never heard anything worth hearing without responding with one of these harmonious chords, and this was particularly true when I was speaking to her. On this particular occasion, referring to my new knowledge which I brought to Idvor from Berlin, she reminded me of my new knowledge about lightning which I had acquired from my teacher Kos, in Panchevo, some fifteen years before, and afterward tried to explain it to my father and his peasant friends, who accused me of heresy; and she recalled her defense of me. She suggested, jokingly, that if my father and his old friends had still been living they would perhaps accuse me again of heresy on account of some old legends which clashed with my new knowledge; and she assured me that she would defend me again. “God sends sunlight,” she said, “to melt the ice and snow of the early spring, and to resurrect from death everything that lay lifeless in the cold grave of the bosom of mother earth, chilled by the icy breath of winter. The same sunlight,” she continued, “awakens the fields, the meadows, and the pasturelands, and bids them raise the daily bread of man and beast; it also ripens the honey-hearted fruit in orchards and vineyards. If that is all done by the same heavenly force which hurls the lightning across the sombre summer clouds pregnant with showers, and also carries, as you say, the humble human voice over the wires between distant peoples, then I see in it a new proof of God’s infinite wisdom which uses one means only to do great things as well as small. Ko che ko Bog! Who can fathom the power of God!” I reminded her of her saying which she often addressed to me when I was a boy and which I quoted before, namely: “Knowledge is the golden ladder over which we climb to heaven,” and asked her whether she included in this the knowledge which I was describing to her.

“I include every knowledge,” she said, “which brings me nearer to God; and this new knowledge certainly does. Just think of it, my son: God has been sending his messages from star to star and, according to David, from the stars to man, ever since the creation of Adam, employing the very same method and means which man, imitating the divine method, is beginning to use when he employs electricity to carry his message to a distant friend. Your teachers who gave you that knowledge are as wise as the prophets and as holy as the holiest saints in heaven.”

When I told her of Faraday’s vision, that all things extend to and exist in every spot of the universe at the same time and that, therefore, all things are in perpetual contact with each other, every star feeling, so to speak, the heart-beat of every other star and of every living thing, even of the tiniest little worm in the earth, she answered:

“Faraday’s science is that part of my religion which is described in the words addressed to God by King David:

“‘Whither shall I go from thy spirit? Or whither shall I flee from
thy presence?

“‘If I ascend up into heaven, thou art there: if I make my bed in
hell, behold, thou art there.’

God is everywhere, and where he is, there is every part of his creation.” Her religion taught her how to catch the spirit of science, and I was always certain that science can teach us how to catch the spirit of her religion.

IX

END OF STUDIES AT THE UNIVERSITY OF BERLIN

I confess that when I first arrived in Berlin I brought with me old prejudices, which were annoying, to say the least. The Teutonism in Prague, when I was a schoolboy there, had made lasting impressions upon my young mind; they were with me when I landed at Castle Garden. Early impressions are very persistent and cannot be obliterated by time alone. Christian’s father, the innkeeper of West Street, and his friends, the hardy Friesland sailors who taught me how to handle the paint-brush, drew me closer to the German heart, and I found it much less grasping than I thought it was. But the Frieslander of those days had no great love for the Prussian. Bilharz, the idealist of Cortlandt Street, gave me a more intimate knowledge of the German temper, and helped much to dispel many of my early prejudices. But Bilharz displayed decided dislike for the Prussians. The few German friends whom I had during my “greenhorn” days were southern Germans, and they did not appear to be very friendly to the idea of a united Germany under Prussian hegemony. These early experiences encouraged me in the belief that the Prussians were probably responsible for the Teutonism which I disliked. This belief was strengthened by Bismarck’s anti-Russian and anti-Serbian, but strongly pro-Austrian, policy at the treaty of Berlin in 1878. He protested, I knew, that he would not sacrifice the bones of a single Pomeranian grenadier for all the Balkans; but I did not believe him. Hence the uncomfortable feeling of being in an enemy country, when I first came to and settled down in Berlin.

The Teutonism of Prague, more than anything else, was responsible for it. Racial antipathy is one of the saddest of psychic derangements; and, although it is a repulsive product of modern nationalism, the world does less than nothing to get rid of its insidious poisons. European civilization is being destroyed by it. I suffered from its evil effects during the early days of my life in Berlin. Helmholtz, Koenig, and all the officers in the Physical Institute showed me every kindness and consideration, and that prevented me from turning around and speeding back to Cambridge as soon as the first breath of the atmosphere of Berlin gave me an acute attack of anti-Teutonism. My German landlady and her friends, as well as the German students I met in the lecture-rooms, struck no responsive chord in my heart, because it was out of tune with my surroundings. I remained a stranger in a cold, strange land. A young Scotch friend of mine, a graduate of the University of Glasgow, appeared on the scene, some time after I had become settled in Berlin. He kept his promise, given me at Arran, to join me in Berlin. He stayed at the university for one semester only and heard lectures on Roman law. He looked like a northern Apollo: tall and erect, the pink of youth radiating from his handsome face, and the locks of purest gold adorning a lofty brow, which made you believe that you were looking at a young Sir Walter Scott. His deep-blue eyes knew of no suspicions, and his heart had never been touched by the poison of racial antipathy. He loved the world and the world loved him. His knowledge of German was very poor, and yet everybody loved to talk to him. Even the stern Schutzman (policeman), stirred up to white heat by too noisy a rendering of American and Scotch college songs in the slumbering streets of Berlin, was as gentle as a dove when the blue-eyed young Scot stood in front of him and greeted him with a honey-hearted smile. My landlady, quite an aged person, as well as her young boarders, begged me to bring him to dinner as often as possible. “Yes, do bring him,” said a sarcastic young fräulein; “you look quite human and almost handsome when he is around.” There was much truth in what she said; the poison of racial antipathy did not operate in me when he was present. He made friends on every side among the German students, and when I saw how he warmed up to them and how they warmed up to him I began to thaw out myself. Helmholtz and dear little Koenig were the first persons in Berlin who helped me to forget that Europe was made up of different races who lived in eternal suspicion of each other. After that, following the example of my Scotch friend, I began to rid myself of the poisonous infection which I received from the Teutonism in Prague; but it was a slow process. Helmholtz’s address on Faraday was so warm and so generous to Faraday as well as to Maxwell, and so wonderfully just, that I began to question the justice of my anti-Teutonic prejudices.

The two volumes of Helmholtz’s addresses and public speeches which I enjoyed so much during that summer in my mother’s vineyard made me almost repentant. My mother knew of my anti-Teutonic sentiments and never approved of them. One day we drove to visit my younger sister, who lived about fifteen miles from Idvor. On the way we passed through a large village, Echka, having a mixed population of German, Rumanian, and Serb peasants. There was a striking contrast in the appearance of the houses, of the people, and of their methods of moving about in the pursuit of their daily work. The German peasants were far ahead of the Rumanians as well as of the Serbs. My mother called my attention to it, but I made no comment. Presently we passed the stately Roman Catholic church of the village, which looked like a cathedral. It was built, I was told, by the German peasants of Echka, and my mother told me that it was crowded on Sundays and holidays, and that the priest was a very learned and a very good man. When we passed the Orthodox church, which was quite small and insignificant-looking, my mother said: “Would you not feel ashamed if St. Sava came down to earth again and after seeing that splendid German church looked at this hut which is called the Orthodox church? But small as it is you will never find it filled except at some weddings or at memorial services for some departed rich person, when people expect much feasting.”

Again I made no comment, because I was opposed to “alien intruders” myself, as some people called the German colonists; and my mother looked disappointed. Just then we saw two peasant girls carrying river water in shining copper vessels. These vessels were suspended at the ends of a long flexible staff which was nicely balanced on the shoulder of each young carrier, so that one vessel was in front and one behind her. The first girl was a blonde with slippers on her feet; a simple dark-blue dress covered her youthful figure and displayed the successive phases of her rhythmical movement. It was synchronized with the swinging motion of the bright copper vessels, which moved up and down like a double pendulum, bending the flexible shaft around its point of support on the shoulder of the fair carrier. The copper vessels, although filled to the brim, did not spill a single drop of water; the perfect adjustment of the swinging motion of the carrier to that of the swinging shaft produced this admirable result. The girl, the staff, and the shining vessels stood in a beautiful harmonic relation to each other. They reminded one of the harmonics in a sweet musical chord. It was a beautiful sight, and I said so. My mother, noticing my sudden burst of enthusiasm, sounded a warning. “She is a German girl,” she said, “and she certainly is lovely. Her heart and soul are in her job. But if you find one like her in Berlin, remember your promise; you must marry an American girl if you wish to remain an American, which I know you do.”

She evidently had become a little alarmed at the thought that her praises of the Germans might cause my sentiments to swing too far the other way. The second water-carrier was a barefooted and gaudy-looking lassie, who stepped along any old way and marked her track with frequent splashes of water from the copper vessels. “She is a wild Rumanian,” exclaimed my mother; “she can dance like a Vila, but she hates her job of carrying water. You will never find one like her in Berlin. The Germans have no use for people who do not love their daily duties.” My mother was a great admirer of the thrifty and industrious German colonists in Banat, whom she always recommended as models to the peasants of Idvor. When she heard my praises of Helmholtz and my confession of racial antipathy to the Germans she put up many powerful arguments which were most convincing. They had a wonderful effect.

When I returned to Berlin from Idvor things looked more inviting, and my landlady remarked that I looked much more cheerful than I did a year before, when I arrived from Scotland. In another year, she suggested jokingly, I might look as cheerful as a real Prussian, particularly if I should succumb to the charms of a Prussian beauty. Remembering the promise that I had given to my mother about marrying an American girl, I said to my landlady: “Never! I have already pledged my word to one who is nearer to my heart than any Prussian beauty could ever be.” “Ach, Herr Pupin, you have changed most wonderfully,” exclaimed the landlady, and then she added in a whisper: “Just think of it! To get a confession on the first day of your return which I could not get before in nearly a year! I understand now why you were always so distant to the young ladies in my pensionat.” But the change of feeling, speeded up by my mother, and noticed by my landlady, was speeded up almost as effectively by another Serb.

A Bosnian Serb with the name of Nikola had a fine cigarette shop on Unter den Linden, the principal avenue of Berlin. It was within a stone’s throw from the Imperial palace, and the highest aristocracy of Berlin patronized it. He was a rough diamond, and would stand no nonsense from any prince or count. If they found fault with his famous Turkish cigarettes he did not hesitate to tell them to buy them somewhere else. But he prospered, he said, because these German aristocrats never resented straight talk from man to man. He laughed at me, when I mentioned to him my suspicions and antipathies; and begged me to pass with him, from time to time, an hour or so in his store, and watch his German customers. I did, and profited much. The Prussian aristocrats had no racial antipathy against a Serb, if their apparently genuine affection for Nikola had any meaning. Nikola never left them in any doubt as to his pride of being a Serb.

Half-way between Nikola’s store and the Imperial palace was an old chop-house, called Habel, dating from the time of Frederick the Great. Frederick’s generals always stopped there for a glass of wine, when they returned from an audience with the king. The custom persisted and was still in existence when I was a student in Berlin. Nikola often invited me to early luncheon at this chop-house, and there we saw the great generals and marshals of the German Empire, sitting around a long and separate table and taking a glass of wine after returning from the Imperial palace, from their daily audience with old Emperor William. It was a wonderful sight; those tall, broad-shouldered, deep-chested, brainy, and serious-minded Teuton warriors inspired tremendous respect. Nikola assured me that he knew many of them personally, they being his customers, and that as human beings they were as gentle as doves. “Many a time I called them down when they joked about my cigarettes, and they submitted without a murmur. Do you call that arrogance?” asked Nikola, throwing out his chest and trying to look as stern and as imposing as any of the generals present.

Once he took me to an avenue where Moltke used to walk and showed me the great field-marshal, who was then eighty-six years old, but still as straight as an arrow. “Did you ever see a more modest and thoughtful or a more spiritual-looking man anywhere?” asked Nikola, and I confessed that I had not. “Then stop your talk about Prussian pride!” exclaimed Nikola. On another occasion we walked to the park and he showed me Bismarck, riding on horseback, a friend and an adjutant accompanying him. Nikola saluted him and so did I, and Bismarck saluted back graciously. “Does he look like a brute, or like a fool who would try to convert by force all the Slavs into Germans?” asked Nikola, poking fun at my anti-Teutonic suspicions. “No,” said I, “I do not think he does; in fact, I think he looks very much like Helmholtz, except that there is much less spirituality in his face than in that of the great scientist.” “Helmholtz!” exclaimed Nikola, “even he would lose his saintly expression, if he had to carry the load of the whole empire upon his shoulders, the socialists on the top of his load pushing it one way, and the clericals at the bottom pushing it the other way.”

Nikola was born in Bosnia when the Turks ruled supreme, and hence he was not much of a scholar; but he was a careful listener, and always thought through his own head; his judgment was remarkable, I thought. He knew who’s who and what’s what in Berlin better than many a foreign diplomat there. He used to joke about it, saying that his knowledge was expected of him, because he was the next-door neighbor of the great Kaiser. The Serbs of Banat did not seriously dislike the German colonists there, nor did the colonists dislike them, and they delighted in speaking the Serb language. They called each other “komshiya,” neighbor. The Serbs, in general, use this word when they refer to a German in a friendly way. Nikola always referred to the great Kaiser as his “komshiya”; many of his customers knew that and enjoyed it hugely. They returned the compliment and often addressed Nikola with the Serbian word “komshiya.” “Come and see my komshiya,” said he one day to me, and there I stood for the first time in front of the Imperial palace and waited for the old emperor to show himself at the window. He did that almost every day about noontime when the guards marched by on their daily parade. Presenting arms and looking straight at the old emperor, they marched by like a single body animated by a single heart and a single soul, and they spanked the ground with their vigorous goose-step, the rhythmic strokes of which could be heard quite a distance away through the ringing cheers of the enthusiastic crowd. “Do you know what that means?” asked Nikola. I answered “No,” and he said: “It means that every German looks up to his fatherland for orders, and the perfect rhythm of that goose-step means that every German will obey these orders and finish on time any job for the good of the fatherland that may be assigned to him. It is the symbol of German unity.” That was Nikola’s unique interpretation; I never heard anybody else interpret it that way. But Nikola had a lively imagination and he evidently wished me to get a favorable interpretation of everything the Germans did.

Between my young Scotch friend, my mother, Nikola, and my professors in the Physical Institute, I soon forgot the unpleasant memories of the Teutonism in Prague, and Berlin no longer looked to me like a Thraenenthal, a valley of tears, as my old friend Bilharz in Cortlandt Street would have called it. I soon found myself enjoying warm personal friendships of German fellow students and of the professors, and it was a very fortunate thing; it was providential. Nothing but the love of God and the friendship of man can give that spiritual power which one needs in moments of great sorrow. One day in the beginning of winter, of that year, a letter arrived from my sister, telling me that my saintly mother was no longer among the living. I vowed on that day that her blessed memory should be perpetuated as far as an humble mortal like myself could do it. Twenty-seven years later the Serbian Academy of Sciences announced that the income of a foundation in memory of Olympiada Pupin would be expended annually to assist a goodly number of poor schoolboys in Old Serbia and Macedonia.

The vanishing of a life which is an essential part of one’s own life produces a mysterious shift of the direction of one’s mental and spiritual vision. Instead of searching for light which will illuminate the meaning of things in the external physical world, as the vision of young people usually does, it begins to search for light which will illuminate the meaning of what is going on in the internal world, the spiritual world of our soul. The question “What is Light?” was no longer the most important question of my thoughts after my mother’s death. The question “What is Life?” dominated for a long time my thoughts and feelings. I became introspective, and, being a somewhat temperamental person, like most Slavs, I might have lost my way forever in the labyrinth of all sorts of metaphysical structures of my own creation. Providence came to my rescue. Two American students with aspirations in science similar to mine joined the Physical Institute. One of them, a Harvard graduate, the late Arthur Gordon Webster, was the very distinguished professor of physics at Clark University; the other, a Johns Hopkins man, Joseph Sweetman Ames, is now the director of the physical laboratory at Johns Hopkins and a worthy successor to the famous Henry Augustus Rowland. Their truly American enthusiasm and directness prevented me from relapsing into the drowsy indefiniteness, sometimes called idealism, of a temperamental and sentimental Slav. They told me many wonderful tales of the higher endeavor in science at Harvard and at Johns Hopkins. The new Jefferson Physical Laboratory at Harvard was a wonder, according to Webster; and Ames never grew weary of extolling the beauties of Rowland’s wonderful researches in solar spectra, and I never grew weary of listening to them. At times, however, I wondered why these two men had ever come to Helmholtz when they were so well off at home. Ames wondered, too, and he returned to Rowland at the end of the year; but Webster stayed, although in my presence he never admitted unreservedly that the Physical Institute in Berlin was very much better than anything they had at Harvard. Webster’s and Ames’s testimony convinced me that the great movement in the United States for higher endeavor in science was making rapid progress; and I longed to finish up my studies in Berlin and return to the United States. After my mother’s death Europe attracted me much less.

* * * * *

A new physical science was attracting much attention in Germany at that time, the science of physical chemistry. Helmholtz was very much interested in it. I had read his latest papers on the subject and they reminded me of what I had seen in Maxwell’s book on heat about Willard Gibbs of Yale. I soon discovered that the alleged German fathers of the new science were anticipated by Gibbs by at least ten years. Remembering the charge of De Tocqueville that the American democracy had never done anything for abstract science, I made a careful note of my find. It was a clean-cut little discovery, I thought, and Helmholtz admitted it. He suggested even that I might find material in it for a research leading to a doctor dissertation. I embraced the suggestion and started an experimental research, at the same time studying the theories of Gibbs, Helmholtz, and other authorities, mostly German, on physical chemistry. The more one penetrates the depths of any problem the more he yields to the belief that this problem is the most important problem in the world. This happened to me; and the Faraday-Maxwell electromagnetic theory was shelved, temporarily, on account of my interest in physical chemistry, and particularly on account of the prospect of finding there a doctor dissertation, which I finally did.

At the end of the first semester and at Webster’s suggestion he and I, in the spring of 1887, went to Paris for a short visit. We wished to see what physical science was doing at the Sorbonne and at the Collège de France, and to compare the academic world of Paris with that of Berlin. We stayed there three weeks and learned quite a number of novel and interesting things. The architectural beauties of Paris as well as its art galleries and museums made a profound impression upon me. As a record of a magnificent old civilization Paris, I thought, was incomparably ahead of Berlin. The spirit of Laplace, La Grange, Fourier, Ampère, Arago, Fresnel, Foucault, and Fizeau was very much alive in the ancient halls of the Sorbonne and of the Collège de France. The background of a former glorious period of physical science in France was much more impressive in Paris than the corresponding background in Berlin. But for every one of the great savants in physical and mathematical sciences, who were active in Paris at the time of my visit, like Poincaré, Hermite, Darboux, Appel, Lippmann, one could name several in Berlin. And there was nobody in Paris who, in my opinion, could measure up to Helmholtz, Kirchhoff, and DuBois Reymond. There was no statesman there of Bismarck’s caliber, and no general like Moltke. I saw no warriors who looked like the magnificent fellows whom Nikola first exhibited to me at the long table in Habel’s. General Boulanger was very much in the limelight. I saw him at a great official reception, and I should have felt very sorry if the destiny of France had been intrusted to him. The physical and chemical laboratories were rather poorly equipped and compared unfavorably with the corresponding laboratories in Berlin. The draped statues in the Place de la Concorde, testifying to France’s grief for the loss of Alsace-Lorraine, completed the picture of Paris in my mind, which was anything but cheerful. France, I thought, had not yet recovered completely from her wounds of 1870-1871, and I felt sorry. Two years earlier I had passed through Paris on my way from Pornic to Idvor and had carried away a much more cheerful picture. But at that time my observations, covering barely two days, did not see much; and, besides, I did not know Berlin at that time and could make no comparisons. If Paris reflected the spirit of France and Berlin that of Germany, then France, I thought, was a falcon with broken wings and Germany was a young eagle that had just discovered the wonderful power of its pinions. The wonderful intellectual and physical vigor of the new empire impressed powerfully every foreign student at the University of Berlin when I was a student there. This gave me much food for thought and I searched for explanations.

There was one explanation which always appealed to me much on account of its simplicity. I heard it from a very learned German. This was his story: The German iron always contained phosphorus, including also the great deposits of iron which the Germans had found in Alsace-Lorraine. The only good iron that Germany had prior to 1880 was that in the Iron Chancellor. Hence, Germany could not build up a steel industry, and without it no great industrial development is possible in any country. A miracle happened; a young Englishman, a clerk in a London police court, made a discovery which was destined to give Germany its great steel industry. This was Sidney Gilchrist Thomas, who discovered the so-called “basic Bessemer” process. It made iron containing phosphorus easily available for the manufacture of iron and steel products. This started the modern steel industry of Germany in the early eighties. Many a street in the towns of the German steel districts was named in honor of Gilchrist Thomas. “This,” said my informant, “is the power which, as you express it, the young German eagle has discovered in its pinions.” I suspected that the object of his story might have been to discourage an opinion on my part that the remarkable vigor of Germany was derived from the weakness of France. Hence I looked up the data of his story, but I found them correct. Years ago I told this story to the late Andrew Carnegie, and he agreed with my German informant. To-day I am convinced that neither the great works of Krupp, nor the great German navy, nor many other things which have happened since my Berlin days, would have been possible without the start which was made with the aid of Gilchrist Thomas.

Another remarkable assertion from the same informant made a lasting impression. According to him, united Germany would not have endured very long, if it had not been for the rapid rise of the German steel industry and of other German industries which followed in its wake. The organization of Germany as an economic unit secured the organization of Germany as a political unit. He summed it up by saying that Bismarck and Moltke had raised the structure of the German Empire, but that Gilchrist Thomas had built a steel ring around it which prevented it from falling to pieces. He added then a corollary to this startling statement, and I repeat it here in the form of a question. If the scientific research of a young clerk in a London police court, who studied chemistry in a London evening school, could do so much for Germany, how much can one reasonably expect from the great research laboratories of the German universities and technical schools? This, according to my informant, had become a national question in Germany. This information reminded me that the great movement in Great Britain and in the United States for higher scientific research was also present in Germany, but in a much more advanced form. My informant called my attention to Werner von Siemens’s pioneer work in this German movement.

Ernst Werner von Siemens was at that time, next to Helmholtz, the most admired scientist in the German Empire. He was the head of a great electrical plant in the heart of Berlin, and was known everywhere to possess a splendid combination of talents in abstract science and engineering. Men of that type were quite rare in those days, and they are very rare even to-day. I heard a great deal about him in a course of lectures on electrical engineering which I attended at the Polytechnic School of Berlin. I saw him several times, when he called at the Physical Institute on his friend and relative by marriage, Excellenz von Helmholtz. His remarkable appearance made a strong impression upon me, and I longed to see his great plant, where all kinds of electrical things were made, from the finest electrical precision instruments to the largest types of dynamos and motors, many of them his own inventions. As a sign of special favor Helmholtz gave me a note of introduction to his distinguished friend, who received me graciously and gave me to an official who took me around the great electrical plant, the first that I had ever seen. The impression which it made upon my mind was certainly wonderful, but not more wonderful than the impression which the great personality of Siemens had made upon me. The more I learned about him the more I became convinced that no industrial organization ever had a presiding genius of greater attainments than Siemens. His attitude toward abstract science and its relation to the industries is best described by mentioning here a fact which is of great significance in the history of physical science. He founded in that year, 1887, the great Physical-Technical Institute, and presented it to the German nation; Helmholtz was its first president. The modern science of radiation rests upon a foundation first laid by Kirchhoff and greatly strengthened by additional experimental data obtained in this institute under the guidance of Helmholtz. Planck, the successor of Kirchhoff at the University of Berlin, already in office before I left Berlin, was undoubtedly inspired by these experiments when he formulated his great law of radiation which forms to-day the last word in the science of radiation, a great science which justly bears the mark “made in Germany,” just as the electromagnetic theory bears the mark “made in England.” The Physical-Technical Institute will always stand as a memorial to the man who preached in Germany the doctrine of the closest co-operation between abstract science and the industries. Germany adopted it first; the United States adopted it many years later. Helmholtz and Siemens always represented to me the highest symbol of this co-operation.

Bismarck and Moltke, Helmholtz and Siemens, were the great power which the young German eagle had discovered in his pinions; and he flew as he had never flown before, and his flight astonished me when I was a student in Berlin. He who wants to know the real Germany of the eighties should study the lives of Bismarck and Moltke, of Helmholtz and Siemens. They, I firmly believed at that time, were the leaders of the German constructive thought and action; they were the fathers of united Germany just as Washington and Hamilton, Franklin and Jefferson, were the fathers of this country. But would the spiritual influence of the fathers of united Germany produce a German Lincoln? I knew the historical background of the Declaration of Independence and also its historical foreground too well to answer this question in the affirmative. Extraordinary men can do extraordinary things, but the course of a nation’s destiny will always be guided not by transient efforts of one or even of several extraordinary men of a given period, but by the persistent power of the nation’s traditions.

My visit to Paris was to supply me with more knowledge of the academic world of France, and also with some fresh food for thought relating to my problem in physical chemistry, and it did in a measure. But the current of thought which was started by some of the strongest mental stimuli which I received in Paris had nothing to do with either physical chemistry or with academic France; it ran into German channels which I described above. These were the channels which ran through the minds of most university men in Germany, and in these channels every problem in art, science, and literature was viewed at that time from the standpoint of German economic and political unity. My German scientific friends, particularly those in eastern Prussia, where I spent the summer vacation of 1887, would rather discuss those problems than the problems in physical chemistry or in the electromagnetic theory. It took me some time after my return from Paris to get back completely to my research in physical chemistry. But no sooner had I gone back to it than the irresistible power of the current of big events, following each other in quick succession, took me away from it again. I shall describe them in their historical order, but only in so far as they are related to the main thread of my narrative.

* * * * *

One of the many sources of inspiration at the University of Berlin was the Physical Society which met once a month at the Physical Institute. The research students of the institute were admitted to these meetings, and one can imagine what an inspiration it was to them to see and to hear the scientists like Kirchhoff, the great mathematical physicist, DuBois Reymond, the great physiologist, Hoffman, the great chemist, and Helmholtz, the greatest of them all. I often imagined while attending these meetings and listening to the learned remarks of these scientific giants, that I was a lucky mortal who by some strange accident had found himself suddenly among the great heroes in Walhalla. Helmholtz usually presided, and his impressive physiognomy suggested a Wotan presiding at a gathering of the Teuton gods in Walhalla. Whenever I hear Wagner’s Walhalla motif I am reminded of those memorable scenes in the Physical Institute in Berlin, the scenes of victory of the immortal mind of man over mortal matter.

At one of those meetings, which took place toward the end of 1887, many scientific giants of the university were present and Helmholtz presided. There was an atmosphere of expectancy as if something unusual was going to happen. Helmholtz rose and looked more solemn than ever, but I noticed a light of triumph in his eyes; he looked like a Wotan gazing upon the completed form of heavenly Walhalla, and I felt intuitively that he was about to disclose an unusual announcement, and he did. Referring to Doctor Heinrich Hertz, a former pupil of his and at that time professor of physics at the Technical High School in Karlsruhe, Helmholtz solemnly announced that he would describe some remarkable experimental results which Hertz had obtained by means of very rapid electrical oscillations. He then described in his inimitable way a preliminary report which Hertz had sent him, pointing out, in a most lucid manner, the bearing of these experiments upon the Faraday-Maxwell electromagnetic theory, and affirming that these experiments furnished a complete experimental verification of that remarkable theory. Everybody present was thrilled, particularly when Helmholtz closed with a eulogy of his beloved pupil, Hertz, and with a congratulation to German science upon the good fortune of adding another “beautiful leaf to its laurel wreath.” That thrill soon reached the physicists in every physical laboratory in the world; and for a number of years after that memorable announcement most investigators in physics were busy repeating the beautiful Hertzian experiments. The radio of to-day is an offshoot of those experiments.

This is no place to go into a detailed description of what Hertz 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.