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.
[Illustration: THE HERTZIAN OSCILLATOR]
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: