Mihajlo Pupin | Columbia University (original) (raw)

Mihajlo Pupin

Knowledge is the golden ladder over which we climb to heaven;
knowledge is the light which illuminates our path through this life
and leads to a future life of everlasting glory.
From Immigrant to Inventor, Michael Idvorsky Pupin

Michael (Mihajlo) Pupin was born on 9 October 1854 in Idvor. During that time a little village Idvor was a part of the Austrian Empire, district called Banat military border. Today Idvor is an integral part of Banat and the Republic of Serbia in the province of Vojvodina.
Mihajlo Pupin was a famous American scientist, inventor and professor of Serbian origin.
Early, like a little child, Michael Pupin showed his intellectual talents and his parents sent him to school, first in Panchevo (Pančevo), then in Prague. After the death of his father he left for America in 1874. In 1879 he was able to enroll in Columbia College. His intelectual tenacity became apparent very early on and his desire to progress. After completing college, in 1883, he continued his education at Cambridge until 1885. Eager for further improvement, as the first winner of Tindal scholarship, he went to Berlin, to learn by the side of Hermann von Helmholtz. Berlin was the epicenter of the experimental physics of that time. Michael Pupin received his doctorate in 1889.
Michael Pupin returned to New York, at Columbia College, where he and his colleague Francis Crocker founded the first chair of electrical engineering in the United States. Before returning to the United States, in 1888, he married Sarah Catherine Johnson (1859-1896), with whom he had a daughter Varvara (Barbara, 1889-1962). Since 1896 till 1929 Michael Pupin spent his entire working life at the Columbia College (Columbia University from 1896).
Michael Pupin was one of the founders of the American Physical Society in 1899 (APS was established on May 20th in Pupin’s laboratory at Columbia University). He was and one of the first members of the American Mathematical Society.
Michael Pupin was a member of the first council for the establishment of NACA (National Advisory Committee for Aeronautics, 1915), from which, later (in 1958), formed NASA (National Aeronautics and Space Administration).
Michael Pupin is a winner of the Pulitzer Prize in 1924 for his autobiography From Immigrant to Inventor. He has and 3 more books: Thermodynamics of Reversible Cycles in Gases and Saturated Vapors (1894), The New Reformation; from Physical to Spiritual Realities (1927), Romance of the Machine (1930).
He is a holder of 18 recognized honorary doctorates.
He got 7 valuable awards: Eliot Kresson Medal of Franklin Institute (1902), Herbert award of French academy (1916), Edison's medal of American Institute of Electrical Engineers (1919), Honorable medal of American Radio Institute (1924), Honorable medal of Institute of Social Sciences (1924), Prize George Washington from Western Association of Engineers (1928), Medal John Fritz from four American National Association Engineers Electromechanics (1931).
He got and 2 valuable medals: White eagle, first degree, from Kingdom of Yugoslavia (1929); White lion, first degree, from Czechoslovak Republic (1929).
Michael Pupin was a president of: AIEE (American Institute of Electrical Engineers, 1925-26), IRE (Institute of Radio Engineers, 1917), The New York Academy of Sciences (1916), President of American Association for the Advancement of Sciences (1925-26), University Club (1930-31).
He was a member of: the National Academy of Sciences (USA), the American Mathematical Society, the American Physical Society, the American Philosophical Society, the French Academy of Sciences, the Serbian Academy of Sciences, Honorary member of German Electrical Society, Honorary member of American Institute of Electrical Engineers.
Mihajlo Pupin had accepted 35 of the patent in the United States and 6 in United Kingdom, and including analogs in ten different countries accepted him 133 patents. It is famous for patents: Pupin coil, modulator frequencies and electric resonator. He found a quick way to record using X-ray, a few months after the announcement of the discovery of Roentgen X-ray and found a secondary H-beams.
The building of the Institute of Physics at Columbia University, which was built in 1927, still bears his name Pupin Hall. Mihajlo Pupin was the fouder of the first Laboratory of Physics which was also first one of that kind in America and at Columbia University bears the name Pupin Laboratory. In his honor the Columbia University named their most prestigious prizes award Pupin’ş award in 1958.
A small Lunar impact crater, in the eastern part of the Mare Imbrium, was named in his honor also.
Mihajlo Pupin died in New York City in 1935 and was interred at Woodlawn Cemetery, Bronx.
Supervisors: Dragoljub A. Cucich (Cucić)

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Papers by Mihajlo Pupin

The Electrical Age, 1900

The art of measuring- the capacity of a condenser has not yet reached that stage of perfection wh... more The art of measuring- the capacity of a condenser has not yet reached that stage of perfection which can be justly claimed for the resistance measurement. The prevailing method is the ballistic galvanometer method. Leakage and absorption can and often do introduce serious errors into this method. These errors can be reduced to any desirable limit by employing alternating currents of appropriate frequency.

The Electrical Age, 1896

When a currentis produced in a vacuum three phenomena are manifested - heat, fluorescence in the ... more When a currentis produced in a vacuum three phenomena are manifested - heat, fluorescence in the glass, and radiant energy; this is detected by a photographie film, some of the rays being cut off, and shadows shown on the film. This describes in a general way the Roentgen experiment.

Physical review, 1894

Mr. Tesla introduces his lecture about as follows:- In our study of the physical universe we find... more Mr. Tesla introduces his lecture about as follows:- In our study of the physical universe we find that our sense of sight is superior to all other senses, because it enables us to penetrate much deeper into the fathomless depths of Nature's mysterious activities. The activity by means of which Nature reveals herself to us through our organ of sight,
the activity which we call light, deserves our closest attention. What is light? It is an electromagnetic activity, according to most advanced views; hence the importance of investigating those forms of electromagnetic activities which approach the phenomena of light as near as experimental possibilities of the present day will permit.
The introduction might lead one to expect that Mr. Tesla intends to describe a novel class of high-frequency electrical oscillations for the purpose of illustrating and giving new evidence in favor of the electromagnetic theory of light. In that case one would perhaps feel somewhat disappointed to find that Mr. Tesla's experiments are simply Hertz's experiments in a modified form, a form by which it can be shown that in the first place the Hertzian oscillations enable us to transmit a considerable amount of energy along a single wire, and in the second place that novel vacuum tube effects can be produced by rapid alternations of the electromagnetic field.
But this feeling of disappointment, if it should occur at all, would be soon dispelled and quickly give way to a feeling of admiration for the patient work of an enthusiastic inventor who has brought all the ingenuity of his remarkable engineering skill to bear upon the problem before him, and that problem is contained in the question:--What immediate benefits can modern electrotechnics derive from Hertzian oscillations? This problem Mr. Tesla handles with extraordinary ability.
.

No. 232,183 GB Pattent Office, 1926

The invention relates to the amlifying and the recording or reproducing of electrical impulses tr... more The invention relates to the amlifying and the recording or reproducing of electrical impulses transmitted as signals and is especially adapted for use in amplifying signal impulses trasmitted over a cable in submarine telegraphy, which impulses are usually of positive and negative current values. It will hereinafter appear however that the apparatus which we employ in carrying out our invention may be used also for the recording of unindirectional signals.

No. 139,494 GB Patent Office, 1921

This invention relates to the amplification of feeble electrical forces such as are or may be pro... more This invention relates to the amplification of feeble electrical forces such as are or may be produced in the electrical reception of signals transmitted in the form of electrical waves or sound waves, and it consists of a stable multistep amplifier in wich aperiodic pilot conductors are employed to destroy reactions relation berween the various parts of the multistep amplifier with respect to the electrical potential variations produced by internal low frequency distrubances, but do not destroy it with respect to the electrical potential variations produced by waves of signalling frequency.

No. 16,529 GB Patent Office, 1903

This Invention is an improvement upon the loaded conductors illustrated and described in Letter P... more This Invention is an improvement upon the loaded conductors illustrated and described in Letter Patent granted to me on July 14th 1900, No. 12733.
The rules governing the calculation of wave lengths and for determining the attenution constant and the distribution of the coils are the same as are set forth in full in the said Letters Patent, and also in varoius printed publications, among which I will mention particulary my paper titled " Wave Transmission over Non-Uniform Cables and Long-Distance Air Lines"...

No. 13,205 GB Patent office, 1895

Second: When a condenser is inserted in a circuit carryng a simple harmonic current and the conde... more Second: When a condenser is inserted in a circuit carryng a simple harmonic current and the condenser is then shunted by means of a coil of adjustable selfinduction and of low resistence but containing little or preferably no iron then the current is this shunt circuit can be made many times as strong as the line circuit by adjusting the condenser capacity and the self-induction of the shunt circuit in such a way as a complex harmonic sound can be analysed by means of acoustical resonators.

No. 101,702 GB Patent Office, 1917

The invention relates to receiving wave conductors which are loaded with resistance in order to s... more The invention relates to receiving wave conductors which are loaded with resistance in order to screen them against the disturbing effects of electrical waves, and particularly those waves which have the character of electrical pulses of short duration, known in the art as "atmospherics" or "strays".

Engineering Magazine, 1901

Ten years ago, in the first number of this Magazine, Mr. Herbert Laws Webb forecast the possibili... more Ten years ago, in the first number of this Magazine, Mr. Herbert Laws Webb forecast the possibility of Transatlantic telephony. Dr. Pupin has just devised the effective means for accomplishing this end. It is a striking instance of success in tracing out a mechanical analogy in an allied field. It was well-known that vibrations travelled better in a dense medium than in a rare one. Sound carried better in water than in air; waves travelled
further on a hard, heavy cord than on a soft, slack one. But to work out the analogy correctly — to determine the means and manner of loading an electric cable with inductance so that it should correspond to the densified medium and gain increased capacity for transmitting electrical waves—was a signal work of genius. In this article Dr . Pupin gives a general outline of the theory and experiment and a brief concluding measure of its significance.— THE EDITOR

Scribner's magazine, 1927

I have a story to tell you and I hope that it will deliver to you a message from physical science... more I have a story to tell you and I hope that it will deliver to you a message from physical science which was delivered to me in the course of the last fifty years.
Fifty-two years ago I found my first employment in a factory in New York.
That was my first opportunity to learn how to manage a boiler-room and its engine, and I gladly took it. It gave me the first lesson which taught me that the fire under the boiler supplies the driving power to every machine in the factory in which I was employed. To an untutored Serbian immigrant who had never seen such things in his native village, that was
an awe-inspiring knowledge, and it thrilled me. It stirred my emotions and
my imagination, and I almost became a fire-worshipper.

The Electical World, 1895

The question has often been asked whether there is any difference between neutralization of self-... more The question has often been asked whether there is any difference between neutralization of self-induction by apacity and resonance. A similar question is invariably put by young students when they first attempt to grasp the distinction between consonance and resonance in the case of sound. Consonance means strengthening of sound emitted by a vibrating body by connecting this vibrating body to a sounding-board, as for instance, when a tuning fork is put upon a table. Resonance means equality of periods of vibrations, and therefore synchronization.

The Electrical World, 1893

Various considerations led me to the conclusion that Foucault current and hysteresis losses were ... more Various considerations led me to the conclusion that Foucault current and hysteresis losses were not the only causes of this remarkable diminution of the resonant rise due to the presence of iron.

The Electrical World, 1893

By working with high frequencies and small ohmic resistance any voltage within practical limits c... more By working with high frequencies and small ohmic resistance any voltage within practical limits can be obtained. Ohmic resistance, however, is not the only thing which limits the resonant rise of potential.

The Electrical World, 1893

5. Resonance in Circuits with an Impressed Complex Harmonic Electromotive Force. If the impressed... more 5. Resonance in Circuits with an Impressed Complex Harmonic Electromotive Force. If the impressed E. M. F. is a complex harmonic, then the circuit may be brought into resonance with any of the component harmonics. I have an apparatus here which is capable of producing E. M. Fs. of almost any complexity. I call it an electrodynamic current interrupter, for want of a better name...

The Electrical World, 1893

On the Determination of the Pitch of an Electrical Circuit . - If we wish to know the pitch of a ... more On the Determination of the Pitch of an Electrical Circuit . - If we wish to know the pitch of a musical instrument, say of a tuning fork, to choose a simple illustration, we simply give it an impulse, say a tap with the finger, and then listen to the vibrations, which, in general, will last for several minutes, and give us sufficient time to make up our minds as to what the vibrations sound like.

The Electrical World, 1893

A large part of the subject of the following discourse was discussed by me, but in a different wa... more A large part of the subject of the following discourse was discussed by me, but in a different way, in three papers.("American Journal of Science", April, May and June, 1893.) The method which I have adopted in the following discussion seemed preferable to the mathematical method which I followed in those papers. It is probably just as exact, and certainly a much clearer way of viewing the variable flow of electricity, especially
those features of it which have a more or less direct practical bearing.

Electricity, 1900

The art of measuring the capacity of a con denser has not yet reached that stage of perfection wh... more The art of measuring the capacity of a con denser has not yet reached that stage of perfection which can be justly claimed for the resistance measurement. The prevailing method is the ballistic galvanometer method. Leakage and absorption can and often do introduce serious errors into this method. These errors can be reduced to any desirable limit by employing alternating currents of appropriate frequency.

American Journal of Science, 1895

The law of electro-magnetic fiux is a short expression for the well-known quantitative relations ... more The law of electro-magnetic fiux is a short expression for the well-known quantitative relations between electromotive force and electric fiux on the one hand and magnetomotive force and magnetic finx on the other. Ohm's law is a part of it.
These relations are statements of experimental facts which we know to hold true for constant and slowly varying forces. The object of this investigation is to show the exact position which this law occupies in Maxwell's electro-magnetic theory; to point out its limitations; to show that Maxwell's electromagnetic theory of light demands a more general form of this law; and finally, to present a general form of this law of which
both its ordinary form and also those forms which were assumed hypothetically in some of the recent developments of the electro· magnetic theory of light are special cases.

Transactions of the AIEE, 1900

The art of measuring- the capacity of a condenser has not yet reached that stage of perfection wh... more The art of measuring- the capacity of a condenser has not yet reached that stage of perfection which can be justly claimed for the resistance measurement. The prevailing method is the ballistic galvanometer method. Leakage and absorption can and often do introduce serious
errors into this method. These errors can be reduced to any desirable limit by employing alternating currents of appropriate frequency.

American Journal of Science, 1895

The pump which forms the subject of the following description is a combination of two distinct fo... more The pump which forms the subject of the following description is a combination of two distinct forms of apparatus. First, a suction pump capable of raising mercury to practically any height, and second, an ordinary Sprengel pump.

The Electrical Age, 1900

The Electrical Age, 1896

Physical review, 1894

No. 232,183 GB Pattent Office, 1926

No. 139,494 GB Patent Office, 1921

No. 16,529 GB Patent Office, 1903

No. 13,205 GB Patent office, 1895

No. 101,702 GB Patent Office, 1917

Engineering Magazine, 1901

Scribner's magazine, 1927

The Electical World, 1895

The Electrical World, 1893

Electricity, 1900

American Journal of Science, 1895

Transactions of the AIEE, 1900

The art of measuring- the capacity of a condenser has not yet reached that stage of perfection wh... more The art of measuring- the capacity of a condenser has not yet reached that stage of perfection which can be justly claimed for the resistance measurement. The prevailing method is the ballistic galvanometer method. Leakage and absorption can and often do introduce serious
errors into this method. These errors can be reduced to any desirable limit by employing alternating currents of appropriate frequency.

American Journal of Science, 1895

Science, 1927

Philadelphia, Princeton and Menlo Park are the beginning, the middle, and the end of a tiny strip... more Philadelphia, Princeton and Menlo Park are the beginning, the middle, and the end of a tiny strip of territory which is the cradle of American history. No other spot in the vast territory of these United States reminds us of so many great historical events. No names of Americans remind us of so many great events in the history of American science as the following names: Benjamin Franklin, of Philadelphia, Joseph Henry, of Princeton, and Thomas Edison, of Menlo Park. Just as the achievements of the continental congresses in Philadelphia, and Washington's victories at Trenton and Princeton laid the foundation of these United States, so the scientific achievements of Franklin, of Joseph Henry and of Edison laid the foundation and added some of the superstructures of earlier American science.

Science, 1895

Propagation of Electrical Oscillations Through Air. - The velocity of propagation of electromagne... more Propagation of Electrical Oscillations Through Air. - The velocity of propagation of electromagnetic induction through dielectrics offered the first experimental test- of superiority of the Faraday-Maxwell theory over the older theories, According to these that velocity should be infinite; according to the Faraday-Maxwell view of electromagnetic phenomena it should be the same as that of light. Poincare reviews carefully all the
experimental evidences bearing upon this point. Hertz's experiments in Carlsruhe are first discussed and his early failures in arriving at a satisfactory result are pointed out.

Science, 1895

This work contains, briefly stated, a clear mathematical discussion of the general features of th... more This work contains, briefly stated, a clear mathematical discussion of the general features of the Faraday-Maxwell electromagnetic theory in Hertzian form, and of those special problems bearing upon this theory which are of particular interest to the experimentalist. The mathematical solution of these problems is compared carefully with the results obtained, principally by the experiments of Hertz and of other investigators who have extended the field of the Hertzian method of investigation. But it should be observed that the experiments of the pre-Hertzian epoch receive their full share of attention, as, for instance, the experiments of Rowland, Rontgen, and others. The work will undoubtedly exert a very strong influence upon the future develop- ments of the electromagnetic theory, and deserves, therefore, more than ordinary attention. This circumstance should, in the opinion of the reviewer, excuse the length of this review.

The realities described in the following seven narratives are the realities of human experience. ... more The realities described in the following seven narratives are the realities of human experience. They are not realities in the sense in which the word “reality” is often discussed by metaphysicists and speculative philosophers. Abstract philosophical discussions are foreign to the thoughts which guide these narratives.
The revelations of science during the last four hundred years succeeded each other like so many acts of a cosmic drama. Each act revealed a new physical reality which advanced man’s understanding of nature’s language, the language of the cosmic drama.

"Машинска цивилизација" је омиљени израз многих европских познатих писаца. Ови немају да кажу ниш... more "Машинска цивилизација" је омиљени израз многих европских познатих писаца. Ови немају да кажу ништа добро о њој.

Izvirno delo je izšlo pod naslovom "From Immigrant fo Inventor" leta 1923 v New Yorku (do leta 19... more Izvirno delo je izšlo pod naslovom "From Immigrant fo Inventor" leta 1923 v New Yorku (do leta 1930 je izšlo kar 17 izdaj); postalo je obvezno čtivo ameriških šol, avtor pa je prejel tudi znano Pulitzerjevo nagrado leta 1924; prevedeno je bilo v številne jezike, tudi v slovenščino leta 1930, s posebnim avtorjevim dovoljenjem: "Od pastirja do izumitelja": podnaslov: "s šestimi slikami" v dveh delih pri Vodnikovi družbi (Ljubljana 1931 in 1932).

ПРЕДГОВОР Када се осврнем и погледам како је ова књига нарасла за време од како је пишем — а на т... more ПРЕДГОВОР
Када се осврнем и погледам како је ова књига нарасла за време од како је пишем — а на то сам уложио преко годину дана - чини ми се да би се сврха њена најбоље описала овим речима у почетку Једанаесте Главе: "Главна сврха мога приповедања била је да опишем дивну појаву идеализма у американској науци, поглавито у природним наукама и у индустријама које су у вези с њима.
Својим сам очима посматрао како је дошао до те појаве и како се она постепено развијала. Све што сам до сада говорио, био је покушај да о томе дам ону сведоџбу коју може дати само стручњак, човек позван да о тим стварима говори. Али има много других американских научњака који су још више позвани да о овоме послу кажу свој суд; научњака чија је реч претежнија. Зашто, онда, да о идеализму у американској науци говори један научњак који је
свој живот овде почео као српски усељеник, крај толиких рођених американских научњака, који о том предмету знају много више него ја? Ко је довде пратио моја излагања, одговор на то питање наћи ће сам. Подвући ћу овде само ту околност, да извесни психолошки разлози поткрепљују моје мишљење: да има прилика које падају у очи усељенику, док умичу погледу синова неке земље. Ко види, тај и верује. Нека говори онај који има вере, само ако има неку испоруку."
Михајло Пупин

PREFACE NEW EDITION "From Immigrant to Inventor" has met with a reception which is certainly ... more PREFACE NEW EDITION
"From Immigrant to Inventor" has met with a reception which is certainly very gratifying. Evidently it conveyed a message which was timely. Hundreds of letters which I have received since the book was published, eighteen months ago, convince me that the message was particularly welcome to the youth of this country. It was intended for them, and I am certainly happy in the knowledge that it found in their hearts an enthusiastic response. Teachers of science and of religion have also assured me that they, too, found in the book a welcome
message, and urged that a less expensive edition of it be published, so as to reach a much wider circle of readers. This edition is a response to these earnest requests. I hope that the new readers of this less expensive edition will find in it just as welcome a message as the
readers of the older editions did.
Michael Pupin,
New York
August 1, 1925

FULL SYNOPSIS OF A TEN WEEKS' UNDERGRADUATE C0URSE OF LECTURES DELIVERED BY M. I. PUPIN, Ph.D., 1894

In this course on Theoretical Thermodynamics we shall limit our discussion to those features of t... more In this course on Theoretical Thermodynamics we shall limit our discussion to those features of the science which have a direct bearing upon the science of Caloric Engineering. The course forms, therefore, a theoretical introduction to the practical course on Heat Engines. It
seems desirable, however, to mould our discussion in such a way that it will serve at the same time the very important purpose of forming an introduction to the study of some of the best and most complete works on the subject. The work of K. Clausius {Die mechanische Warmetheorie) is and very probably will always remain the classical treatise on this very important branch of exact sciences. We shall, therefore, adopt the mathematical notation and follow as closely as practicable the method of discussion which is given in this great work of Clausius, who, as you will presently see, is one of the principal founders of the beautiful science of thermodynamics.

Die Aufgabe, die ich mir in der folgenden Untersuchung stellte, ist die folgende: Aus den Eigensc... more Die Aufgabe, die ich mir in der folgenden Untersuchung stellte, ist die folgende: Aus den Eigenschaften der thermodynamischen Funktion, die mein hochverehrter Lehrer, Herr Prof. v. Helmholtz, mit dem Namen „Freie Energie “ bezeichnet, einige auf Salzlösungen sich beziehende Sätze abzuleiten, die sich direkt vergleichen lassen, einerseits mit der Erfahrung, andererseits mit den R esultaten neuester theoretischer Untersuchungen, die auf einem von meiner Untersuchunsmethode verschiedenen Wege gefurt wurden.
Theoretische, mit der Erfahrung direkt vergleichbare, aus den heiden Hauptsatzen der Thermodynamik abgeleitete Schlussfolgerungen uber die Constitution der Salzlösungen sind nicht zahlreich. Dass sie für den besonders der Molekularphysik, von grösser Bedeutung sein können, das zeigen wohl zur Genüge die classischen Arbeiten von Kirchhoff, Gibbs und v. Helmholtz. W enn aber trotzdem die Constitution der Salzlösungen kein beliebtes Thema für den Theoretiker bildete, so mag dies wohl auf den Umstand zurückzuführen sein, dass für Salzlösungen die experimentelle Bestimmung gerade derjenigen physikalischen Grössen, auf die der Theoretiker am häufigsten angewiesen ist, bis jetzt noch ziemlich mangelhaft durchgeführt worden ist. Solche Grössen sind z. B. Dampfspannungsverminderungen, Verdünnungswärme, Verdampfungswärme, Compressibilität u. s. w. als Funktionen der die Salzlösungen vollkommen definirenden Parameter.
Zwei Gründe haben mich bewogen, mich an dieses Thema zu wagen: Erstens glaubte ich, dass man durch die Anwendung der physikalischen Grösse, die Prof. Pfeffer zuerst gründlich untersucht, sorgfältig gemessen und ihr den Namen „Osmotischer Druck“ gegeben hatte, vielleicht einen Schritt weiter in der Kenntniss der Constitution der Salzlösungen machen könnte. Zweitensschien mir die von Prof. v. Helmholtz angegebene Methode (1. c.) ein so zuverlässiger Wegweiser, dass unter ihrer Führung selbst einem weniger erfahrenen Theoretiker erlaubt sein würde, dieses noch ziemlich unbekannte Gebiet zu betreten. Eine unmittelbare Anregung zu diesem Thema gab mir mein hochverehrter Lehrer Herr Prof. Kundt, mit dem ich die neuesten, diesem
Thema verwandten Untersuchungen öfters einer kritischen Besprechung unterzog. Es sei mir erlaubt, ihm hier meinen verbindlichsten Dank auszusprechen.

The Electrical World, 1895

Sir: I feel very much flattered that Mr. Steinmetz has considered it worth his while to translate... more Sir: I feel very much flattered that Mr. Steinmetz has considered it worth his while to translate my article on ‘‘Electrical Consonance’’ into the language of electrographics. It gives me much satisfaction to know that Mr. Steinmetz has not detected a flaw in my reasoning and that the main features of this reasoning can be represented graphically by the extremely simple diagrams given by Mr. Steinmetz in the last issue of your esteemed journal...

Astronomy & Astro-Physics, 1893

Dear Sir: Your exceedingly interesting article "On the Photography of the Solar Corona without an... more Dear Sir: Your exceedingly interesting article "On the Photography of the Solar Corona without an Eclipse" encourages me in the belief that you and the readers of your esteemed journal may perhaps be interested in a method which I designed for the purpose of observing the distribution of the intense sources of ultra-violet light over the Sun's disc, and also of observing the solar corona without an eclipse.