REPORTS ON THE HISTORY OF PHYSICS AT THE SESSION OF THE ACADEMY OF SCIENCES OF THE USSR

The last session of the Academy of Sciences (January 5–11, 1949) was devoted to questions of the history of science. They were also reflected in the reports delivered in the Division of Physico-Mathematical Sciences, to which two meetings were devoted.

Reports on questions in the history of physics were presented by Prof. K. K. Baumgart, “The Work of E. Kh. Lenz and B. S. Jacobi in the Field of Electromagnetism”; Corresponding Member of the Academy of Sciences of the USSR M. A. Shatelen, “From the History of Metrology in Russia”; Prof. L. S. Pashentsev, “On the Works of B. S. Jacobi in This Field”; Prof. P. S. Pashentsev, “Russia—the Birthplace of the Electromagnetic Telegraph”; and Deputy Minister of the Electrical Industry D. P. Efremov, “Academician B. S. Jacobi—a Pioneer of Electrical Machine Building.”

After a brief survey of the state of the science of electricity by the 1830s, Prof. K. K. Baumgart noted that the task of his report was to elucidate the role of two Russian academicians—Emilii Khristianovich Lenz and Boris Semënovich Jacobi—in the establishment of the science of electricity and magnetism. Differing in their inclinations and in the character of their gifts, they worked in one and the same direction.

Lenz strove to replace qualitative observations with quantitative ones, verbose explanations with the formulation of laws in mathematical form, and in general sought to free himself from vague notions.

Lenz’s first work, reported by him to the Academy at the end of 1832, bears the title “On the Laws According to Which a Magnet Acts upon a Spiral, if It Is Brought Near to or Removed from It, and on the Most Advantageous Construction of a Spiral.” In this work Lenz considers the induced current as instantaneous and conducts his observations, using modern terminology, by the method of a ballistic galvanometer. A wire is wound on the armature of a magnet, the ends of which are connected with a sufficiently distant multiplier. The armature was torn away from the magnet and, with the aid of a mirror and scale, the deflection of the multiplier needle was observed. In this way Lenz observed the quantity of electricity that had flowed.

Lenz’s second work on electromagnetism (reported on November 29, 1833) concerns the determination of the direction of the induced current, or, as Lenz expresses it, of the galvanic current caused by electrodynamic distribution.

An important work of E. Kh. Lenz, “On the Properties of Magneto-Electric (i.e., Induction) Currents,” dates from 1840. This work is directed against the view, very widespread at that time, that galvanic currents of different origin (hydroelectric, thermoelectric, magnetoelectric) are different from one another. Some exert a predominantly chemical action, others a predominantly thermal one, still others a predominantly magnetic one, etc.

Lenz sharply rebels against these views, which “undermine the very foundation of science,” and by direct experiments and reasoning destroys the fictions of his opponents.

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E. Kh. Lenz’s remarkable investigations on the production of heat by the galvanic current were published in the form of two articles in 1843 and 1844.

At the beginning of the first article Lenz points out that he had been occupied with this question for a long time and was continuing his investigation. However, the appearance in print of Joule’s article, which had arrived at the same conclusions, compelled him to publish the results he had already obtained. He intended to continue his long-begun work further, all the more because he considered Joule’s experiments not free from objections; the same opinion was held by Academician Hess (the well-known thermochemist, the author of Hess’s law). What follows is a detailed analysis of the apparatus and method. Lenz used Nervander’s tangent galvanometer, which he carefully graduated by three independent methods (as a tangent galvanometer, as a sine galvanometer, and by comparison with a copper voltameter). Lenz confined himself to the case of metallic conductors, in order to avoid the polarization that is difficult to take into account.

Thus the law now known as Joule–Lenz’s law was established. In the thoroughness with which the method was developed and the investigation itself carried out, Lenz’s work surpasses Joule’s.

Lenz was always interested in the question of the practical applications of science, of the most advantageous use of physical phenomena. This is evident even from the titles of his works, as well as from the significance he attached to the construction of theory and to the elucidation of the action of magneto-electric machines. A substantial part of his speech “On the Practical Applications of Galvanism” (1839) and the article “On the Theory of Magnetic Machines” (1842) were devoted to magneto-electric machines; but particularly remarkable in this respect is the last series of Lenz’s works on electromagnetism (1848–1858), devoted to the question of the influence of the speed of rotation of a magneto-electric machine on the induction current generated by it. It was precisely in these works that the depth of Lenz’s analysis, his ability to penetrate into the essence of a phenomenon, was especially strikingly manifested. Lenz discovered and correctly explained the phenomenon of armature reaction—the fundamental phenomenon without which the operation of electrical machines is inconceivable.

All of Lenz’s experiments and conclusions, with a few insignificant exceptions, have retained their significance down to the present day. All of Lenz’s works on electricity are united into one harmonious whole, directed toward elucidating the fundamental, principled aspects of the phenomenon. In his works Lenz appears as a first-class experimenter, who carried out the first quantitative investigations of induction current, and as one of the chief founders of the doctrine of electricity and magnetism.

Turning to the works of B. S. Jacobi, the speaker pointed out that, an engineer by training, an inventor on a large scale, a man full of creative ideas, one of the pioneers and creators of modern electrical engineering, Boris Semyonovich Jacobi was at the same time a major physicist.

The significance of Jacobi’s investigations on the theory of magneto-electric machines lies in the elucidation of the energy balance of these machines, which Jacobi conceived very clearly, although he did not use energy terminology. This is evident from his formulation of certain laws, for example: “The maximum work of a magneto-electric machine is directly proportional to the square of the sum of all electromotive forces and inversely proportional to the sum of all resistances.” The energy character of this formulation is beyond doubt. Jacobi, as an engineer, thought in equivalents, as is clear, for example, from such expressions as: “one must spend more than half a pound of coal in order to obtain the same work as is done by 6½ pounds of coal.” Jacobi clearly understood that in his time not only galvanic cells but also magneto-electric machines could not compete with coal. This did not prevent him from working energetically in the field of electrical engineering in the consciousness that the future belonged to electricity. Jacobi’s works are imbued with fantastic hopes, placed by many on

electrical energy, and showed that the general laws of machines apply to electrical machines. Jacobi’s calculations were used by all electrical engineers for a long time.

Jacobi’s merit, like Lenz’s, is also a clear understanding of the significance of Ohm’s law and the proper use of it.

Jacobi showed the absence of the so-called closing spark, whose existence was asserted by many physicists, for example Moser. He built an accurate spark gauge (1838) and showed that, when a galvanic battery was connected to it and a wire stretched taut, up to a distance between the points of \(5\cdot 10^{-5}\) English inch no spark jumped.

Jacobi repeated, in a somewhat modified arrangement (1838), and confirmed Faraday’s well-known experiment revealing the extra-currents of closing and opening, which that same Moser had doubted.

Jacobi had the idea of a direct determination of the speed of propagation of electricity (1838). For this purpose he constructed a rotating contact which closed the circuit for a time less than \(\frac{1}{9000}\) of a second. The contact was to close a circuit 126,000 feet long (about 40 km). It is not known whether this project, set forth in a letter to Academician Fuss, was carried out. Apparently the intention was to use a telegraph wire (possibly St. Petersburg—Tsarskoe Selo).

In 1839 Jacobi observed a curious phenomenon on the powerful battery of 12 Wollaston elements available to him, with a plate area of 3 square feet, i.e. with negligible internal resistance. The battery had mercury contacts which were closed by metal brackets weighing 13 g. If the battery was short-circuited, the brackets flew off with a crack. This phenomenon, which was interpreted by many as blowing of the current by its own magnetic field, Lenz, in reporting Jacobi’s work at the Academy, explained, following Ampère, by the repulsion of successive current elements. Jacobi refuted Poggendorff’s assertion that, when current is passed through a metal wire surrounded by a conducting liquid, all the current flows along the wire without branching into the liquid. Jacobi took a nickel-silver wire 51 cm long and placed it in a solution of copper sulfate. Using Wheatstone’s arrangement, he not only refuted Poggendorff’s conclusion, but also showed the points of exit and entry of the current line into the nickel-silver wire. At the point where the current left, the nickel-silver wire turned black; at the point of entry, a copper deposit appeared.

Jacobi devised two different new galvanic cells, which was quite in the spirit of an epoch when almost every physicist was devising a scheme for a new cell.

Jacobi carried out an important study showing the imperfection of the gas voltameter, in which there occurs, to a certain extent, the reunion of hydrogen and oxygen under the catalytic action of platinum, and to a certain extent simply the dissolution of hydrogen and oxygen in the electrolyte. Jacobi recommended a copper, and later a silver, voltameter.

Jacobi was responsible for a number of improvements in instruments. In particular, his variable resistance should be noted: the “Jacobi agometer,” which played a major role in the first period of the emergence of electrical measurements. In the last years of his life he constructed a variable mercury resistance—a complex instrument allowing very accurate operation. The study of this instrument was carried out after Jacobi’s death by Orest Danilovich Khvolson, then an assistant to Academician Wild (later professor at Leningrad University and honorary academician).

Concluding his report, K. K. Baumgart noted that the enormous work and great achievements of Lenz and Jacobi brought them the greatest

respect and unlimited authority among the Russian scientific public. Wherever they worked, they rightly played a leading role.

“The development of scientific metrology in Russia,” said M. A. Chatelain, “is closely connected with the names of our scholars and academicians. Thanks to their labors Russian scientific metrology arose. To a considerable extent it was to their initiative that international metrological work owed its origin, work that led to an international agreement—the so-called ‘Metre Convention,’ which to this day guides the entire international metrological service.”

Of especially outstanding importance in this direction was the work of Academician B. S. Jacobi.

The extraordinary inconveniences experienced by all countries, even within themselves, from the enormous variety of measures used in them, differing both in names and often in magnitudes, though bearing the same name, had long called forth a desire to bring order into the situation.

In our country, in Russia, work on the establishment of measures began very long ago, but it was not conducted systematically, proceeding from case to case. By a series of decrees the government tried to introduce some order into the use of measures and weights, chiefly in commercial dealings; those who violated the established rules were threatened with severe punishments. Thus, in Peter I’s decree of 1700 it was said: “If anyone deals falsely by measure or weight..., then he shall return threefold, and in addition a monetary fine shall be imposed and bodily punishment shall be inflicted.” A certain order in the service of measures and weights in Russia began to be established only in 1835, after the issuance of the law “On the System of Russian Measures and Weights.” By this law, the sazhen, with subdivisions into feet and arshins, and the funt were recognized as the basic measures. For their preservation it was decreed “to establish a special building”; Academician Adolf Yakovlevich Kupfer was appointed scholarly custodian of the model measures and weights. From that time begins the direct participation of the Academy of Sciences in matters of Russian metrology, becoming especially significant in 1851, when the question arose of introducing uniformity in the systems of coins, measures, and weights already on an international scale. Academicians Kupfer, Lenz, Perevoshchikov, Ostrogradsky, Struve, Wild, and others took part in the work of establishing a single international system of measures, but especially active work during this period was carried on by Academician B. S. Jacobi.

The history of the metric system is well known. It is only necessary to emphasize the role played in its dissemination throughout the world by Russian scholars and, in particular, Boris Semyonovich Jacobi.

In 1867, during the World Exhibition in Paris, the French government organized a Committee of representatives of various countries to discuss the means of achieving unity of measures, weights, and coins. The Committee worked as three commissions, the first of which dealt with questions concerning the unity of measures and weights. The chairman of this Commission was the delegate from Russia, Academician Jacobi.

Jacobi prepared for a long time to work in the Committee and saw to it that, before his departure from Russia, a special meeting was convened of the heads of various government institutions “to discuss the subject—as Jacobi writes—from the national point of view.” At this meeting Jacobi, as he writes, heard and took note of comments on the considerable difficulties that would be encountered in our country when changing to the metric system of measures and weights. In striving to make the Committee’s labors as effective as possible, Jacobi, taking into account that the question of establishing a system of measures and weights common to all peoples had already been discussed many times from a theoretical point of view, proposed to the Paris Committee that it devote special attention to the practical side of the matter. His proposals were unanimously approved by the Committee and formed the basis of its work.

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Upon his return to Petersburg, Jacobi entered the Physico-Mathematical Department of the Academy of Sciences with a presentation on the need to organize international cooperation for the joint manufacture of standards. This proposal was examined by a commission and was adopted in the commission’s report. In concluding its report, the commission proposed:

1. That the Academy ask the minister of public education to petition the government to invite all states to send their delegates for the creation of an international commission, which would have to meet in one of the capitals chosen for that purpose, with the aim of organizing the manufacture of metric prototypes and of creating a unit of measurement that would be truly universal and international.

2. That Academician Jacobi be instructed to report, at a meeting of the British Association for the Advancement of Science, on the principles of the present resolution and on the need for the speedy universal recognition of the metric system by the scholars of all countries.

In this report Jacobi for the first time came out against defining the meter as a natural unit of length equal to one ten-millionth part of a quarter of the Paris meridian, convincingly demonstrating that the French archival meter was not equal to this value and that, with each subsequent measurement of the length of the meridian, different figures would be obtained. Jacobi proposed nevertheless to adopt this archival meter as the prototype, which in fact would be a conventionally accepted arbitrary unit of length. In justifying his proposal to accept the archival meter as the prototype, Jacobi writes: “It cannot be denied that the fiction embodied in the definition of the meter greatly helped its wide dissemination and made it easier for other nations to accept it. Indeed, the meter owes a considerable part of its prestige to an idea flattering to human pride—the possibility of relating the measurements that man makes daily to the dimensions of the terrestrial sphere on which he dwells.”

Proceeding from these considerations, Jacobi also proposes adopting as the prototype the archival meter determined by French geodetic measurements, without connecting it with the length of the meridian.

This proposal, adopted by our Academy of Sciences, was communicated to the Paris Academy, and it too accepted it unanimously.

After the adoption of the Metric Convention and the organization of the international Bureau of Weights and Measures, international metrological work proceeded along a different path. Russian scholars and academicians, in particular Mendeleev, continued their work in international metrology, but now in another direction. Russian scholars extended their initiative even in Soviet times, achieving the broadening of work on the preservation of standards and on standards of electrical and magnetic units.

In his report, Prof. D. S. Pashentsev, on the basis of documentary data and the study of museum exhibits, convincingly showed that the priority in the invention of the electromagnetic telegraph belongs to P. L. Schilling, whose work was continued by Acad. B. S. Jacobi, who introduced much that was new into electrical telegraphy, in particular by proposing the world’s first direct-printing apparatus.

Under conditions especially unfavorable for the scientific and practical activity of the pioneer D. S. Pashentsev emphasized the conditions of distrust toward everything Russian and of deference to foreigners then surrounding him; all the greater significance is acquired by the works of the Russian scholars P. L. Schilling and B. S. Jacobi in one of the greatest achievements of science—the creation of the electromagnetic telegraph and its practical application. Exclusively great theoretical and practical questions, which constituted the problem of the telegraph, found their solution in the works of P. L. Schilling and B. S. Jacobi.

The names of these remarkable Russian scientists are the pride of our country, which was the true homeland of the greatest conquest of science—the electromagnetic telegraph.

D. V. Efremov began his report by noting that, at the start of B. S. Jacobi’s research in the field of electromagnetism, the doctrine of electricity was still in the initial stage of development and had not yet been put to practical use.

Jacobi made his first communication on the motor he had invented in 1834 to the Paris Academy of Sciences. A detailed description of the machine and of the various experiments carried out with it was given by Jacobi in 1835, while he was a professor at the University of Dorpat (Yuriev).

The motor constructed by Jacobi was the first engineering work in the field of electric machines and could already receive practical application. In it, unlike other models constructed with reciprocating motion of the electromagnet core, which copied the kinematics of the steam engine, the principle of rotary motion was applied, with the direction of the current in the rotating armature switched by means of a special commutator.

On November 29, 1833, Acad. Emil Khristianovich Lenz, in a report to the St. Petersburg Academy of Sciences, discovered the principle of the reversibility of the processes of electromagnetic rotation and electromagnetic induction, and thereby generalized Faraday’s two discoveries. This generalization by Lenz was formulated as follows:

“If a metallic conductor moves in the vicinity of a galvanic current or a magnet, then a galvanic current is excited in it of such a direction that it could produce, if the given conductor were at rest, its displacement in the opposite direction, it being assumed that such displacement can take place only in the direction of motion or in the directly opposite direction.”

This generalization by Lenz was not understood or used by his contemporaries, and up to the middle of the nineteenth century the paths of development of electric generators and electric motors, which have a common electromagnetic essence, diverged as two independent directions. The electric motor developed along its own path and, in a great many designs, appeared as a machine with reciprocating motion, like a steam engine.

But B. S. Jacobi, experimenting with his first motor, already in 1834 established the applicability of this principle to the electric machine, that is, he approached the concrete idea of the reversibility of the electric machine. In his detailed report of 1834 he indicated:

“When set in rotation by the magnetizing force of the galvanic current, the machine is at the same time a unipolar apparatus consisting of moving magnets, and is capable of producing a magnetoelectric current in a direction opposite to the galvanic current.”

In this first remarkable work on the electric motor, Jacobi conducted a large number of careful experiments, which made it possible to clarify certain questions connected with the back electromotive force of the motor, with the influence of the geometry of the windings and the dimensions of the winding conductor on the operation of the machine and on the electrical resistance of the circuit; and also, by measuring with a galvanometer specially built for this purpose, he determined various characteristics of the operation of the machine and its technical-economic indicators.

In connection with the highly successful work on the electric motor, on June 28, 1837, at the Academy of Sciences in St. Petersburg, a commission was created, established to apply electromagnetic force to the movement of machines according to the method of Prof. Jacobi. Academicians Lenz, Ostrogradsky, Fuss, and Kupffer were brought into the work. In addition, Colonel So-

Bolevsky, Vice-Admiral Krusenstern, ship engineer Burachek, Lieutenant Zelenoi.

The commission, having satisfied itself that it was possible, with Jacobi’s motor, to set mechanisms in motion, came to the conclusion that all efforts should be directed toward the practical application of the new electric motor for propelling vessels.

This was the period when the old sailing fleet was being re-equipped with steam engines, and therefore the appearance of a new type of motor naturally interested the naval department; and already on September 13, 1838, an eight-oared bark with Jacobi’s motor mounted on it and with paddle wheels constructed by him made a voyage along the Neva.

Working in this direction, Jacobi made yet another remarkable proposal: the construction of a submarine driven by an electric motor powered by a galvanic battery. Thus, he was decades ahead of the principle of application he pointed out.

In these first schemes of Jacobi, the galvanic battery was the principal source of electrical energy. Therefore, while improving the motor, Jacobi was at the same time working to improve the galvanic battery. Just as in the field of research on the electric motor, so too in the field of improving and investigating the galvanic battery, Jacobi did considerably more than any of his contemporaries.

The investigation of the galvanic battery enabled Jacobi to make a discovery of the greatest importance—electroplating—which alone could have immortalized his name.

From 1839 Jacobi was compelled to curtail his investigations in the field of electric motors to a considerable extent.

On July 17, 1839, he received from Nicholas I, transmitted by the Minister of Education Uvarov, a new assignment—to begin work on the question of galvanic mines; and for the 16 best years of his life he devoted himself with enormous energy and great success to this matter, important for the defense of the state.

As a result of extensive research and engineering work, in 1849–1850 grandiose experiments were carried out near Kronstadt, between the forts Alexander and Risbank, on electric-mine barriers. The report on these experiments, written by Jacobi and reviewed at a meeting of the special committee on April 12, 1851, summed up an entire stage of fruitful and intensive work in which Jacobi’s engineering and scientific talents manifested themselves with particular force. The scale and results of these experiments can be compared only with experiments that were conducted a quarter of a century later in Scandinavia in 1874–1876.

Jacobi’s experiments in the field of electric-mine defense, as well as the results of the practical use of underwater mines in the Crimean War of 1854–1855, led to the creation of designs whose principles remained in use until the beginning of the twentieth century, while the details of these designs appeared abroad only 25–30 years after their creation.

Thanks to the labors of B. S. Jacobi, the Russian army and navy were far earlier than other armies prepared for the use of a new means of defense, and the Russian electric-miners trained and educated by him enjoyed well-deserved authority.

Jacobi’s work on strengthening the Baltic ports with electric-mine barriers using self-acting anchored mines is the first in world practice, standing for its time at an extraordinarily high level.

On a smaller scale and with significantly less technical perfection, electric-mine barriers were used in 1861–1865 in North America during the war between the Southern and Northern states. Almost until the end of the nineteenth century, the level of electrical mine technology differed little from what Jacobi had created.

Jacobi’s work “Galvanic and Electromagnetic Research,” published in 1847 in the Proceedings of the Academy of Sciences, is a classic work on electrical engineering and electrical machines at the initial stage of their development.

Nor can one fail to mention Jacobi’s work in developing insulated wires for electrical machines and apparatus, and underwater and underground cables for electric telegraphy and the transmission of electrical energy to supply a system of mine defense. Jacobi developed not only the designs of wires and cables, but also the technology for their mechanized production (insulating and winding machines). Jacobi’s underwater cables, laid in seawater, made it possible to transmit electrical energy over a distance of up to 12 km, and they worked quite reliably, providing the supply of energy from a central control post to groups of electric mine fuzes in mine barriers.

It is not without interest to note that the power-supply circuits for electric mine fuzes already contained the modern scheme for the distribution of electrical energy. From a central electric generator or galvanic battery, electrical energy was transmitted by underwater cable to a district underwater distribution point. From this district underwater distribution point, electrical energy was transmitted by parallel cables to individual groups of underwater mines.

Simultaneously with his scientific and engineering work in the most diverse fields of electrical engineering, B. S. Jacobi also carried out a large amount of work in training cadres of military electrical engineers. He first organized a training detachment in the Peter and Paul Fortress for the instruction of military ranks of the naval and land departments. Practical classes in electrical engineering and electric-mine work were held with the students, and galvanic lectures were read to them.

In February 1849 B. S. Jacobi organized the reading of lectures on galvanism and electromagnetism in the “upper” (senior) classes of the Main Engineering School. Jacobi delivered them according to a program that was very broad for its time. These lectures were the first applied course in electrical engineering not only in Russia, but also in Europe.

Jacobi’s pedagogical work, which instilled electrical-engineering knowledge among military ranks, contributed very greatly to the success of the cause and created the foundation on the basis of which Russian military electrical engineering could successfully develop.

It is difficult to overestimate the significance of B. S. Jacobi’s activity for the development of Russian science. This pioneer of electromachine building, the first electrical engineer, an outstanding scientist and remarkable teacher, harmoniously combined in his work profound scientific research with concrete practical engineering activity. He showed how much science can contribute to the solution of engineering problems if the tasks set before it are concrete and purposeful.

Russia was the first to put electricity to practical use in the most diverse fields.

The great Lenin proclaimed electrification to be the principal task of Soviet power.

And Soviet scientists and engineers, continuing the glorious traditions of their outstanding predecessors, who worked amid the backwardness and incomprehension of the ruling elite of tsarist Russia, are honorably carrying out the grandiose plans for the transformation of their country.

M. Radovsky