Chronicle

IN THE COMMISSION ON THE HISTORY OF PHYSICAL AND MATHEMATICAL SCIENCES OF THE USSR ACADEMY OF SCIENCES

On April 12, 1948, in Leningrad, the regular thirty-fourth meeting of the Commission on the History of Physical and Mathematical Sciences was held under the chairmanship of Corresponding Member of the USSR Academy of Sciences T. P. Kravets.

The Commission heard reports by Professor A. V. Lebedinsky, “From the History of Physiological Optics,” and by Professor Ya. G. Dorfman, “Lomonosov and the Theory of Phlogiston and the Theory of Heat.”

In his report, Professor A. V. Lebedinsky examined the systems of ideas about the structure of the optical apparatus of the eye that had arisen in physiological science since the time of Hippocrates. In doing so he noted the great success of the Alexandrian school of physicians, who for the first time, on dissecting the eye, studied its structure. In the speaker’s opinion, Galen’s scheme, distorted by Celsus, deserves much attention. However, it was precisely the works of Celsus that exerted the greatest influence on the ideas of Arab physicians and physicists. Vesalius, in the sixteenth century, was the first to add some new data to what Galen had reported in his time.

The speaker then demonstrated ideas on the structure of the eyeball characteristic of Kepler, and dwelt in detail on Descartes’ works on physiological optics.

Professor Ya. G. Dorfman pointed out that the problems of heat, oxidation, and combustion constituted in the eighteenth century a peculiar knot in which questions of physics and chemistry, metallurgy, and energetics were intertwined. These problems attracted the attention of all the greatest scholars of that time. They also occupy one of the central places in Lomonosov’s works.

The speaker set himself the task of clarifying, as a result of the investigations he had carried out: 1) what Lomonosov’s factual achievements were in this field against the background of the science of his time, and 2) what influence his works had on world science.

An examination of Lomonosov’s work Reflections on the Cause of Heat and Cold, published in 1750, led the speaker to the conclusion that its main content is a devastating critique of the theories of caloric in physics and of fiery matter in chemistry. Lomonosov, with extraordinary brilliance, in the speaker’s opinion, revealed the internal inconsistency and contradictory nature of these theories. A study of the literature of that time allows Professor Dorfman to assert that, from the beginning of the eighteenth century up to 1766, not a single even modestly notable work appeared in Western Europe that subjected both, or at least one, of the theories of these imaginary substances to destructive criticism. Lomonosov’s work stands apart, and it exerted a serious influence on Western European science. The French chemist Macquer, who had defended the theory of caloric before the appearance of Lomonosov’s work, in his Chemical

“Dictionary,” published in 1766, went over to the positions of the kinetic theory of heat. But Macquer was unable to renounce the theory of fire in chemistry.

In the period 1773–1783 Lavoisier published a number of articles against fire matter in chemistry, supported by his own numerous experiments. Lavoisier used and developed, evidently by virtue of Lomonosov’s arguments. The speaker presented data proving that Lavoisier had read Lomonosov. Lavoisier and Laplace set forth the kinetic theory of heat in Lomonosov’s terms. However, in attacking the theory of fire matter in chemistry (the theory of phlogiston), Lavoisier was unable to renounce caloric in physics.

The English chemist Kirwan in 1783 and the outstanding Italian physicist Volta in 1786 noted “that extraordinary acuteness” with which “Mr. Lomonosov” in his time had refuted caloric. But Kirwan continued to remain a phlogistician.

Thus the greatest scientists of that epoch paid attention to Lomonosov’s work; they made use of his work, but none of them possessed sufficient boldness to reject both caloric in physics and fire matter in chemistry simultaneously.

Meanwhile Lomonosov, as is known, did not confine himself to theoretical investigations alone. Studying in 1775 the calcination of metals in sealed vessels, he, insofar as can be established from unpublished data, obtained a new weight argument against the theory of fire matter in chemistry. In his unpublished notes he also observes that he discovered new phenomena during the melting of metals in a vacuum. In this question Lomonosov, in the speaker’s opinion, was 20 years ahead of Lavoisier.

On the basis of all his experimental data, Lomonosov in 1756 created a new theory of the processes of combustion and oxidation. This theory was likewise not published by him in full, but it can be reconstructed from separate fragments. Lomonosov, paying tribute to the time, supposed that all bodies are complex and consist of elementary particles of sulfurous, mercurial, and acid (saline) matter, and also of particles of water, earth, and air. He mistakenly believed that the coloration of bodies determines which of these particles are located on the surface. Thus he came to the conclusion that in combustion or oxidation there occurs a change in the arrangement of the atoms of these elementary particles. This regrouping of atoms in the molecules of a substance, in Lomonosov’s opinion, is produced by fire through its heat, by means of particles of air or water vapor that adhere to the body and increase its weight.

In conclusion the speaker indicated that the theory created by Lomonosov, despite its erroneousness, was vivid and progressive. It was the first rough sketch of the future edifice of antiphlogistic chemistry, later created by Lavoisier. Lomonosov could not carry this step through to the end for the simple reason that in his epoch not only was the composition of the atmosphere still wholly unknown, but all gases were taken for the most ordinary air. Lavoisier’s discoveries became possible after the discoveries of carbon dioxide and hydrogen by Black and Cavendish. Thus Lomonosov was the first scientist consistently to reject both the matter of fire and the matter of heat. His devastating criticism of these imaginary substances played a great revolutionizing role in the history of world science.

On May 10, under the chairmanship of Corresponding Member of the Academy of Sciences of the USSR T. P. Kravets, the XXXV meeting of the Commission took place.

At the meeting, Academician V. I. Smirnov delivered reports: “On the Works of A. M. Lyapunov and Their Forthcoming Publication,” and Professor K. K. Baumgart, “Lomonosov on the Question of the Determination of the Goyescos Center of Swing.”

Academician V. I. Smirnov listed those materials that have been prepared for the collection of Lyapunov’s works in the “Classics of Science” edition. In addition, he briefly set forth the significance of Lyapunov’s works in the fol—

...ing areas: the stability of equilibrium and motion of mechanical systems with a finite number of degrees of freedom; the existence of figures of equilibrium (close to ellipsoids) of a rotating fluid whose particles mutually attract one another according to Newton’s law; the stability of figures of equilibrium of a rotating fluid.

Professor K. K. Baumgart, in his report, dwelt on the polemic that arose over the fourth part of Huygens’s book Horologium oscillatorium (The Pendulum Clock), published in Paris in 1673. This book is exceptionally rich in discoveries and inventions in the most diverse fields of knowledge.

The speaker listed 16 of Huygens’s most important discoveries and inventions, among which the central place is occupied by the solution of the question of the physical pendulum—the first case in history of solving a problem from the mechanics of a system of points.

No less important and interesting is the method by which Huygens solves his problem. At its basis he places the following hypothesis, which he regards, evidently, as an axiom: “A system of weighty bodies cannot, under the influence of the force of gravity, come into such a motion in which the center of gravity rises above its initial position.” From this Huygens directly derives his “fourth theorem,” which states: “If a physical pendulum completes part of its oscillation and, upon striking a plane, breaks up into separate weighty particles, and each particle rushes upward as far as it can with the speed it has acquired, then the center of gravity will rise to the same height as it had before the oscillation began.”

The very next theorem, the fifth, relying entirely on the fourth theorem, gives the correct length of the physical pendulum.

Thus, Huygens bases his conclusions on an “energetic” principle.

It is, of course, incorrect to assert that Huygens established the law of conservation of energy. Yet among the forerunners of this law he occupies an outstanding place. He always uses his “energetic” principle correctly. From it he derives the impossibility of perpetual motion and, conversely, refutes the erroneous assumptions of his opponents by showing that they lead to perpetuum mobile.

From the numerous passages in Huygens’s book, the speaker cites one quotation: “This hypothesis of mine is also suitable for fluids, and with its aid one can prove not only all the theorems concerning floating bodies, but also most of the other theorems of mechanics. If inventors of new machines, who strive in vain to construct perpetual motion, followed my hypothesis, they would easily understand their errors and would understand that their goal is wholly unattainable.”

Incidentally, the speaker pointed out an inaccuracy in N. N. Andreev’s article “Perpetual Motion” in the Great Soviet Encyclopedia, where Huygens is only conditionally indicated in the list of seventeenth-century scholars who opposed perpetuum mobile.

Huygens’s “energetic” considerations were alien to many of his contemporaries and provoked objections.

The book The Pendulum Clock was a success. Further, the speaker quoted Newton’s remarks about Huygens and, in particular, about the book The Pendulum Clock. However, eight years after the book’s publication a polemic arose. It is printed in Huygens’s works, edited by Gravesande; twelve documents are presented in all. The chief opponent was the Abbé Catelan, to whom six of the documents belong; two belong to Jacob Bernoulli, one to de l’Hospital, and three are Huygens’s reply.

Catelan points out that gravity does not act in the same way on free and constrained particles. In free particles, the velocities according to Gali...

... are proportional to the square roots of the heights of fall. In a coupled pendulum, the speed of the individual parts is necessarily proportional to the radii and, consequently, to the heights of fall.

To this is added the circumstance that the sum of the speeds of all the particles of a compound (physical) pendulum must, in Catelan’s opinion, be equal to the sum of those speeds which the individual particles of the pendulum would have if each represented a simple pendulum with the same point of suspension as the compound pendulum. In this assertion of Catelan, says Huygens, Descartes’ philosophy exerts its influence. On the basis of the foregoing, Abbé Catelan considers Huygens’ fourth theorem incorrect. The height of rise of the free particles cannot be such that the center of gravity should be at the same height as in the compound pendulum before the beginning of the oscillations.

Abbé Catelan proposes his own theorem for determining the position of the center of oscillation; namely: the period of a compound (physical) pendulum is the arithmetic mean of the periods of all its constituent particles, considered as simple pendulums with a common axis of rotation (point of suspension).

He also finds objections to Huygens’ construction of the cycloidal pendulum.

Bernoulli at first takes the side of Huygens against Catelan, but then tries to devise his own method for deriving the law of motion of a physical pendulum; namely, he finds that in a physical pendulum the particles closer to the axis of rotation are retarded by the more distant ones and, consequently, themselves accelerate the latter. He attempts to calculate this action for the case of a pendulum consisting of two weighty particles, and in doing so falls into contradiction with Huygens.

The error in Bernoulli’s calculation was pointed out by l’Hôpital, who confirms the correctness of Huygens’ conclusions.

Huygens, in three of his replies, refutes all of Catelan’s objections. He shows that both of Catelan’s propositions—on the sum of speeds and on the sum of periods—are incorrect and, moreover, contradict each other. Both lead to raising the center of gravity to a greater height than that from which it descended, and moreover both at different heights. Consequently, Abbé Catelan’s proposals lead to the construction of a perpetuum mobile. He also explains Catelan’s misunderstanding concerning the cycloidal pendulum. Huygens further indicates that he does not think it would be easy to prove his theorem by another method than the one he used. Only l’Hôpital succeeded in doing so for a very special case, whereas he managed to find a general solution.

Huygens further indicates that a compound pendulum loses in speed in the sense in which this concept is used by Catelan, but there is preserved the lifting force, which depends on the sum of the squares of the speeds and is preserved here and in other cases of mechanics. Here, too, the “energetic” note is heard.

The polemic ended, as was to be expected, with Huygens’ victory.

On 2 June, under the chairmanship of Academician S. I. Vavilov, the XXXVI meeting of the Commission took place.

Reports were heard by Academician L. S. Berg, “The Merits of E. H. Lenz in the Field of Physical Geography,” and by Professor A. A. Gershun, “Bouguer Photometry.”

“E. H. Lenz,” began L. S. Berg’s report, “was not only a famous physicist, especially in the field of electromagnetism, but also an outstanding physical geographer.”

Having recounted Lenz’s circumnavigation, made on the naval sloop Enterprise under the command of the famous circumnavigator O. E. Kotzebue, the speaker dwelt on two instruments made by Lenz jointly with E. I. Parrot and which created...

epoch in the history of oceanography: (1) the bathometer, an instrument for bringing up samples of water from the depths, and (2) the depth gauge, an instrument for measuring depths. With the aid of these two instruments Lenz made his observations of the specific gravities of the water of the Pacific Ocean at the surface and at depth. Regarding Admiral Makarov’s views on some of Lenz’s views, he wrote: “Lenz’s observations are not only the first in chronological order, but also the first in quality, and I place them above my own observations.”

Having next set forth the route of Lenz’s circumnavigation on the Predpriyatie, the speaker dwelt on the scientific results obtained by Lenz in the field of oceanography, and noted their absolute accuracy and correctness, confirmed by later scientific investigations.

Academician S. I. Vavilov, noting the remarkable experimental abilities of E. Kh. Lenz, whose observations, made in the first quarter of the nineteenth century, were so brilliantly confirmed by the later observations of Admiral Makarov, proposed that, when the Commission publishes Lenz’s works, a methodical review of the measurements made by Lenz be included.

A. A. Gershun noted that the current year marks the 250th anniversary of the birth of Pierre Bouguer. At the direction of S. I. Vavilov, the series “Classics of Science” has undertaken the publication of a translation of Bouguer’s optical treatise devoted to questions of photometry. This treatise sets forth the basic principles of visual photometry, describes methods of photometric measurements and the apparatus serving this purpose. The system of photometric knowledge constructed by Bouguer was applied by him to the consideration of a number of questions—physical, astronomical, and geophysical.

Bouguer is, in the true sense of the word, the creator of photometric science. He is also one of the founders of all optics, geodesy, gravimetry, hydrography, and the theory of the ship. It should be noted that his manual on navigation went through more editions in Russia than in France, and that famous Russian navigators of the eighteenth and early nineteenth centuries studied from it. Bouguer’s scientific legacy is very great and little studied, and the role assigned to him in the history of science is smaller than the one he deserved.

The speaker briefly presented Bouguer’s biography and, as examples illustrating his scientific activity, examined the question of Bouguer’s participation in the struggle for Newtonian views and compared the works of Bouguer, Euler, and Lambert on the dependence of brightness on the direction of radiation.

Academician S. I. Vavilov pointed out that the publication of Bouguer’s Photometry is absolutely necessary, because Bouguer is as remarkable a figure in this field as Kepler or Newton. Bouguer was the first to introduce the quantitative measurement of light. His treatise on this question is full of remarkable observations that have retained their significance in the field of optics to this day. Unfortunately, this treatise has been completely forgotten in the West, unless one counts a poor reprint with weak notes, issued 25 years ago and having had no success. Meanwhile, Bouguer’s treatise, in its character and style of exposition, is an extraordinarily modern book, which is read very easily and with great interest.

In conclusion, Academician S. I. Vavilov expressed the wish that Bouguer’s book Photometry should see the light of day as soon as possible, since this book is needed and deserves to be published in Russian.