Torichan Pavlovich Kravets

G. P. Faerman

On May 21, 1955, in the 80th year of his life, Torichan Pavlovich Kravets passed away. In him Soviet physics lost one of its most versatile and outstanding figures of the older generation.

T. P. Kravets was born on March 22, 1876, in the village of Volkovo, Bogoroditsk district, Tula province, into the family of a zemstvo physician. After graduating in 1894 from the Tula gymnasium, he entered the Faculty of Physics and Mathematics of Moscow University. As a student, he attended lectures by such outstanding scholars as A. G. Stoletov, N. A. Umov, N. E. Zhukovsky, N. D. Zelinsky, and others. But his true teacher, who exerted the deepest influence on T. P.’s entire subsequent life, was Pyotr Nikolaevich Lebedev. T. P. came to his laboratory as a third-year student and maintained an unbroken and firm connection with it until the very death of P. N. Lebedev.

It was not only the brilliant and original talent of the remarkable scientist and teacher that captivated Torichan Pavlovich. The colorful personality of this interesting man made a deep impression on his young pupil, one that remained for life. T. P. Kravets was not simply one of P. N. Lebedev’s pupils. Throughout his life he preserved that distinctive and unrepeatable creative unity of thoughts, aspirations, and efforts of teacher and pupil which is contained in the words “scientific school.” The methods of scientific thought, the manner of posing and experimentally developing problems, views on science and the principles of scientific work, the methods of educating pupils, the principles and technique of organizing the work of a laboratory and its collective—characteristic of T. P. Kravets—were to a considerable extent drawn from the Lebedev source. It was enough to hear T. P. speak even once about Lebedev and his laboratory to understand how deeply he respected and highly valued his teacher, how vivid the image of this man remained in his memory, and what a faithful and devoted pupil of Lebedev T. P. remained.

significance. This work was published in the little-distributed Proceedings of the Moscow Engineering School (part II, no. 6, 1912). Therefore, it is likely that Ladenburg in 1914 and Chako in 1931 repeated the results of T. P. Kravets, but without reference to his priority. While studying questions of the coloration of dye solutions, T. P. Kravets became interested in the origin of the coloration of colloidal solutions of metals. These works proved to be a prerequisite that made possible the subsequent emergence of T. P. Kravets’s outstanding work in the field of the physics of the latent photographic image.

In 1911 T. P. Kravets passed his master’s examinations, and in 1913 successfully defended his master’s dissertation in the Council of Petersburg University. His opponents were I. I. Borgman, N. A. Bulgakov, and D. S. Rozhdestvenskii. With the last of these, from that time on T. P. established friendly relations that lasted throughout their lives, until the death of D. S. Rozhdestvenskii.

At the end of 1913 T. P. Kravets was elected professor of physics at Kharkov University. With his move to Kharkov in the spring of 1914, a new period began in T. P.’s life. This period, it seemed, promised to be even more fruitful and successful than the preceding one. T. P. Kravets was then 38 years old. He was in the full bloom of his powers and talent. He already had a name in Russian physics as the author of an outstanding scientific work. A brilliant lecturer and teacher, he enjoyed wide popularity and affection among the students. A capable organizer, thanks to his personal qualities he quickly gained respect and trust among his colleagues, which was expressed in his election first as secretary of the faculty, and soon after as prorector of the university. T. P. came to Kharkov with broad plans for organizing a new physics institute, developing an independent scientific direction, perhaps a school, and energetically began to carry them out. The outbreak of the First World War shattered all these plans.

T. P. Kravets worked in Kharkov for six years. In 1921 he returned to Moscow, to his native Institute of Railway Communications, but now as head of the department of physics. In 1923 he became professor of physics at the new Irkutsk University. Here for the first time a group of young students began to form around him (V. N. Solov’ev, I. A. Parfianovich, V. P. Dubov, A. S. Toporets, and others). In Irkutsk, in the newly established university, T. P. did not have the conditions necessary for experimental work in his specialty—optics. Therefore T. P. sought and found application for his profound knowledge of the theory of oscillations in a field completely new to him—geophysics. Heading the Seismic Station of the Academy of Sciences on Lake Baikal, he began to enga-

were engaged in studies of oscillations of the water level in Lake Baikal, arising as a result of tides and seiches, i.e., the natural oscillations of the water mass caused by the action of winds. The geophysical work of T. P. Kravets and his students, carried out by methods of harmonic analysis of limnograms and by comparing the results with data obtained from experiments with models of reservoirs reduced to a definite scale, led to a number of discoveries. Thus, a tidal wave was discovered in Baikal and the amplitude of its oscillations was determined. It was found, for example, that Baikal’s seiche waves are transmitted along the Angara for distances of up to 40 km. These works were continued also in Leningrad, to which T. P. Kravets moved in the summer of 1926 at the invitation of the vice-president of the Academy of Sciences, V. A. Steklov, as head of the physics department of the Physico-Mathematical Institute of the Academy of Sciences (now the Physico-Technical Institute of the Academy of Sciences). Here these works were devoted to oscillations of the water in the Baltic Sea and to their connection with floods at the mouth of the Neva.

With the move to Leningrad there began the most fruitful and significant period in the life of T. P. Kravets, connected with his work at the State Optical Institute.

In October 1926 T. P. Kravets accepted D. S. Rozhdestvensky’s invitation to head the newly organized photographic department of the State Optical Institute. Here the exceptional abilities of T. P. as a scientist, teacher, and organizer of the work of a scientific collective unfolded in full force. The activity of T. P. Kravets in this period played an exceptional role in the development of scientific photography in our country and will remain forever in the history of Soviet science.

Before entering the Optical Institute, T. P. had never engaged in applied physics. The traditions of the scientific school to which he belonged, the external circumstances of his previous work, his personal scientific interests, and his scientific experience were very far from applied, technical questions. Of photography T. P. probably knew little more than an ordinary cultured amateur photographer or a physicist who uses photography as an auxiliary means of research. And so, having taken up what seemed to be an entirely alien matter to him, T. P. Kravets in a short time created a laboratory and assembled a friendly and fruitfully working group of young collaborators. He skillfully directed the activity of this group toward solving the most important problems of the theory of photography, such as the theory of the latent image, the theory of development, the theory of the synthesis of photographic emulsions, sensitometry of photographic layers (general and spectral), color photography and cinematography, precise photography, and others. The works carried out by the laboratory staff in all these fields soon placed it among the largest centers of this branch of science not only in the Soviet Union, but also beyond its borders. Personally

T. P. Kravets undertook research and achieved major success in the most difficult and most fundamental question of photography as a science: the question of the nature of the latent photographic image. This “transformation” surprised and astonished everyone who had known T. P. well. Thus, for example, S. I. Vavilov, once recalling T. P. Kravets as one of the participants in the “Lebedev colloquia,” said that of all the participants in these famous “colloquia” T. P. had been the most vivid representative of “pure” physics, had mastered theory better than many others, and was interested in the most fundamental and advanced directions of physical work of that time. And he immediately added that at that time he would never have believed that this same T. P. Kravets would in time become one of the leading workers in Soviet applied physics.

What caused this “transformation,” and what accounted for it?

Of course, the most powerful influence on T. P. was exerted by the general upsurge and the practical orientation of the creative forces of our people and of the best representatives of its intelligentsia during the period of the beginning of industrialization and the first five-year plans. T. P. Kravets was a patriot in the very best sense of the word. Aware of the technical and economic backwardness inherited from tsarist Russia, deeply understanding the importance of educational and cultural work and the role of science in the life of modern society, loving science and his country, he, by virtue of his lively and active temperament, could not remain aloof from this mighty movement. Perhaps not always fully consciously, but quite sincerely and with enthusiasm, he joined the ranks of that part of the pre-revolutionary intelligentsia which became an assistant of Soviet power and of the Communist Party in the cause of the technical re-equipment of our country, in the work of training new Soviet scientific and technical cadres.

A special influence in this direction was exerted on T. P. by Dmitrii Sergeevich Rozhdestvenskii. D. S. Rozhdestvenskii was characterized to a high degree by a state-minded approach to the evaluation of things and phenomena; he was marked by a revolutionary and socialist type of thinking, both social and scientific-technical. He was an enthusiast of the idea of uniting the most abstract science with the most concrete practice, and he tried to put this idea into practice in the State Optical Institute that he had created. Torichan Pavlovich deeply respected D. S. Rozhdestvenskii as a person and a scientist. They were friends. It is therefore not surprising that D. S. Rozhdestvenskii’s enthusiasm and ideas also carried away T. P. The task set before him by D. S. Rozhdestvenskii was to create, within the State Optical Institute, a laboratory that could play, with respect to the nascent photochemical industry,

...ness the same role that the GOI chemical laboratory played in establishing the production of optical glass in the USSR. This lofty goal, the general character of the work of the Optical Institute of that time, and the new opportunities for scientific and scientific-organizational work, never before available to him, carried away and captivated Torichan Pavlovich. He became an enthusiast and patriot of the GOI, one of D. S. Rozhdestvensky’s closest assistants in building the Institute. T. P. Kravets himself formulated his attitude toward the GOI, saying more than once that his best dream was to remain, to the end of his days, a staff member of the Optical Institute. Indeed, from 1926 until the day of his death his connection with the GOI was never broken.

Setting about the task entrusted to him and acquainting himself with a field new to him—scientific photography—T. P. turned his attention to a question which, naturally, had to attract the attention of a physicist-optician: the question of the nature of the latent photographic image. For almost a hundred years this question had remained a riddle that many outstanding investigators had been unable to solve. Here T. P. was aided by his experience in the optics of colloidal systems, his wide-ranging erudition, and his characteristic ability to grasp and single out the essential in a phenomenon, to formulate clearly the problem to be solved, and to view it from a general physical standpoint. He drew attention to the phenomenon of photochemical coloration of rock-salt crystals when they are irradiated with ultraviolet and X-rays, and he was able intuitively to perceive the connection between this phenomenon and the phenomenon of the formation of the latent photographic image. M. V. Savostyanova, at the Physicochemical Institute of the Academy of Sciences, undertook a special study of the nature of the coloration of rock salt. She proved that the coloring centers are colloidal particles of metallic sodium formed as a result of photolysis of the salt crystals. T. P. Kravets then (in December 1928) put forward the supposition that the formation of the latent photographic image proceeds in the same way, and that it is nothing other than colloidal particles of silver formed in the silver halide crystals of the photographic emulsion as a result of their photochemical decomposition by rays of the visible region of the spectrum. Through the work of T. P.’s pupils—M. V. Savostyanova, S. V. Cherdyntsev, A. S. Toporets, P. V. Meiklyar, and others—the correctness of this supposition was subsequently proved.

Thus the beginning of the activity of the new laboratory was marked by a major scientific success. In a short time T. P. Kravets gathered around himself a group of young co-workers (K. S. Lyalikov, G. P. Faerman, Yu. N. Gorokhovsky, S. V. Cherdyntsev, A. S. Toporets, A. T. Ashcheulov, and others) and set before each of them major scientific tasks in various fields of scientific photography.

Here T. P. Kravets’s talent as a scientific organizer manifested itself with particular brilliance. At the basis of T. P.’s “organizational style” (if one may put it that way) lay the ability to choose collaborators and to direct their work, stimulating in every way their own creative capacities. In selecting collaborators, T. P. was always aided by his clear mind, his great worldly and scientific experience, and his deeply honest and principled attitude toward science, toward the interests of the work, and toward the obligations he had assumed. I cannot recall a single instance in which anyone entered T. P.’s laboratory through patronage, acquaintance, or any other motives of a non-business character. At the same time, when accepting a new collaborator into the laboratory, T. P. not only spoke with him thoroughly and repeatedly, but also gathered information about the candidate’s professional qualities from his teachers or former supervisors and colleagues, striving to form for himself as complete and objective an idea as possible of the new collaborator and his abilities.

The most important pedagogical device of Torichan Pavlovich was the ability to show a young collaborator that he trusted him completely, that he did not doubt his strength and capabilities, or his unconditional ability to cope successfully with the assigned task. At the same time he carefully attended to the pupil’s work, showing a lively interest in it, an unfailing readiness and ability to help the work in a timely and tactful manner, as if unobtrusively, not imposing his opinion by force, but also not shrinking from the most direct and strict criticism. These critical remarks were always expressed in a benevolent and objective tone and therefore did not offend and were received with gratitude. In all T. P.’s long life there was not a single case in which he would have put his name on a pupil’s work, even if the work was carried out on a topic assigned by him and with his own closest participation.

A vast erudition and a lively interest in various branches of physics, thorough knowledge in adjacent fields of science—mathematics, astronomy, chemistry—a broad scientific outlook and great scientific experience made T. P. Kravets a valuable leader even in those fields where, it would seem, he could not be one. His collaborators—chemists, technicians, photographers, and others—will never forget what significance for their work the possibility of telling T. P. Kravets about it had, and how much his comments and considerations gave them.

With great gentleness and benevolence, T. P. was truly demanding. Scientific carelessness, bad faith, and a dishonest attitude toward work in T. P.’s laboratory were unthinkable. He knew how to create and maintain an exceptionally high moral level in the collective he directed and good relations among its members. He sincerely and selflessly loved young people, and, sensing this, they in turn always treated him with respect and love.

These qualities of organizer and scientific leader enabled T. P. Kravets to cope with the most difficult task he had undertaken and to create a major scientific school, now successfully working in the most important fields of scientific photography, even in those in which T. P. did not work personally. The creation of this school is the most important achievement of T. P.’s life.

T. P. Kravets remained head of the Laboratory of Scientific Photography of the State Optical Institute until 1938, when he moved to take charge of the Department of General Physics at Leningrad State University. At the same time, however, he remained a consultant to the laboratory and continued to participate in its work until the last days of his life.

T. P. Kravets’s department at LSU was the largest and most difficult department of the Faculty of Physics, since it served practically the entire university. Here T. P. not only succeeded in organizing and uniting a large collective that was new to him, but also began a series of scientific works, unfortunately interrupted at the beginning of the Great Patriotic War. During the evacuation of the University, T. P. remained in Leningrad as the authorized representative for the Faculty of Physics. His activity during the blockade of Leningrad revealed with full force the exceptional personal qualities of T. P. In an environment of shelling and bombing, hunger and cold, surrounded by people weakened and dying from exhaustion and hunger, himself ill and exhausted, the 66-year-old Torichan Pavlovich found within himself the strength not only to go to the Physical and Optical Institutes, to help the work of their staff members and to see to the preservation of the property left in his care, but also, with a joke, a cheerful story and, above all, by personal example, to raise their spirits.

In the spring of 1942 T. P. Kravets was evacuated from Leningrad and, after recovering somewhat, again began working at the State Optical Institute, which was then in evacuation. In 1943 T. P. Kravets was elected a corresponding member of the Academy of Sciences of the USSR. In 1945, after the State Optical Institute returned from evacuation, T. P. Kravets set about organizing in it a new laboratory for the study of the optical properties and the nature of the coloration of chemical compounds. In 1946, for his work in creating methods and instruments for photographic sensitometry, T. P. Kravets, together with a group of collaborators, was awarded the Stalin Prize, second class. He was also awarded the Orders of Lenin, of the Red Banner of Labor, of the Red Star, the Badge of Honor, and medals.

In the postwar years T. P. Kravets began to devote himself intensively to the history of physics. He became deputy to S. I. Vavilov in the post of chairman of the Commission of the Academy of Sciences of the USSR on the History of the Physical and Mathematical Sciences, took part in the publication of the works of D. I. Mendeleev, edited a new edition of the works of M. V. Lomonosov, edited the edition of the works of E. Kh. Lenz and wrote a commentary to it, translated the works of Faraday (the books of Lorentz, Drude, Abraham-Becker, and others).

were translated by T. P. in the prewar years), he finished editing an edition of the correspondence of the inventors of photography, Daguerre and Niépce, wrote a number of articles on various questions in the history of physics, worked in the Archive of the Academy of Sciences of the USSR, and so on. He did all this with his characteristic enthusiasm, ardent interest in the work, and great breadth. In this historical-literary work of his, the enormous range of T. P.’s knowledge and interests in the history of culture in general and the history of physics in particular is revealed with especial clarity.

Any account of T. P. Kravets would be incomplete without mention of his public activity. The public “vein” in him was very strong. From his younger years he took an active part in the work of various Moscow, and later Kharkov, scientific and educational societies. He organized and for many years was chairman of the Leningrad branch of the Scientific-Technical Society of the Photo-Cinema Industry, which under his leadership developed vigorous and interesting activity. He was the initiator and organizer of all the conferences on scientific photography held before the Great Patriotic War, and from 1948 he was deputy chairman of the Commission on Scientific Photography under the Chemical Division of the Academy of Sciences of the USSR and chairman of its Leningrad branch. He was repeatedly elected chairman of the Council and of the Physical Division of the Russian Physico-Chemical Society, carried out a number of other public duties and assignments. T. P. always treated scientific and public work very seriously and actively, attached great importance to it, knew how to bring much initiative to it, to interest and attract people, and to unite them around common scientific and technical interests.

Lively, sociable, always benevolently disposed toward people, T. P. Kravets deservedly enjoyed the affection and authority of all who had occasion to come into contact with him under the most varied conditions and circumstances. To the last days of his life he preserved exceptional vigor of spirit, an excellent memory, lively and vivid speech, and outstanding capacity for work. He departed life as a fully active and energetic participant in it.