Walther Bothe

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Walther Bothe (1954)

Walther Wilhelm Georg Bothe (born January 8, 1891 in Oranienburg , † February 8, 1957 in Heidelberg ) was a German physicist . His work was an important contribution to the foundation of modern nuclear physics . For the development of coincidence measurement and the discoveries made with it, he received the Nobel Prize in Physics in 1954 .


Childhood and adolescence 1891–1920

Bothe was born in the house on Berliner Straße 2 in Oranienburg as the son of the master watchmaker Friedrich Bothe and the tailor Charlotte, née Hartung. He spent his childhood and much of his youth in his hometown. From 1892 he lived at Bernauer Strasse 7. Both houses were completely destroyed by bombs in the Second World War . Bothe was distinguished by a sharp mind and relentlessly logical thinking, had a talent for music and painting and a determined will.

Easter 1908 he passed the Abitur at the Oberrealschule in Berlin and studied physics, mathematics, chemistry and musicology at the University of Berlin between 1908 and 1913. His studies were largely financed by himself through private tuition, casual work and scholarships.

After passing the teaching examination in 1913, Bothe worked briefly as an assistant at the Agricultural University in Berlin, but soon became a scientific assistant at the Physikalisch-Technische Reichsanstalt (PTR) in the radioactive laboratory founded by Hans Geiger the year before . As a student of Max Planck he received his doctorate in 1914 for Dr. phil. with the theoretical work "On the molecular theory of refraction, reflection, dispersion and extinction ". During the First World War , Bothe was taken prisoner by Russia in 1915 , from which he did not return until 1920. In captivity in Siberia, he learned Russian and deepened his mathematical knowledge. During this time of captivity he built a match and a soda factory with the most primitive means. He also continued to pursue math problems and devoted his energies to studying the Russian language.

On July 8, 1920, Bothe married Barbara (Varvara) Belova in Moscow. He had met her in Berlin before the war and was in constant correspondence with her. The marriage resulted in two daughters.

Years of work after the First World War 1920–1932

After Bote's return from captivity, he worked under the direction of Hans Geiger at the Physikalisch-Technische Reichsanstalt until 1925 and succeeded Geiger as head of the laboratory in 1925. He held this post until 1930. From Hans Geiger, he learned to deal experimentally with the phenomenon of radioactivity and thus developed into a nuclear physicist who was particularly well trained theoretically and experimentally. In 1924 he and Hans Geiger began with experiments to investigate the Compton effect (Bothe saw the recoil electrons from collisions with X-rays a few months before the discovery of the Compton effect in Wilson chambers) and they developed the coincidence method .

The work “The Quantum Theory of Radiation”, written by Niels Bohr together with Hendrik Anthony Kramers and John Clarke Slater in 1924, in which it was assumed that the theorems of momentum and Conservation of energy at the atomic level would only have statistical validity. The experiments by Hans Geiger and Walter Bothe as well as Arthur Holly Compton and Alfred W. Simon, who proved that the conservation laws also dominate the individual elementary process , very soon showed that this assumption could not be maintained . With this, the Copenhagen justification of the "dispersion-theoretical method" used, the radiation theory of Bohr, Kramers and John Slater and the only statistical conservation of energy and momentum in atomic processes required therein collapsed. The refutation of the theory of Bohr, Kramers and Slater, in which Geiger and Bothe applied the coincidence method, attracted both great attention at the time.

In 1925, Bothe completed his habilitation with Max Planck at the University of Berlin “On the elementary process of photoelectric electron release” and was the last of Planck's seven habilitation students. The following incident is reported from his time in Berlin: When Otto Frisch , Lise Meitner's nephew , walked down the corridor near Walther Bothe's laboratory, he liked to whistle his interpretation of Bach's Brandenburg Concerts. As a result, Bothe was regularly distracted when counting alpha particles , which cost him a lot of time to repeat the experiments.

Bothe is characterized by Arnold Sommerfeld in a letter to Tübingen on June 11, 1929:

"Bothe, Physikal.-Techn. Reichsanstalt, Charlottenburg, is a highly original mind and an excellent experimenter. Together with Geiger he did famous precision work, but even after Geiger's departure he did his own research with great success. I am not informed about his teaching qualification, which he has probably not yet had the opportunity to test. "

- Arnold Sommerfeld

In 1929 Bothe became a private lecturer and associate professor at the University of Giessen , in 1930 a full professor at the same university and director of the Physics Institute. He was the first to include quantum mechanics in his lectures. The Giessen University was founded in 1607 by Landgrave Ludwig, making it one of the oldest German universities. A number of great physicists held a chair in Giessen. In addition to Walther Bothe, they also included Wilhelm Conrad Röntgen , Wilhelm Wien , Christian Gerthsen and Wilhelm Hanle. In 1930 Walter Bothe succeeded in discovering the excited atomic nucleus in Giessen . The situation of experimental physics in Gießen was completely changed by Bothe despite his only two years of activity. Giessen had become a topical research facility.

Work in the Nazi era 1932–1945

Walther Bothe, Stuttgart 1935

The Heidelberg Kaiser Wilhelm Institute (KWI) for medical research was inaugurated in May 1930 under the direction of internist Ludolf von Krehl . Krehl strove to collaborate with other scientific disciplines for his circulatory research, and so in this institute four disciplines were combined in independent sub-institutes with equal rights: pathology, physiology, physics and chemistry. The historical circumstances meant that the focus of work at the Heidelberg KWI shifted towards chemistry and physics towards the end of the thirties, which were represented by Richard Kuhn and Walther Bothe.

In 1932 Bothe went to Heidelberg University and succeeded Philipp Lenard . As a result of the 1933 incoming political changes after the seizure of power by the National Socialists , however, he joined the Ordinariate back and by the Institute. In 1934 he was appointed head of the Institute for Physics at the Kaiser Wilhelm Institute for Medical Research - later part of the Max Planck Institute for Nuclear Physics - and was an honorary professor until 1957, at the same time from 1934 to 1945 .

Bothes interests were not so much biological. That is why in 1943, at the suggestion of Bothe , Gerhard Schubert, who was already medically supervising the staff working at the Paris cyclotron , was called in for biological experiments, in particular animal experiments with artificial radioactive substances.

Bothe used a harsh tone that often came close to that of a conscript sergeant when dealing with doctoral students and younger assistants. Sometimes he was also not very committed to colleagues. This probably had its origin in the military tone that was common in parts of the imperial Physikalisch-Technische Reichsanstalt in his youth. On the other hand, it arose from the attitude of the Planck school. Lise Meitner stated that “he never did or did not do anything because it could have been useful or harmful to him. What he saw to be right, he did without regard to his own person. ” This motto was not necessarily conducive to the work in the institute and the position of the institute under the political circumstances of the thirties and forties. His colleague Wolfgang Gentner had a balancing effect here. He was fully respected by Bothe and was able to bring out the generous, cosmopolitan atmosphere of the Frankfurt and Paris laboratories, which he had got to know in his youth, for the benefit of the institute and especially the younger employees.

After 1942, Bothe gradually returned to his original basic research . He also worked on the controlled nuclear fission chain reaction. During this time the construction of the first German cyclotron, a particle accelerator that Bothe constructed together with his assistant Wolfgang Gentner, took place. With this, the almost ten-year collaboration between Gentner and Walther Bothe came to an end, which has proven to be so fruitful because Gentner happily complemented Bothe with his eye for the essentials, with his generosity and his workforce based on solid health.

Work after the war 1945–1957

In 1953, at the age of 61, Bothe retired to the post of director of the Institute for Physics at the Max Planck Institute for Medical Research on Jahnstrasse in Heidelberg with the intention of only working with a few highly qualified assistants and students. Three important scientific projects fall during this time: the reconstruction of the cyclotron, the further development of nuclear spectroscopy and the continuation of the investigation of cosmic rays . In the 1950s and 1960s, the work of Bothe and his colleagues found increasing international recognition.

Along with other Nobel Prize winners, Bothe was one of the signatories of an appeal of July 15, 1955 to statesmen of the world to renounce violence as a means of politics.

The role of his former colleagues Wolfgang Gentner and Heinz Maier-Leibnitz in German and European science projects was recognized. B. the establishment of the European Center for Nuclear Research ( CERN ) and the Institut Laue-Langevin (ILL).

With increasing age, Bothe's illnesses increased. Progressive vasoconstriction had made it necessary to amputate a leg. He was unable to recover properly from this operation. One year after his death in 1958, the Institute for Physics was given an independent status as the Max Planck Institute for Nuclear Physics under the direction of Wolfgang Gentner.

As a pioneer of modern nuclear and elementary particle physics, Walther Bothe left a lasting mark on the history of physics in the 20th century with a wealth of outstanding scientific achievements.

Scientific work

As described above, one of his most important achievements is the development of the coincidence method.

Coincidence Method and Cosmic Rays

After Victor Franz Hess who in 1912 ballooning cosmic radiation had discovered it was his contemporary Walter Bothe together with Werner Kolhörster , 1929 in coincidence measurements prove penetrating extraterrestrial radiation of cosmic radiation services. They also proved that it was particle radiation and not gamma radiation, as was often assumed at the time (especially according to a theory by Robert Millikan ).

In 1929, Bothe and Kolhörster developed a special method to display the discharge of two or more separate Geiger-Müller counter tubes only if the measurement was made within a predetermined time interval . This new “coincidence counting” made it possible to follow the path of a charged particle through the counter tubes.

Discovery of artificial nuclear excitations

In 1928 and in the following years he and Hans Fränz investigated the bombardment of boron and then also other atomic nuclei with alpha particles, with groups of protons formed as scattering products that had defined energy differences. This was a clear indication of nuclear excitations and to confirm his conjecture, Bothe looked for gamma radiation with the same energy that he found in 1930 (with boron with an energy of 3 MeV). For this, too, he developed a coincidence method.

Discovery of the neutron

Walther Bothe and his student Herbert Becker were the first to deal with the discovery of the neutron . In 1930 they described an unusual type of “gamma radiation” that arose when they bombarded beryllium with polonium alpha particles with the aim of confirming Ernest Rutherford's theory and finding out whether very energetic rays are emitted during this process. However, he did not recognize that it was a new particle. James Chadwick later received the Nobel Prize for the discovery of the neutron .

Bothe dealt with the fundamental properties and structure of the atom. He had little interest in medical research - the offer in Heidelberg was obviously an attempt to prevent one of Germany's leading experimental physicists from leaving the country. In the 1930s, he and his colleagues were among the first scientists to observe the “nuclear photo effect”, carry out nuclear spectroscopic investigations and produce artificial isotopes . The nuclear photo effect is a reaction of a photon with an atomic nucleus.

Cooperation with Wolfgang Gentner, Artificial Nuclear Gamma Radiation

At the end of 1935, after Wolfgang Gentner's Paris scholarship expired , his work topics led him to Walter Bothe in Heidelberg. Bothe, together with Horn, came to similar results as Gentner during his investigations into the passage of hard gamma radiation through matter and also examined neutrons from nuclear reactions. Gentner continued his Parisian work in Heidelberg with Bothe on the one hand and Rudolf Fleischmann on the other . When trying to determine the energy dependency of the nuclear photo effect on beryllium and considering the continuation of this work, it became clear that the energy of gamma radiation is too small relative to the binding energy of the neutrons in the nucleus and that gamma radiation sources with significantly higher energy and with significantly greater intensity are needed. Bothe and Gentner then decided to build a band generator based on Van de Graaff . This device, equipped with the essential features and instruments of modern electrostatic accelerators, was set up incredibly quickly by Gentner. As early as November 1936, the excitation function for

Up to 500 keV energy was measured and in the summer of 1937 extensive data were available on the nuclear photo effect of the 17 MeV 7 Li (p, gamma) radiation on many medium-weight and heavy nuclei. The cross section , a measure of the probability that a reaction will take place as a result of an interaction between an incident particle and another particle, was two powers of ten greater than that calculated by Hans Bethe and Placzek. In 1937, Wolfgang Gentner succeeded in generating artificial radioactivity. To do this, they used a high voltage system with one million volts. Gentner and Bothe thus discovered the possibility of producing a large number of artificially radioactive nuclides . This discovery of the nuclear photo effect on medium-heavy and heavy nuclei was the most important success of the Bothe'schen Institute in these years. In a way, this success gave Gentner a special position.

The cyclotron

After the armistice between Germany and France in the summer of 1940, Bothe and Gentner were commissioned to inspect the Paris cyclotron , which Joliot had started to build. In 1940 Walter Bothe and Wolfgang Gentner appeared at the Paris Institute with staff from the Army Weapons Office. Joliot was absent and they found that the cyclotron was not yet running due to defects in the high frequency system. Bothe was commissioned to build a cyclotron in Heidelberg, and in the course of 1941 he had already managed to arrange almost everything that was necessary for this. The magnet finally arrived in March 1943, and the cyclotron was already in use in the autumn of the same year. Bothe told Albert Speer that the machine would only be useful for medical and biological research.

Work in the uranium project

Walter Bothe was one of the leading German experimental physicists in the 20s to 50s. Bothe's motives for joining the uranium project were complex. He was opposed to the National Socialist regime, especially after his removal from the university in 1933. But although he also knew that the Gestapo had been monitoring him for years, he volunteered for war research for patriotic reasons. After the war he found neither apologetic nor explanatory words for this, as other members of the Uranium Association did. Politically patriotic to nationalistic, he began in Heidelberg in June 1940 for the Heereswaffenamt (HWA) to carry out measurements on the neutron cross-section of carbon. In January 1941 he measured a completely wrong value for the diffusion length of neutrons in graphite, because he used contaminated graphite, which he wrongly believed to be pure. So it came to the momentous exclusion of graphite as moderator in the German uranium project, in contrast to the USA, where Enrico Fermi operated the first reactor in Chicago with graphite as moderator. A different opinion from Georg Joos in Göttingen, who recognized the necessity of high-purity graphite, did not prevail and Paul Harteck in Hamburg was discouraged from further experiments. The error was not recognized until 1945 during tests in Haigerloch, where graphite was used as a reflector.

The Alsos Mission

As part of the Alsos mission , American special representatives reached Heidelberg in mid-1945, as the only German cyclotron was located there, in what was then the Kaiser Wilhelm Institute for Medical Research. The takeover of the institute took place without incident. Bothe, who headed the institute, was interrogated and his work was confiscated. However, he informed Goudsmit that he had burned all of his classified reports as directed by the government. Bothe refused to testify until the German surrender, but he was not interned in England like the other members of the uranium association. Finally, Bothe handed over all the remaining documents to Alsos, but did not want to comment on secret research at his institute.

After the war

During the occupation, Bothe and Siegfried Flügge produced a volume on nuclear physics and cosmic rays that dealt with the work of the uranium project as part of the “Field Information Allied Technical (FIAT) reports” .

In the second half of the 1940s, finding food and a roof over your head was the main concern, which is why Bothe struggled to keep his work group going and do something like serious research. Although he was not allowed to work in his original field of nuclear physics, Bothe was reinstated as director of the Institute for Physics at Heidelberg University. He used this position to keep his old working group and to modernize the institute and put it on a solid footing.

Walther Bothe returned to the 1st Physics Institute at the university in 1945. In 1946, however, Wolfgang Gentner decided to go to Freiburg, where the Physics Institute had been completely destroyed.

Even during the war, Bothe and Gentner had worked out plans for a new Kaiser Wilhelm Institute with larger particle accelerators. Gentner took up these ideas again. In close contact with the nuclear physicists at the university, in particular Otto Haxel and J. Hans D. Jensen , Gentner tackled the installation of a tandem accelerator with a maximum voltage of 6 MV as a first step. In addition, a special building for cosmophysics was planned in order to determine the age of meteorites using radioactive methods . Young physicists from Freiburg came to Heidelberg with Gentner for both fields of work.

From May 1946 until his death, Bothe headed the Physics Institute at the Max Planck Institute (the successor to the Kaiser Wilhelm Institute) at Heidelberg University.

In 1947, Walther Bothe, who after the Second World War was the sole professor of physics in Heidelberg and also headed the nuclear physics department of the Kaiser Wilhelm Institute for medical research there, tried to win Hans Jensen over to Heidelberg. Jensen followed this call in the winter semester of 1948/49. Apart from a substitute course given by Walter Wessel , who soon went to the United States, there had been no lectures on theoretical physics in Heidelberg after the end of the war. The first theoretical-physical seminar was held by Jensen's assistant, Helmut Steinwedel , who had come to Heidelberg a few months before Jensen. Then there was Michael Danos , whom Jensen also knew from Hanover, and a little later Heinz Koppe and Arnold Schoch . The establishment of the Institute for Theoretical Physics had started.

Bothe put the only existing cyclotron in Heidelberg back into operation before 1948. He carried out nuclear physics experiments with his students and produced radioactive preparations for the neighboring clinic. To convert the cyclotron, Bothe brought Christoph Schmelzer from Jena, who completed his habilitation in 1949 with a thesis on the dielectric behavior of matter with a polar structure. Bothe also arranged that Hans Jensen from Hamburg was appointed to Heidelberg in 1949, as was Otto Haxel from Göttingen.

Interest in the Heidelberg research arose. Wolfgang Pauli , who initially stayed away from Germany after the war, was persuaded by Jensen to come to Heidelberg. The opportunity to do so was on Walther Bothe's 60th birthday. Even Hans Bethe , George Gamow , Maria Goeppert-Mayer , Lothar Nordheim , Isidor Isaac Rabi , Victor Weisskopf , Eugene Wigner and many other outstanding personalities soon came to visit to Heidelberg.

After the war, physical societies were initially set up as separate associations for the British Zone, for Württemberg, Baden, Palatinate, for Hesse, and for Bavaria and Berlin. In the south-west, 160 members gathered under the chairmanship of Bothe.

On February 29, 1952, a commission for atomic physics of the German Research Foundation (DFG) was formed, to which Walther Bothe should also belong under Heisenberg's chairmanship.

In the following years, Bothe devoted himself to research in the field of nuclear physics and the application of artificially generated radioactive elements. However, progressive illness forced him to withdraw gradually from the research life.

After Bothe's death in February 1957, the future of his Heidelberg Institute was discussed for a long time. Voices that had previously pleaded for closure finally faded into the background because the physicists at Heidelberg University brought the institute's scientific capabilities to bear. The converted cyclotron had been in operation since 1956, and work on the failure to maintain parity in the weak interaction was carried out worldwide, which is recognized throughout the world.


He painted (oil and watercolor), had a penchant for impressionists in painting, and played the piano very well (with a penchant for Bach before Beethoven).


In 1952 Bothe was accepted into the order Pour le mérite for science and the arts and was the only physicist next to Max von Laue .

In 1953, Bothe was awarded the Max Planck Medal . The Max Planck Medal is an award that has been presented annually by the German Physical Society (DPG) since 1929 for special achievements in the field of theoretical physics. This award is considered to be the most important in this subject in Germany. It consists of a certificate and a gold medal with a portrait of Max Planck.

Walther Bothe received the Nobel Prize for Physics on December 10, 1954 together with the German researcher Max Born who emigrated to England in 1929. The coincidence method developed by Bothe and the discoveries made with it were honored. The method from elementary particle and nuclear physics draws conclusions from the simultaneous or with a defined time interval occurring of nuclear physical measurements on different characteristics of elementary particles. By using various detection devices, flight paths, speeds and ranges of individual particles can be determined. The findings are of fundamental importance for understanding the structure of matter and different radiations. Bothe was unable to travel to Stockholm for health reasons. At his request, his daughter Dr. Elena Riedel received the award. The German version of his Nobel Lecture is in the archive of the Max Planck Society (MPG). See Peter Brix, “Hans Geiger, Ein Wegbereiter der moderne Naturwissenschaft”, Heidelberger Jahrbücher XXVII 1983, p. 110.

In 1955 Bothe received the Great Cross of Merit of the Federal Republic of Germany, in 1956 an honorary doctorate from the University of Giessen.

In Oranienburg, Ernst-Thälmann-Strasse was renamed Walther-Bothe-Strasse in 1993.

Bothe was a member of the Prussian , Saxon , Göttingen (since 1933) and Heidelberg Academy of Sciences .

The asteroid (19178) Walterbothe was named in his honor.


Bothe wrote more than 200 scientific publications in the fields of optics to cosmic ultra-radiation, u. a .:

  • On the molecular theory of refraction, reflection, dispersion and extinction, Annalen der Physik, 4th part, Volume 64, 1921, pp. 693-712 (dissertation)
  • with Friedrich Adolf Paneth: Radio elements as indicators , in Tiede, Richter Handbook of Working Methods in Inorganic Chemistry , Volume 2, 2nd half, De Gruyter 1925
  • with Hans Geiger: A way to experimentally check the theory of Bohr, Kramers, and Slater, in Zeitschrift für Physik, Volume 26, 1924, p. 44
  • with Hans Geiger: About the essence of the Compton effect; an experimental contribution to the theory of radiation, Zeitschrift für Physik, Volume 32, 1925, pp. 639-663
  • Light quanta and interference, 1927
  • with Werner Kolhörster: The essence of cosmic radiation, Zeitschrift für Physik, Volume 56, 1929, pp. 75-77
  • with H. Becker: Artificial excitation of nuclear γ-rays, Zeitschrift für Physik, Volume 66, 1930, pp. 289-306
  • Radioactivity: the radioactive decay, in Geiger, Scheel, Handbuch der Physik , Volume 22, 1926
  • Absorption and scattering of X-rays, in Geiger, Scheel, Handbuch der Physik, Volume 23, 1926
  • The passage of electrons through matter, in Geiger, Scheel, Handbuch der Physik, Volume 24, 1927
  • Walter Bothe: To simplify coincidence counts , Zeitschrift für Physik, Volume 59, 1929
  • with Wolfgang Gentner, Heinz Maier-Leibnitz : Atlas of typical cloud chamber images, with an introduction to Wilson's method . J. Springer, Berlin 1940.
  • Walther Bothe: The physicist and his tools , lectures and writings, Prussian Academy of Sciences, Walter de Gruyter & Co., Berlin 1944.
  • with others revised by Friedrich Kohlrausch : Textbook of practical physics , 16th edition, Teubner 1930
  • The Neutron and the Positron, Die Naturwissenschaften, Volume 21, 1933
  • with Hans Jakob von Baeyer: Coincidence studies on core processes . In: News from the Society of Sciences in Göttingen. Physics, astronomy, geophysics, technology . New episode. Volume 1, 1935, No. 16, 195-197
  • with Rudolf Fleischmann : Slow Neutrons, Results of the Exact Natural Sciences, Volume 16, 1937
  • with R. Fleischmann: Artificial core transformation, results of the exact natural sciences, Volume 14, 1935
  • with Siegfried Flügge (Ed.): Nuclear Physics and Cosmic Rays (= Natural Research and Medicine in Germany 1939-1946, Volume 14), 2 volumes, Weinheim 1947 (FIAT Review of German Science)

See also


The following were also used for the article:

  • Peter Richter: Seven-part series of articles about Walther Bothe in the “Oranienburger Generalanzeiger”, December 2004.
  • Peter Richter: Walther Bothes merits . Märker 4./5. December 2004.
  • Michael Bar – Zohar: The Hunt for German Scientists (1944–1960) . Propylaea Verlag, Berlin. Biography, Manfred von Ardenne , Walther Bothe, Wernher von Braun , Paul Goercke, Otto Hahn , Eugen Sänger , Max von Laue a . a.
  • John Cornwell: Researching for the Leader. German scientists and the Second World War . Gustav Lübbe Verlag, 2004.
  • Rainer Karlsch : Hitler's bomb. The secret history of the German nuclear weapon tests . German Publishing House Munich, 2005.
  • Wolfgang Horlamus: Chronicle of the requirements and history of the nuclear energy industry in the GDR (1939 to 1990) . 1994.
  • Mark Walker : Research Program “History of the Kaiser Wilhelm Society in National Socialism” Otto Hahn - Responsibility and Repression .
  • Max Planck Institute for the History of Science, Horst Kant: On the history of physics at the University of Strasbourg during the Second World War . Preprint 73, 1997.
  • Klaus Schlüpmann: The Past in the Field of View of a Physicist - Hans Kopfermann 1895–1963 . 2002

Web links

Commons : Walther Bothe  - Collection of images, videos and audio files

Individual evidence

  1. ^ Wolfgang Gentner: Obituary for Walther Bothe. In: Journal of Nature Research A . 12, 1957, pp. 175-176 ( online ).
  2. See Manfred Jacobi Photons or Waves: The Debate about the Bohr-Kramers-Slater Theory 75 Years Ago , Physikalische Blätter, Volume 55, 1999, pp. 51–54, doi : 10.1002 / phbl.19990551012
  3. Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 46.