Carl Friedrich Gauss (1777–1855) was famous in his lifetime as a great mathematician and scientist at the University of Göttingen who hardly ever travelled anywhere but maintained a massive (inter)national scientific correspondence. There are over a dozen volumes of the exchanges with his principal correspondents; this one extends the range somewhat in reproducing his letters with scientists who spent at least part of their careers in a university in Russia. About eighty letters were written by seventeen correspondents and around forty by him; they date right across his career.

Quite often the subject matter was mathematics, but two other topics were prominent. One was astronomy, for Gauss's post at the university was as director of the astronomical observatory, not as professor of mathematics. The other, from the 1830s onwards, was the project that he directed with the physicist Wilhelm Weber to produce a geomagnetic map of the Earth (for which Alexander von Humboldt was the initial inspiring figure). The letters themselves seem usually to be typical in content for their respective concerns; exceptional is the manner of their editing, in the second part of the book. Each correspondent has his own chapter, which starts with a likeness and a timeline, continues with career information and details of the contacts with Gauss, and ends with a transcription of the letter(s). One may feel at times a surfeit of information: for example, the best-known mathematician correspondent is Nikolai Lobachevskii at Kazan′, one of the founders of non-Euclidean geometry, an insight that Gauss had worked out for himself; the sole letter is an expression of thanks for election in 1843 as corresponding member of the Göttingen Academy of Sciences, which is transcribed after forty pages of editorial preparation and has been published before.

Nevertheless, there is much valuable information in these chapters, and the first part of the book is of more general interest, since across 140 pages it provides a wealth of information about both Gauss's interests and Russian academic life. It covers the universities of his correspondents and the Saint Petersburg Academy, the development of a geomagnetic map for Russia, and the surprisingly large number of published translations of Gauss's books and papers into Russian, which was started in the 1830s by students and continued especially in the Soviet period. Even the circumstances of Gauss's learning and reading Russian are covered. The absence of a subject index is regretted, but the book is lavishly provided with a huge bibliography of primary and historical sources, capsule biographies of the large number of figures named in the book, and illustrations of various kinds, including of Gauss's enviable calligraphy. The edition is a valuable contribution to the history of Russian science in the mid- and late nineteenth century, far beyond the matters discussed in the correspondences.