Königsberg in Preussen, Gebrüder Bornträger, 1841-1842. Two volumes in one (26.5 x 21.9 cm). 4to. viii, 314; iv, 308 pp. Contemporary style marbled boards. Red morocco label with gilt title on the spine.

Important and rare scientific contributions by the German astronomer and mathematician Friedrich Wilhelm Bessel (1784-1846), published not long before his untimely death. Bessel, who was director of the Königsberg Observatory, determined the position of 50,000 stars, producing a catalogue that became the standard for many years. He was the first to use a star's parallax to determine its distance (61 Cygni, at a distance of nearly 10 light years). This may be regarded as the starting point of understanding the depth of space. As a mathematician, Bessel is best known for developing the so-called Bessel functions, which are important for the solution of equations used in both classical physics and quantum physics. Without formal training in science, Bessel became a fellow of the prestigious Royal Society. This work, published in two parts, contains 14 different contributions, some original and not published before (e.g. a paper on the weight of Jupiter), while others have been reworked from Bessel’s earlier studies. He wrote the prefaces to both parts and it is clear that he regarded these contributions as the most important he made, especially from a practical point of view. "From 1840 on, Bessel's health deteriorated ... After two years of great suffering, Bessel died" (DSB). This work, therefore, is in a way Bessel's scientific testament. A very good, complete copy. Rare, with no auction records for the last 35 years. DSB II, p. 98; Houzeau & Lancaster, 3569; Not in Cat. BM(NH).