Königsberg: Gebrüder Bornträger, 1841-42. First edition of this collection of 14 treatises, which include descriptions of many of Bessel’s instruments, including the heliometer, with which he was the first to determine accurately the distance of a fixed star. “Modern astronomy of precision is essentially Bessel’s creation” (NNDB).
“Bessel's measurements of positions for about 50,000 stars and rigorous methods of observation (and correction of observations) took astronomy to a new level of precision. He was the first to accurately measure the parallax, and hence the distance, of star other than the Sun. The achievements of Bessel were possible only because he first established the real framework of the universe by making accurate measurements of the positions and motions of the nearest stars, making corrections for various measuring errors caused by imperfections in his telescopes and by disturbances in the atmosphere.” (Erik Geregersen, The Universe, p.55). ”Modern astronomy of precision is essentially Bessel’s creation. Apart from the large scope of his activity, he introduced such important novelties as the effective use of the heliometer, the correction for personal equation (in 1823), and the systematic investigation of instrumental errors. ... Especial attention should be directed to his Astronomische Untersuchungen (2 vols. 1841-42)” (Brittanica).
The Astronomische Untersuchungen consists of fourteen separate works by Bessel; some are re-worked editions of earlier works published in the Astronomische Nachrichten, and others appear here for the first time.
2 vols. 4to: 264 x 214 mm. Pp. vi,(2:contents),313,(1:errata); iv,(2:contents),307,(1:errata). Bound in two, uniform contemporary boards with leather spine label. Faint rubber stamps of the Glasgow Observatory to titles. A fine set, scarce.