1786. 8vo, pp. [iv], 162, [2]; with two folding engraved plates; fore-edge of one plate a little furled, lightly browned throughout with some marginal dust-soiling and occasional spotting; a crisp copy; ex-libris stamp from the the British Astronomical Association Victoria Branch, Melbourne, on front free endpaper; in contemporary tree calf, red morocco label lettered in gilt on spine, head and tail of spine worn exposing cords, joints neatly repaired, extremities lightly bumped and rubbed; a good copy. First edition of this series of letters on practical astronomy, by the Toulouse astronomer Augustin Darquier de Pellepoix (1718-1802), notable as the discoverer of the Ring Nebula M57, and as one of the first people properly to observe Uranus. The work includes a detailed explanation of his research and observations, giving technical information on the instruments used, on his methodology, and includes a number of astronomical tables.
Of particular interest, this is followed by a reprint of his 1771 work aimed at a female audience introducing the constellations Uranographie ou Contemplation du Ciel. It describes the fifteen brightest stars and constellations, each of which is illustrated in the two folding engraved plates. According to Lalande, the work was written for Mme d'Etigny as a guide to understanding the skies, and at the end of the dedication Pellepoix expresses his hope that it will ‘exciter la curiosité, et engager ses lecteurs à pénétrer une science, qui, suivant une de ses expressions ordinaires, est un jouissance perpétuelle’ (p. 136).
To conduct his research, Darquier de Pellepoix had an observatory built at his home in Toulouse, and hired scholars to train pupils and help with calculations. In addition to the present work, he published a number of papers on astronomy and translated Simpson's Geometry and Lambert's Cosmological letters. His catalogue of star positions, compiled between 1791 and 1798, was used by Lalande for his catalogue of 1801.