BROWN, ERNEST WILLIAM. An Introductory Treatise on the Lunar Theory. xvi, 292 pages, with errata slip tipped in. the astronomer wallace john eckert's copy, with his signature (see lot 57) * BROWN, ERNEST WILLIAM; and HEDRICK, HENRY BENJAMIN. Tables of the Motion of the Moon. xii, , 140; 39, ; , 223, ; , 99, ; , 56; 102 pages. 6 parts in one volume. Together, 2 volumes. 8vo, 260x168 mm, original cloth, needs rebacking, cover corners worn through; and folio, 321x242 mm, later linen, spine and top of front cover faded; contents of both volumes clean. Cambridge: University Press, 1896; New Haven: Yale University Press, 1919
first editions. Bound in the second work is Brown and Hedrick's Complement to the Tables of the Motion of the Moon, containing the Remainder Terms for the Century 1800-1900, and Errata in the Tables. Offprint from Transactions of the Astronomical Observatory of Yale University, Volume 3, Part 5, pages , 157-204. [New Haven, 1926.] Brown's achievement in celestial mechanics lay in developing the work of George William Hill into a practical method for computing lunar positions. 'Brown completed his theory in 1908, and the tables derived from it in 1919. These served as the basis for British and American lunar ephemerides until 1959. The Hill-Brown theory represents an order of magnitude increase in accuracy over that of Delaunay and the pinnacle of success for quantitative perturbation techniques'—Linton, From Eudoxus to Einstein, page 412. BEA, page 125. DSB II, 516.