Untersuchungen uber die Lichtstarke der Planeten Venus, Mars, Jupiter und Saturn, verglichen mit Sternen, und uber die relative Weisse ihrer Oberflachen. Nebst einem anhange, enthaltend die Theorie der Lichterscheinung des Saturn.

Munich:: G. Franz, 1859. Offprint from: Monumenta saecularia der Bayerischen Akademie der Wissenschaften, 1859., 1859. 4to. [iv], 102 pp. Tables, 1 plate. Dis-bound. Very good. FIRST EDITION. "Seidel's photometric measurements of fixed stars and planets were the first true measurements of this kind. The precise evaluation of his observations by methods of probability theory, considering atmospheric extinction, are worthy of special mention. At Steinheil's suggestion Seidel derived trigonometric formulas for points lateral to the axis of an optical system; (truncated) they soon became important for astronomical photography and led to the production of improved telescopes." DSB, XII, p. 289. Houzeau & Lancaster, II, col. 1115, 1322, 1354. (Inventory #: S6853)