A Popular History of Astronomy During the Nineteenth Century / Fourth Edition

by Agnes M. Clerke

FOOTNOTES:

[241] Allgemeine Geographische Ephemeriden, vol. iv., p. 287.

[242] Astr. Jahrbuch, 1823, p. 217. The period (1,208 days) of this body is considerably shorter than that of any other known comet.

[243] "Sicut bombyces filo fundendo, sic cometas cauda exspiranda consumi et denique mori."—De Cometis, Op., vol. vii., p. 110.

[244] Considerable uncertainty, however, still prevails on the point. The inverse relation assumed by Lagrange to exist between distance from the sun and density brought out the Mercurian mass 1/2025810 that of the sun (Laplace, Exposition du Syst. du Monde, t. ii., p. 50, ed. 1824). Von Asten deduced from the movements of Encke's comet, 1818-48, a value of 1/7636440; while Backlund from its seven returns, 1871-1891, derived 1/9647000 (Comptes Rendus, Oct. 1, 1894).

[245] Arago, Annuaire (1832), p. 218.

[246] Hind, The Comets, p. 20.

[247] Phil. Trans., vol. xlvi., p. 204.

[248] Astr. Nach., No. 2,134.

[249] Comptes Rendus, t. cvii., p. 588.