NOTES. OXXX111 



avec le soleil, dans le plan meme de 1'ecliptique, a une distance egale 4 la 

 centieme partie de la distance de la terre au soleil, et de donner a la lune et 

 a la terre des vitesses paralleles et proportionnelles a leurs distances a cet 

 astre. Alors la lune, saus cesse en opposition au soleil, eut decrit autour de 

 lui une ellipse semblable a celle de la terre ; ces deux astres se seraient 

 succede 1'un a 1'autre sur Phorizoii ; et comme a cette distance la lune u'eut 

 point etc eclipsee, sa lumiere aurait certainement remplace celle du soleil." 

 Liouville finds, in opposition to this " que si la lune avait occupe a 1'origine 

 la position particuliere que 1'illustre auteur de la Meccmique celeste lui assigne, 

 elle n'aurait pu s'y maintenir que pendant un terns tres court." 



( 595 ) p. 368. On the transporting power of Tides, see Sir Henry De la 

 Beche, Geological Manual, 1833, p. 111. 



( 596 ) p. 368. Arago, " Sur la question de savoir, si la luneexerce surnotre 

 atmosphere une influence appreciable," in the Annuaire pour 1833, p. 157 

 206. The principal authorities are : Scheibler (Untersuch. iiber Einfluss 

 des Mondes auf die Veranderungen in unserer Atmosphare, 1830, S. 20) ; 

 Flaugergaes (twenty years' observations at Viviers) ; Bibl. universelle, Sciences 

 et Arts, T. xl. 1829, p. 265283 ; and in Kastner's Archiv f. die ges. Na- 

 turlehre, Bd. xvii. 1829, S. 3250 ; and Eisenlohr, in Pogg. Ann. der Physik. 

 Bd. xxxv. 1835, S. 141160, and 309329. Sir John Herschel considers 

 it very probable that a very high temperature (much above the boiling point 

 of water) prevails on the surface of the Moon, which is exposed for 14 days 

 together to the uninterrupted and unmitigated influence of the Sun. The 

 Moon must hence, when in opposition, or a few days afterwards, be in some 

 small degree a source of heat to the Earth : this heat, proceeding from a body 

 much below the temperature of ignition, cannot, however, reach the surface 

 of the Earth itself, but is absorbed in the upper strata of our atmosphere, 

 where it changes visible cloud into transparent vapour. The phsenomenon of 

 the rapid dispersion of clouds by the full Moon, when the cloudy canopy is 

 not too dense, is regarded by Sir John Herschel as a " meteorological fact," 

 which (he adds) " is further confirmed by Huraboldt's own experience, aud 

 by the very general belief of Spanish mariners in the American tropical seas." 

 See Report of the Fifteenth Meeting of the British Association for the Advance- 

 ment of Science, 1846, Notices, p. 5 ; and Outlines of Astronomy, p. 261. 



( 597 ) p. 369. Beer und Madler, Beitrage zur phys. Kenntnissdes Sonnen- 

 systems, 1841, S. 113, aus Beobachtungen von 1830 und 1832; Madler, 

 Astronomie, 1849, S. 206. The first, and considerable, correction of the 

 time of rotation found by Dominique Cassini (24 hours, - .0 minutes), was the 



