300 MEMOIR ON METEORITES. 



without any knowledge of its having been before proposed. 

 It was sustained by Laplace with all his mathematical skill 

 from the time of its adoption to his death. It was also advo- 

 cated on chemical grounds by Berzelius, whom I have no reason 

 to believe ever changed his views in this matter; and to these 

 we have to add the following distinguished mathematicians 

 and philosophers : Biot, Brandes, Poisson, Quetelet, Arago, 

 and Benzenberg, who have at one time or another advocated 

 the lunar origin of meteorites. 



Some of the above astronomers abandoned the theory, among 

 them Olbers and Arago; but they did not do so from any 

 supposed defect in it, but from adopting the assumption that 

 shooting-stars and meteorites were the same; and on studying 

 the former, and applying the phenomena attendant upon them 

 to meteorites, the supposed lunar origin was no longer possible. 



On referring to the able researches of Sears C. Walker on 

 the periodical meteors of August and November (Trans. Am. 

 Phil. Soc, Jan., 1841), that astronomer makes the following 

 remarks about Olbers's change of views: "In 1836 Olbers, the 

 original proposer of the theory of 1795, being firmly convinced 

 of the correctness of Brandes's estimate of the relative velocity 

 of meteors, renounces his selenic theory, and adopts the cosmical 

 theory as the only one which is adequate to explain the estab- 

 lished facts before the public." 



For reasons already stated it appears wrong to assume the 

 identity of meteorites and shooting -stars; so that whatever 

 difficulty the phenomena of shooting-stars may have interposed 

 in conceiving this or that to have been the origin of meteoric 

 stones, it now no longer exists; and we are fully authorized 

 in forming our conclusions concerning them to the utter dis- 

 regard of the phenomena of shooting-stars. Had Olbers viewed 

 the matter in this light he would doubtless have retained his 

 original convictions, to which no material objection appears to 

 have occurred to him for forty years. 



It is not my object to enter upon all the points of plausibility 

 of this assumed origin, or to meet all the objections which have 

 been urged to it, for most of them have already been ably treated 

 of. The object now is simply to urge such points developed in 

 this memoir as appear to give strength to the lunar theory. 

 They may be summed up under the following heads: 



