310 MEMOIR ON METEORITES. 



medium at a great velocity would not show this. In fact, if 

 almost any of the specimens of meteorites in our cabinets were 

 discharged from a cannon, even in their limited flight the scal- 

 loping motion would be seen. 



This then will conclude with what I have to say in contradic- 

 tion to the supposition of large solid cosmical bodies passing 

 through the atmosphere and dropping small portions of their 

 mass. The contradiction is seen to be based, first, upon the fact 

 that no meteorite is known of any great size — none larger than 

 the granite balls to be found at the Dardanelles alongside of the 

 pieces of ordnance from which they are discharged ; secondly, 

 on the fallacy of estimating the actual size of these bodies from 

 their apparent size; and lastly, from its being opposed to all 

 the laws of chance that these bodies should have been passing 

 through an atmosphere for ages and none have yet encountered 

 the body of the earth. 



To sum up the theory of the lunar origin of meteorites, it 

 may be stated that the moon is the only large body in space of which 

 we have any knowledge possessing the requisite conditions demanded 

 by the physical and chemical properties of meteorites; and that they 

 have been thrown off from that body by volcanic action (doubtless 

 long since extinct), and, encountering no gaseous medium of resist- 

 ance, reached such a distance as that the moon exercised no longer 

 a preponderating attraction; the detached fragment, possessing an 

 orbited motion and an orbital velocity, which it had in common with 

 all parts of the moon, but now more or less modified by the projectile 

 force and new condition of attraction in which it was placed with 

 reference to the earth, acquired an independent orbit more or less 

 elliptical. This orbit, necessarily subject to great disturbing influ- 

 ences, may sooner or later cross our atmosphere and be intercepted 

 by the body of the globe. 



In concluding this lengthy examination I must say that a 

 discussion of the phenomena accompanying the falling of me- 

 teorites has been avoided, as well as many points connected 

 with their history. This has been done from its having no 

 immediate connection with the object of this memoir, which is 

 intended simply to present some new views and many old views 

 in a new light, so as to awaken attention to the study of this 

 most interesting class of bodies. 



