METEORIC STOSTES. 225 



place where the motion is genei'ated. In fact, we have every 

 reason to believe, from optical considerations, that the moon 

 has no atmosphere. 



A body falling from the moon upon the earth, after being 

 impelled by such force as we have been describing, would not 

 reach us in less than two days and a half. It would enter 

 our atmosphere with a velocity of nearly 25,000 feet in a 

 second ; but the resistance of the air increasing with the 

 velocity, would soon greatly reduce it, and render it uniform. 

 We may remark, however, that all the accounts of fallen 

 stones agree in attributing to the luminous bodies a rapid 

 motion in the air, and the effects of a very considerable mo- 

 mentum to the fragments which reach the ground. The 

 oblique direction in which they always fall, must tend greatly 

 to diminish their penetrating power. 



While we are investigating the circumstances that render 

 this account of the matter highly probable, we ought not to 

 omit one consideration, which lies wholly in the opposite 

 scale. The greater part of these singular bodies have first 

 appeared in a high state of ignition ; and it does not seem 

 easy to conceive how their passage through" so rare a fluid as 

 the atmosphere could have generated any great degree of 

 heat, with whatever rapidity they may have moved. Viewing, 

 as we do, the hypothesis of their lunar origin as by far the 

 most probable in every other respect, we will acknowledge 

 that this circumstance prevents us from adopting it with 

 entire satisfaction. And while we see so many invincible 

 objections to all the other theories which have been offered 

 for the solution of the difficulty, we must admit that the 

 supposition least liable to contradiction from the facts, is 

 nevertheless sufficiently exceptionable, on a single ground, to 

 wan-ant us in concluding with the philosophical remark of 

 Vauquelin, " Le parti le plus sage qui nous reste a prendre 

 dans cet etat des choses, c'est d'avouer franchement, que nous 

 ignorons entierement 1'origine de ces pierres, et les causes 

 qui ont pu les produire." 



If, however, a more extensive collection of accurate obser- 



