342 On the Origin of Meteoric Stones. 



pears, that any hypothesis which ascribes an atmospherical origin 

 to meteoric stones, necessarily implies, that the horizontal velo- 

 city is either communicated to them by something of which we 

 cannot at present form even a conception ; or else, that there ex- 

 ists in the atmosphere a projectile power of enormous, nay of 

 almost inconceivable force ; so great, indeed, that the power re- 

 quired in the lunar livpothesis is a mere trifle to it : and yet Mr. 

 Murray describes the latter as being " of the most extraordinary 

 description," and one " not merely of enormous, but of almost 

 inconceivable impetus ;" while beseems to think " that the opi- 

 nion which confines them to our atmosphere," although it really 

 requires a projectile power at least fifty times as great, is attended 

 with so little difficulty that he believes it has " ceased to be pro- 

 llematicaW' and seems quite astonished that Mr. Brande should 

 be of opinion that the lunar hypothesis " is, when impartially con- 

 sidered," — what? not at all problematical? no; merely this, that 

 it is — " neither absurd nor impossible." 



This letter has already extended to a much greater length than 

 I intended ; yet I cannot close it without observing, that the rea- 

 soning which Mr. M. has employed in opposition to the lunar 

 hypothesis, is almost as strange as that which he has used in 

 support of the atmospherical theory; but at present I have not 

 time for a full examination of it: the essence of it may however 

 be given in a few words; and the bare exhibition of it as it really 

 is, when stripped of its gaudy trappings, will probably be suffi- 

 cient to show its absurdity. 



He thinks it unphilosophical merely to suppose a thing to be, 

 which most philosophers believe really to exist; viz. lunar vol- 

 canos. 



Because terrestrial volcanos have not power sufficient to pro- 

 ject a body with the enormous velocity of more than 100,000 feet 

 per second, he thinks it unreasonable to suppose that lunar vol- 

 canos may be able to propel a body with a velocity of about 7000 

 feet per second, although this is little if any thing njore than what a 

 sufficient quantity of our gunpowder would produce at the moon. 

 And lastly, because he chooses to ascribe consequences to the 

 lunar hypothesis, which do not belong to it, we must therefore 

 abandon it. I am, sir, 



Your most obedient servant, 

 Newcastle-upon-Tyne, Oct. 16, 1819. H. Atkinsgn. 



LVIII. Re- 



