170 TENTH ANNUAL REPORT OP 



proof is urged, we are justified, I think, in assuming the contrary to be 

 true, for we must not measure the convulsive throes of nature at all 

 periods by what our limited experience has enabled us to witness. 



With the existence of volcanic action in the moon without air 

 or water, I have nothing at present to do, particularly as those who 

 have studied volcanic action concede that neither of these agents is 

 absolutely required to produce it ;. moreover, the surface of the moon 

 is the strongest evidence we have in favor of its occurring under those 

 circumstances. 



The views here advanced do not at all exclude the detachment of 

 these bodies from the moon by any other force than volcanic. It is 

 useless for us to disbelieve the existence of such force merely because 

 we cannot conceive what that force is ; suffice it to know that the meteor- 

 ites are fragments, and if so, must have been detached from the parent 

 mass by some force. A study of the surface of the moon would in- 

 duce the belief that any disruption caused by heat might have oc- 

 curred^ as that arising from the great tension produced by cooling,^ as 

 exists on a miniature scale in Prince Rupert's drops, (a suggestion 

 made by Mr. Naysmith at a recent meeting of the British Associa- 

 tion.) 



Admit the fragmentary character of meteorites, (which I conceive 

 must be done,) the force that detached it from any planet might with 

 equal propriety detach it from the moon ; while, from what is known 

 of that body, everything else would tend to strengthen this belief. 

 In the paper already mentioned as written by Mr. R. P. Greg, jr., 

 advocating the probable connexion between meteoric stones and the 

 group of asteroids, the author cannot altogether get over the probable 

 lunar origin of some of these stones, as will be seen from the follow- 

 ing quotation : 



" The physical constitution and internal appearance of some fiero- 

 lites, also, as those of Barbotan, Weston, Juvenas, and Bishopville, 

 are entirely opposed to the idea of an atmospheric origin, or of aiiy 

 consolidation of homologous or nebulous particles existing in the in- 

 terplanetary space. They are evidently parts, as Dr. Lawrence 

 Smith likewise justly insists on, of some larger whole, and are not un- 

 frequently true igneous if not volcanic rocks. Physically speaking, 

 there is little choice left us but to consider some of them certainly 

 as having true geological and mineralogical characteristics ; either 

 proceeding from volcanoes in the moon, or portions of a broken 

 satellite or planetary body : there may, indeed, be difficulties and ob- 

 jections to either supposition. I have principally endeavored to ad- 

 duce arguments in favor of the latter idea, stating also some appar- 

 ently strong objections to the (at least universal) lunar origin of 

 gereolites and meteoric iron masses." 



But it may be very reasonably asked, Why consider the moon the 

 source of these fragmentary masses called meteorites? May not 

 smaller bodies, either planets or satellites, as they pass by the eartli 

 and through our atmosphere, have portions detached by the niechani- 

 cal and chemical action to which they are subjected ? To this I will 

 assent as soon as the existence of that body or those bodies is proved. 

 Are we to suppose that each meteorite falling to the earth is thrown 



