Oecultations. 375 



on, in every direction, and through every kind of surface, a multi- 

 tude of eruptions, producingsmalldeepcratersresembling conical 

 wells, whose interiors are entirely free from all alluvial deposit. 

 Finally, in the intervals of these three great epochs, other 

 phsenomena are met with, which, M. Chacornac informs us, will 

 form the subject of a future communication. In conclusion, he 

 states his opinion that this great diluvium was probably due to 

 the precipitation of the gaseous matter of the lunar atmosphere; 

 the cooling of the globe having proceeded to a certain extent, 

 atmospheric pressure would favour the precipitation of gases 

 and vapours in the form of an universal rain, filling up the 

 great craters, and followed by a process of sedimentary conso- 

 lidation. 



It will be evident that an objection to this very ingenious 

 and striking selenological theory will be found in the sharp and 

 precipitous aspect of many of the great ancient rings, whose 

 angular relief ought to have suffered more serious degradation 

 from the loss of so much sedimentary matter as would have 

 been expended in filling up their interiors without external 

 communication. Plato and Archimedes may be cited as pro- 

 minent instances. It may be thought, too, that there is so 

 gradual a transition* from the broad flat ancient wall-plains to 

 the deeply-hollowed concavity of the more modern craters, 

 that it can scarcely be brought into accordance with the sup- 

 position of such clearly separable epochs ? Nevertheless, the 

 memoir is of so interesting a character, and proceeds from such 

 high authority, that we feel sure our readers will be glad to 

 have it placed before them, and will look forward with pleasure 

 to future communications from its eminent author. 



OCCULTATIONS. 



Dec. 3rd, 130 Tauri, 5h. 14m. to 5h. 38m.— 6th, A 2 Oancri, 

 8h. 12m. to 8k 48m. 



