202 Rev. H. Moseley on the Mechanical Possibility [Jan. 7 , 



near the "Tour de Juvillac." A figure of the working-surface of the teeth 

 of the lower jaw from this locality is given (of the natural size), showing 

 the characters of the canine and proportions of the diastema. The close 

 conformity in the characters of the upper grinders of the Puy-de-D6me 

 fossils of deposit with those of the Bruniquel cavern enables the author to 

 dispense with figures of them. 



The sum of the several comparisons is to refer the above Equine fos- 

 sils from sedimentary deposits and both varieties from the Bruniquel 

 cave to one and the same species or well-marked race belonging to the 

 true Horses, or restricted genus Equus of modern mammalogists ; the in- 

 dividuals of which race, with a small range of size, probably due to sex, 

 were less than the average-sized horse of the present period, but larger 

 than known existing striped or unstriped species of Asinus, Gray. 



Interesting testimony, confirmatory of the conclusion from the palseon- 

 tological comparisons, is adduced from outlines of the heads of different in- 

 dividuals of the Cave Equine when alive, neatly cut on the smooth sur- 

 face of a rib of the same species, discovered by the Vicomte de Lastic St. 

 Jal in 1863, in his cavern at Bruniquel, under circumstances which indis- 

 putably showed the work to have been done by one of the tribe of men 

 inhabiting the cavern and slaying the wild horses of that locality and 

 period for food. 



The author remarks that every bone of the Horse's skeleton (and such 

 evidence had been obtained from about a hundred individuals that had been 

 exhumed at the period of his second visit to Bruniquel, in February 1864) 

 had been split or fractured to gain access to the marrow. The dental canal 

 and roots of the teeth had been similarly exposed in every specimen of 

 jaw. 



II. u On the Mechanical Possibility of the Descent of Glaciers, by their 

 Weight only/' By the Rev. Henry Moseley, M.A., Canon of 

 Bristol, F.R.S., Instit. Imp. Sc. Paris, Corresp. Received Oc- 

 tober 21, 1868. 



(Abstract.) 



All the parts of a glacier do not descend with a common motion ; it 

 moves faster at its surface than deeper down, and at the centre of its sur- 

 face than at its edges. It does not only come down bodily, but with dif- 

 ferent motions of its different parts ; so that if a transverse section were 

 made through it, the ice would be found to be moving differently at every 

 point of that section. 



This fact*, which appears first to have been made known by M. Rendu, 



* The remains of the guides, lost in 1820 in Dr. Hamel's attempt to ascend Mont 

 Blanc, were found imbedded in the ice of the Glacier des Bossons in 1863. "The men 

 and their things were torn to pieces, and widely separated by many feet. All around 

 them the ice was covered in every direction for twenty or thirty feet with the hair of one 

 knapsack, spread over an area three or four hundred times greater than that of the knap- 



