ANNIVEBSAEY ADDKBSS 03? THE PRESIDENT. IxXxix 



ing this digression, is it witliiii the range of physical possibility to 

 suppose that a mass of ice two or three miles in width should 

 have had the power of forcing onwards over an uneven bottom a 

 mass occupying a space of upwards of 3000 square miles, and 

 moreover of scooping ou.t a deep basin in the solid rock to a depth 

 of 900 feet ? Are we not rather forced to the conclusion that 

 this vast field of ice, closed in by mountain-ranges on every side, 

 must have been practically stationary, except in so far as the 

 gradual melting away of the ice at the south-western extremity 

 may have caused it gradually to have swelled out into the va- 

 cant space by the constant freezing of the infiltrating water, but 

 without exerting much, if any, grinding power ? Are we not also 

 forced to the conclusion that, if a certain amount of pressure from 

 above did cause the glaciers to descend the valley from the high 

 Alpine regions, this descending mass, or rather the upper portion 

 of it, on reaching the icy plateau of the plain, Avhich must have re- 

 sisted its pressure, would rather have flowed over the surface, and 

 have spread itself over the comparatively quiescent portion below ? 



With regard to this point, Prof. Eamsay says that he " cannot 

 conceive a horizontal fracture of forty miles in length over the 

 area of the Lake of Greneva, clearly dividing two bodies of ice, the 

 lower of which was when thickest nearly 1000 feet, and the upper 

 and sliding stratum must have been nearly 3000 feet thick." 

 Now I am not aware, I certainly have nowhere read, that any one 

 has ever propounded su.ch a doctrine, so contrary, as Prof. Ramsay 

 says, to all our knowledge of the motion of liquid or semiliquid 

 bodies. But, on the other hand, I have no doubt he Avill admit 

 that the motion of all parts of a liquid or semiliquid body is not 

 always equal. In the case of water, the most fluid of all liquids, 

 we know that the motion is not uniform in the flow of a river. 

 Near the banks, where there is friction, independently of other 

 opposing causes, the motion is less rapid than in the centre. 

 At the bottom, for the same reason, the motion is less rapid tlian 

 on the surface. And when we apply this argument to ice, a viscous 

 gelatinous body as Prof. Eamsay calls it, the less yielding nature 

 of which makes it more amenable to the laws of friction, we must 

 be all the more convinced that motion could not have been equal 

 throughout all its parts. There appears to me therefore no dif- 

 ficulty whatever in conceiving that while the upper portion of the 

 glacier may have been slowly moving forward, propelled perhaps 

 by the pressure of the more elevated glacier in the valley behind, 

 the lower portion, forming the bottom of the glacier resting on the 

 surface of the ground, may have been either absolutely quiescent, 

 or so nearly so, as to have produced no efi'ect Avhatever on the 

 rocky surface below ; not that this difference of motion was 

 caused by a horizontal fracture separating the moving from the 

 non-moving portion, but by a gradual diminution of motion act- 

 ing throughout the entire mass from the surface to the bottom. 



Thus I am at a loss to conceive where the force could come 

 from which could enable this gigantic glacier, spreading over the 



