﻿Canon Moseley on the Descent of Glaciers. 363 



fOC 2 H 5 

 Na"^ C 2 H 3 



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The large amount of heat evolved during the formation of these 

 compounds proves them to be genuine cases of chemical combi- 

 nation, and not merely instances of juxtaposition of molecules. 



LI. On the Mechanical Impossibility of the Descent of Glaciers 

 by their Weight only. By Henry Moseley, M.A., Canon of 

 Bristol, F.R.S., Instil. Imp. Sc. Paris, Corresp* 



THE following is the mathematical discussion of the condi- 

 tions of the descent of a glacier of unlimited length and 

 uniform rectangular section and slope, from which I have de- 

 duced the conclusion that it is mechanically impossible the Mer 

 de Glace should descend as it does by its weight only, in a paper 

 of which an abstract was read before the Royal Society on the 7th 

 of January, and published in the Proceedings of the Society and 

 in your Magazine for March. 



Let ABCD represent part of the surface of a glacier of 



uniform slope and uniform width and depth, AD being a por- 

 tion of the central line of the surface, and B C of the edge, and 

 A B at right angles to AD and B C. Also let abed be a part 

 of the floor of the glacier, and ABka section perpendicular to 

 the floor and the surface of the glacier and to the direction of its 

 motion, and let AadD and BbcC be planes perpendicular to 

 the surface and floor, but parallel to the direction of the motion 

 of the glacier. Let A D be the space traversed by a particle in 

 the central line of the surface in any given time, B C that de- 

 scribed by a particle in the edge of the surface in the same time, 

 and a d and b c spaces similarly described by points in the centre 

 and edge of the bottom of the glacier. Imagine the trapezoidal 

 solid Ac to be intersected by an infinite number of planes pa- 



* Communicated by the Author. 



