172 FfocecduKjs uf /he Roijal Sockly. 



the onward movement of the glacier leaving narrow spaces interven- 

 ing between the sides of the already formed icy mass and the flanks 

 of the valley, which, being filled up with the loose and softened 

 snow lying on the sloping flanks, was, from tlie falling of the tem- 

 perature during the night, and from contact with the already formed 

 icy mass, converted into a layer of solid ice. From the thinness of 

 these layers, the author regaitled them as marking the additions 

 which had been daily made to the glacier. The author also stated 

 that it would, in all probability, be found that, wherever pillars, pyra- 

 mids, or needles of ice were met with, this structure would be found 

 present ; as the fissures which always crossed the glacier from side 

 to side, divided it into transverse sections, which, when unequally 

 supported below, would split into smaller fragments in the planes of 

 their stratification, so that each fragment would necessarily assume 

 the form of a vertical prismatic column. 



3. A covibination of the Horizontal ivlth the Vertical and Lon- 

 gitudinal Strata. The author stated, that, as the mass composed of 

 the horizontal strata of the upper regions slowly advanced to the 

 lower ones, it received, in the manner above stated, a lateral increase, 

 which, at the same time that it increased its breiidth, probably also 

 added to its depth. That; as the glacier continued to advance, tho 

 horizontal strata, 'which lay uppermost, would melt away first, so 

 that at one point they would only be observed in the middle of the 

 glacier, and lower doAvn even completely disappear. He mentioned 

 several facts which seemed to prove his position. 



4, Transverse more or less inclined Strata. The author stated 

 that this variety of stratification had not been recognised as a dis- 

 tinct form, but had been confounded with the horizontal stratifica- 

 tion. He stated that this form would only be met with when the 

 original structure of the glacier had been broken up and destroyed 

 by some obstructing barrier or other cause. He instanced as the 

 most marked example of this tlje terminal portion of the Rhone 

 glacier, after it pours into the valley of the Rhone over its rocky 

 barrier or precipice. He described the strata as being formed close 

 to the icy mass on which the icy cataract descends, originally paral- 

 lel to each other, and with a dip of 70° ; but that, as new layers 

 are formed, and the first formed layers are pushed forwards, they 

 lose their parallelism to each other, and assume angles of dip less 

 and less as they approach the termination of the glacier. This 



