204 LOUIS AGASSIZ. [CHAP. vm. 



fication of the glacier, the purity and composition of 

 the ice, the " crevasses," the temperature, the motion 

 of the glacier, the ablation, and the neve. Agassiz had 

 resolved to embody in a large publication, in three 

 parts, everything relating to the glacial system. The 

 first part, the only one ever published, was entitled 

 " Nouvelles etudes et experiences sur les glaciers 

 actuels, leur structure, leur progression, et leur action 

 physique sur le sol," and was accompanied by a beau- 

 tiful folio atlas, containing three maps and nine plates 

 (Paris, 1847). The second part was to be on the 

 " Alpine erratics," by Guyot. It was never written, 

 only a few general conclusions being published, without 

 maps of any sort. It is to be regretted, for Guyot had 

 prepared a map showing the distribution of the Alpine 

 boulders, which had not been published. However, a 

 great part of it more than two-thirds at least- -was 

 anticipated by the issue, in 1845, at Winterthur, of an 

 anonymous map of the old glaciers of the Swiss Alps, 

 showing the extent of the ancient glaciers of the Arve, 

 Rhone, Aar, Reuss, Linth, and Rhine, with their lateral 

 and frontal moraines. This map is entitled " Verbrei- 

 tungsweise der Alpen-fiindlinge," and its author is the 

 modest and very able geologist, Arnold Escher von der 

 Linth. Very likely the publication of this map dis- 

 couraged Guyot, who was always extremely slow and 

 timid ; and he resolved to publish neither the volume 

 advertised nor his map. As to the third and final part, 

 by Desor, treating of erratic phenomena outside of 

 Switzerland, it remained in the stage of contemplation, 

 and was never begun. 



