GLACIERS. 139 



rt was not difficult to read in the immense deposit 

 over which I had walked whence came the suggestion 

 of dilatation to Scheuchzer, or of sliding to De Saussure ; 

 or, in the steady progress of knowledge and discovery, 

 the principles of action that are illustrated by the 

 terms tntrions and viscous and differential motion, as ap- 

 plied to the Alpine ice by eminent explorers of later 

 date. 



The subject of Greenland ice is one about which 

 there exists much popular misapprehension. As be- 

 fore stated, I do not here propose to enter into a 

 minute discussion of the manner of its formation and 

 movement, but will content myself with simply recog- 

 nizing the fact, and ^vith drawing such comparison as 

 may be needful between the mountain ice of Green- 

 land and similar deposits in other quarters of the 

 world. Under this head I trust that the reader may 

 find sufficient interest in the line of argument to fol- 

 low me through a few pages, in a general review of 

 the whole field. At a later period I will recur to some 

 more specific details of information and discussion, as 

 the narrative carries us to other objects of inquiry. 



In order to make the subject clear, I cannot do 

 better than to cite my Dlustrations from the region 

 of the Alps, where, through a long period, earnest 

 explorers have laboriously pursued their inquiries. 

 One of the most important and gifted of these was 

 M. Le Chanonie Rendu, Bishop of Annecy. This ex- 

 cellent and worthy man, and sincere devotee as well 

 of science as of religion, died some seven years ago. 

 A lifetime spent among the rugged crags and ice-clifis 

 of the Alpine Mountains had familiarized him with 

 every phase of Nature in that region of sublimity and 

 home of the wonderful. Professor Tyndall says truly 



