Record. xxxix 



may well be proud of such a performance; their great liberality 

 towards science, and their appreciation of the rare value of 

 Agassiz, made it possible for him to prosecute with unimpaired 

 vigor his remarkable scientific researches famed the world over." 



In the summer of 1836 Agassiz made his first field studies of 

 glacial action in the formation and distribution of the drift and 

 in the transportation of bowlders, as exemplified in the great 

 valley of the Pthone. Under the able guidance of Ignace Venetz, 

 Ingenieur des Fonts et Chaussees in the Valais, and Jean de 

 Charpentier, Directeur des mines du Canton de Vaud, the summer 

 vacation, which he passed with his wife and child at Bex, was 

 spent largely in exploring the lateral and more distant valleys. 

 Opposed at first to the views of Venetz and de Charpentier, he 

 was quick to accept the proofs, and became an enthusiastic con- 

 vert. Returning to Neuchatel, he hastened to study anew the 

 polished surfaces of the rocks and the worn pebbles and erratic 

 bowlders on the slopes of the Jura. From these supplementary 

 observations his vivid scientific imagination evolved the original 

 and grand conception of a glacial epoch, in which present polar 

 conditions prevailed for an extended period over great conti- 

 nental areas which had previously teemed with life similar to 

 that which is now found only under the tropics. This vast con- 

 ception, true in essentials although not yet discussed entirely 

 apart from past and present conditions in the Alps, was pre- 

 sented in his presidential address delivered at the opening session 

 of the meeting of the Helvetic Society at Neuchatel, July 24, 

 1837. Received at first with incredulity by leading geologists 

 who had , sought to explain the phenomena of the drift by the 

 action of water and floating ice, both the glacial theory of 

 Venetz and de Charpentier and his own conception of an age of 

 ice at the close of the tertiary rapidly gained recognition, a rec- 

 ognition to which Agassiz contributed largely by his demonstra- 

 tion of past glacial action in Great Britain and Ireland, and later 

 by his field observations in the northern, central, and western 

 United States, on the northern shore of Lake Superior, and 

 in Brazil. On the ''Hassler" expedition (1872), in the Straits 

 of Magellan and in Smythe's Channel, he had the rare satis- 

 faction of studying both active glaciers and the vestiges of an 

 age of ice in the southern hemisphere. 



After 1837 Agassiz began to avail himself of the collaboration 

 of assistants in his work, thereby notably increasing the volume 

 of his publications. Critics have attempted, with more or less of 



