MEMOIR OF GUYOT. 703 



of seeing men of cultivation of all classes in Xeuchatel pressing into 

 the large ball of the college and listening to him with riveted attention." 

 His pupil adds: " What zeal he inspired ! what ardor for work! The 

 fire with which he was filled passed to us. He was more than a pro- 

 fessor; he was a devoted friend, a wise counselor, associating himself 

 with us and encouraging us in our work." 



Guyot, besides lecturing and instructing, did all he could of outside 

 work — meteorological, barometric, hydrographic, orographic, and 

 glacialistic. The'hydrographic work was the careful sounding of Lake 

 Keuchatel (in all eleven hundred soundings) as the commencement of 

 a study of the annual variation in the temperature of the waters of the 

 Swiss lakes. His chief research — that on the distribution of the bowl- 

 ders or erratics over Switzerland — occupied him, "single-handed, seven 

 laborious summers, from 1840 to 1847," he allowing himself only, "at the 

 end of his working season, the pleasure of a visit of a few days to the 

 lively band of friends established on the Glacier of the Aar, in order to 

 learn the results of their doings and communicate his own to them."* 

 Switzerland in the ice period was his subject; and the sources of the 

 bowlders and the courses of ice transportation were the chief inquiries. 

 The investigation involved excursions on foot and careful examination 

 of the whole range of the Swiss Alps, the slopes into Italy, the plains 

 of Switzerland, and the mountains on the northern and western borders, 

 including the Juras — in all an area of 190 by 310 miles — in order to 

 trace the erratics to their high sources among the snowy summits, ex- 

 amine the rocks of all peaks, ridges, and valleys for comparison with 

 those of the erratics, measure the heights along the lines and limits of 

 the erratics from plain to mountain peak, and note all glacial markings. 

 The task was accomplished with the greatest possible fidelity; " thou- 

 sands of barometric measurements" were made in the course of it, and 

 between five and six thousand specimens were gathered in duplicate. 



Thus, says Guyot, " Eight erratic basins were recognized on the 

 northern slope of the Alps — those of the Isere, the Arve, Rhone, Aar, 

 Eeuss, Limmat, Sentis, and Rhine ; and four on the southern slope — 

 that of the Adda, including LakeComo, of Lugano, of Ticino, including 

 L. Maggiore, and that of the Val d'Aosta. 



"Moreover, a question left hitherto untouched — the distribution in 

 each basin of the rocks special to it — was minutely examined, and the 

 final results of all the laws observed in the arrangement of the erratic 

 fragments were shown to be identical with the laws of the moraines. 

 This identity, and the absolute continuity of the erratic phenomena 

 from the heart of the Alps down the valleys and beyond to the Jura 

 left no alternative but to admit the ancient existence of mighty glaciers 

 as vast as the erratic regions themselves, and having a thickness of 

 over 2,000 feet." 



Brief notes on his work were published in the Bulletin of the Neuchatel 



*Memoir of Agassiz. (Biographical Memoirs, II, p. 67.) 



