PROCEEDINGS 
THE GEOLOGICAL SOCIETY OF LONDON. 
Vou. III. Part II. 1840—1841. No. 72, 
Nov. 4.—A paper was read on Glaciers, and the evidence of their 
having once existed in Scotland, Ireland, and England, by Professor 
Agassiz, of Neuchatel. 
M. Agassiz commences by observing, that the study of glaciers is 
not new, as Scheuchzer visited, and even drew, most of the glaciers 
of Switzerland; and as, at a later period, Gruner and De Saussure 
examined them in great detail, and left few of their phenomena 
uninvestigated. Hugi also, in his account of the Alps, and Scoresby, 
in his descriptions of the arctic regions, have communicated much 
valuable information respecting glaciers, but without giving rise 
to any important geological results. Venetz and De Charpentier 
first ascribed to the agency of glaciers, the transport of the erratic 
boulders of Switzerland, supposing that the Alps formerly attained 
a greater altitude than at present, and that the glaciers extended to 
the plains of Switzerland, and even to the Jura. This assumed 
greater height of the Alps M. Agassiz dissents from, as no geolo- 
gical phenomena compel him to admit it; and the arrangement of 
the boulders proves that the blocks were not pushed forward by the 
glaciers, as conjectured by M. de Charpentier. Moreover, the phe- 
nomena of erratic boulders extend over all the temperate and north- 
ern regions of Europe, Asia and America, and, consequently, could 
not depend upon so local an event as a greater altitude of the Alps. 
The consideration of these difficulties induced M. Agassiz to resume 
the study of glaciers; and after devoting the suitable portion of five 
successive summers to the study of their details, and all that has 
been written respecting their structure, he has arrived at the con- 
viction, that the formation of glaciers did not only depend upon the 
actual configuration of the globe, but was also connected with the 
last great geological changes in its surface, and with the extinction 
of the great mammifers which are now found in the polar ice. 
He is also convinced that the glaciers did not advance from the Alps. 
into the plains, but that they gradually withdrew towards the moun- 
tains from the plains which they once covered. In this belief, he says, 
he is supported by many considerations which escaped previous ob- 
servers, depending chiefly on the form and relative position of the 
erratic blocks, and the commonly called diluvial gravel, the former 
being in Switzerland always angular, and resting on the latter, 
which consists of rounded materials. Considered in this point of 
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