GLACIAL PERIOD. 
I N the early part of the summer of 1840, 
I started from Switzerland for England 
with the express object of finding traces of 
glaciers in Great Britain. This glacier-liunt 
was at that time a somewhat perilous under¬ 
taking for the reputation of a young naturalist 
like myself, since some of the greatest names 
in science were arrayed against the novel 
glacial theory. It was not strange that it 
should be at first discredited by the scientific 
world, for hitherto all the investigations of 
geologists had gone to show that a degree 
of heat far greater than any now prevailing 
characterized the earlier periods of the world’s 
history. Even Charpentier, my precursor and 
master in glacial research, who first showed 
the greater extent of Swiss glaciers in former 
times, had not thought of any more general 
application of his result, or connected their 
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