Glacial Geology in America, — Fairchild. 159 
jections to the glacial origin of the drift were to them conclu- 
sive. They were unable to apply to the broad plateaus of 
northeastern America the work of local or alpine glaciers. 
How could ice flow up hill? The glaciers of the Alps ah 
moved down the slopes. How could an ice mass move over 
even comparatively level tracts? Indeed, Dana did not ans- 
wer this difificulty until the 1879 edition of his Manual. The 
prevailing southerly direction of the drift movement, with only 
minor deflections by mountain masses or great valleys, did not 
harmonize with conceptions derived from written descriptions 
of the glaciers of the Alps, and they were not prepared to 
grasp Agassiz's idea of a great circumpolar ice sheet. The 
very large proportion of water-worn or water-laid materials 
in the drift certamly favored aqueous agency. 
But there were other antagonistic forces which were not of 
a scientific character. Agassiz was a comparative young man 
and quite unknown in geology except for his study of glaciers. 
How could his opinion weigh against those of the giants in 
geology? xA.nother power, which will scarcely appear in the 
scientific writings of the time, but which was a great conserva- 
tive force, was theological opinion. All hypotheses invoking 
water as the drift agency might be harmonized with belief in 
the Noachian deluge, but the Bible gave no comitenance to 
an ice deluge. The "diluvium" was an ever present evidence 
of the truth of the deluge. To explain it away was little better 
than heresy. In these days of liberty of thought it is not pos- 
sible for us to realize the repressive power of religious opin- 
ion in Puritan New England. Furthermore the diluvial hy- 
potheses were unduly deductive, and like all op.nicns not bastd 
on observational or inductive evidence did not readily yield 
to the arguments derived from facts. The older geologists had 
made up their minds and that settled it. Tliey were also most- 
ly committed in print to some form of the diluvial idea. Those 
early classics in American geology, the state reports of New 
York, Massachusetts and New Hampshire, anpeared during 
the years 1841-1844, and by generally referring the drift to 
a(|ueous origin helped to fix opinion along diluvial lines. Ik'- 
fore leaving this subject it will be well to state briefly the na- 
ture of some of the theories of the drift. 
Edward Hitchcock had written the deologv of .Massachu- 
