A. WincheU on ^Pressure of a Continental Glacier- 141 
Conte at not less than 150,000 square miles, with a thickness of 
three to four thousand feet. The Columbia river at the Cascade 
Range, has cut through 2,500 to 3,800 feet of lava. 
Heretofore the epoch of the outflows has been placed late in 
the Pliocene — before the Glacial epoch. On this assumption, 
American man has been located in the Pliocene, since his re- 
mains have been found in California beneath the great sheet of 
lava which caps the celebrateJ Table mountain of Calaveras 
county. The relation here suggested, but hitherto overlooked 
between western lava outflows and eastern ice-pressure has 
therefore, the ulterior effect of reducing the supposed antiquity 
of man in America, and thus of harmonizing his chronology 
with that of European man. 
This conclusion is indicated on other grounds. Remains of 
man have been found associated with Equiis occidentalis and 
E. excelsus Leidy, in Oregon, in beds held by Cope and Marsh, 
it is true, to be Pliocene; and a similar association is reported 
from Colorado by Dr. Gilbert. The account of these observa- 
tions has not yet been published ; but from personal informa- 
tion from Dr. Gilbert, I learn that he and Mr. Mc Gee connect 
the Equus fauna of Oregon with the Glacial epoch rather than 
the Pliocene; and this result is in accord with what I anticipated 
on theory, may be found to be the truth in California, in re- 
spect to the gravel beds holding hvnnan remains underneath 
tables of lava. 
This method of viewing the subject of continental glaciation 
leads to another suggestion. If the terrestrial crust, to the east 
of the Rocky mountains and north of the Ohio river, was 
deeply indented by the weight of a sheet of ice say five thousand 
feet thick, a change must have resulted in relative levels of land 
and sea in the regions contiguous to the ice-boundary. The 
crustal depression would not be limited strictly to the ice-covered 
area. The crust's partial rigidity w^ould cause the depression to 
be experienced along a bordering belt many miles in width. 
That is, the original Atlantic border of Labrador and New 
England would be depressed, and so would a belt through New 
Jersey, Maryland, Kentucky and Illinois lying along the south- 
ern limits of the glacier. 
Along shores reached by the glacier, the ocean would bathe 
