GLACIAL DRIFT. 337 
with water. Why should the former be so much and the latter so little 
oxidized? Relief came by examining the analyses. The blue clay con- 
tains more sesquioxide than the lower till, just as would be expected from 
the nature of the deposit. Furthermore, all blue protoxide clays have 
- come from deposition in water ;—hence there is nothing abnormal in be- 
lieving in the origin of the lower clay from the older till. 
OrvER oF EVENTS. 
The following list of occurrences expresses our most récent opinions 
respecting the order of events occurring in New Hampshire in the Gla- 
cial, Champlain, and subsequent periods : 
1. The country was covered presumably with forests of late Tertiary 
type, partly exhibited to us by the nearest fossils, yet of Eocene age, in 
Brandon, Vt. The beech, bass-wood, buckeye, Aristolochia, peperage, 
and cinnamon have been found there, with some others allied to the 
conifere. The change of climate induced by the change of land, com- 
bined with astronomical causes, would destroy most of these plants, and 
render the region sterile. Then the ice commenced to spread over New 
England, with alternate meltings of limited extent, so as to give rise to 
beds of sand and gravel. 
2. The ice accumulated in the St. Lawrence valley so as to flow over 
New England, possibly preceded by a south-west current. The whole 
country would have been covered by a sheet of ice, thousands of feet in 
thickness,—probably 7,000 or 8,000 feet in the lower part of the state, 
flowing south-east towards the ocean. This was the period of the forma- 
tion of the lower till, and of the great terminal moraines of lower New 
England. The broad sandy plains of Cape Cod and Long Island mark 
the beginning of the Champlain period. 
3. The melting of the ice has progressed steadily until no more ice is 
supplied from the St. Lawrence valley. New Hampshire is now covered 
by local glaciers, pushing down the Connecticut, the Merrimack, and 
other streams. The lower fossiliferous deposits of the coast are coeval 
with these glaciers. Variable seasons cause temporary advances and 
retreats of the ice, and thus allow of conditions favorable to the produc- 
tion of the inter-glacial beds. 
4. The thermal influences prevailing, the ice is driven back to the 
