Perry. ] 80 [February 28, 
§ 6. The Inception of the Ice-Sheet. 
There being some such kinds of preparation as those just men- 
tioned—there being an abundant supply of moisture, followed by a 
steadily increasing cold—snows would fall in winter, and gradually . 
waste less and less each succeeding summer. ‘This process continu- 
ing as the warm season became shorter and more fitful, the cold 
would finally be largely in the ascendant. In connection with these 
several circumstances, there being alternate thawings and freezings, 
the snows on the elevations might become adhesive, and not waste 
away; we should expect them slowly to change to névé, and this in 
due time to glacial ice. Masses of congealed moisture could thus 
begin to form in regions lying far to the north, and by slow degrees 
in those situated more to the south. These would at first remain all 
summer long only on the higher grounds. They might occur on 
most of the elevations properly situated for such results. At the 
outset they would doubtless be local. Probably they might be found 
in all the more elevated basin-shaped valleys with narrow outlets, 
usually separated from each other, one or more proceeding from 
very favorable height. And these inceptive glaciers would be char- 
‘acterized, and have their behavior determined according to the 
nature of the surface, the local conditions of heat and cold, and the 
various modifications in the working of the agencies operative in 
their production. Accordingly the fact of intense igneous activity 
near the close of the Tertiary period —— suggesting the occurrence of 
immense evaporation, and thus the source of abundant aqueous sup- 
ply, results which were no doubt of lone continuance — and the fact 
that a time of greater cold finally followed, probably occasioned by 
cosmical influences, afford sufficient occasion for the beginnings of an 
ice-sheet even in New England. Thus there may have been formed 
many ice-rivers, both far to the north, and more or less speedily in 
this neighborhood. ‘These, at first, might be somewhat isolated in 
their character, and flow in various directions. Those from the 
White Mountains perhaps moved toward every point of the compass; 
such as originated in the north-south mountain ranges, would extend, 
some westward, others toward the east, down the existing valleys 
and lines of depressions. Of course in connection with these srow- 
ing claciers there must have been the various phenomena appropri- 
ate to the conditions. Associated with most of them would be those 
processes and results usually occurring in the masses of like dimen- 
