~~ 
1884. 93 Trans. N. Y. Ac. Sci. 
if the conditions as to elevation continued to the north of us, it would 
not be necessary to go far to find perpetual snow. For snow once fallen 
or ice once formed, would never melt, but, accumulating through the 
ages, would force its way south by its own weight, until it reached so 
far below the true snow line as to be melted. 
Such uplifts to-day, the atmosphere remaining as it is, and the 
earth’s axis again becoming perpendicular, would bring back the 
Glacial epoch. 
The warmth of the Champlain was due to a reversal of these con- 
ditions. From some cause the axis had attained its present obliquity, 
this of itself rendering the climate of polar regions more genial, 
while the depression of the land below its present level, and the con- 
sequent extension of ocean surface, greatly aided and accelerated the 
result. 
A moderate and comparatively local uplift, mostly confined to the 
eastern continent, would account for the minor Glacial period which 
seems almost confined to that part of the world. 
Subsequent changes of elevation left us the climate of to-day. 
SUMMARY. 
1. The early warmth was due to the ‘‘ blanket” of carbonic acid, 
aqueous vapors, and probably other gases and vapors. 
2. The uniformity—lack of seasonal changes, and the equality of 
light and actinic force—was due to the axis of the earth being nearly 
or quite perpendicular. 
3. The slow fall of temperature at first, the more rapid fall in later 
times, and the cold of the Glacial epoch, were due to the gradual puri- 
fication of the atmosphere, and, with reference to the cold, to great 
high latitude uplifts. 
4. The return of warmth was due to increased obliquity of axis, and 
to high latitude depression of the land and consequent extension of 
the ocean. 
5. The Champlain warmth was due to the extreme depression. 
6. The minor Glacial epoch was due to comparatively sudden and 
local elevation. 
7. Present climate is due to present arrangement of land and water 
and to the introduction of seasons, or, in other words, to the present re- 
lation of day and night. 
The influence of vapors and gases on climate was pointed out by 
Prof. TYNDALL andothers. Several have proposed a change of incli- 
nation or of geographical position, as a solution of the climatic problem. 
DANA and others have spoken of the high latitude uplifts and the sub- 
sequent depression. The theory in this paper weaves all these and 
