178 The America?i Geologist. Septomboi-, i899 
of cloud condensation. The princiijal function of exterior 
heat, prior to the chilHng of the oceans, being conservative 
or to replace in part the heat lost by radiation from the cold 
outer surface of the cloud sphere. 
(5) That until the exhaustion of the available internal heat 
supply, outside of a crust of low conductive power, the surface 
temperatures of the spheroid must be nearly uniform from 
pole to pole, varying only with elevation above sea level, or 
from local causes, such as the influence of lava outbursts upon 
the areas to the leeward of such outbursts. And that a series 
of uniform climates must prevail independent of latitude, and 
gradually decreasing in temperature as the spheroid loses 
heat. 
(6) That the low specific heat of land areas permits them 
to cool more rapidly and to reach glacial temperatures before 
the oceans are reduced approximately to the point of maxi- 
mum density, and consequently that snow must accumulate 
upon these areas until the oceans cease to give ofT sufficient 
vapor to shield the earth from solar energy. That these ac- 
cumulations of snow must reach their maxima along belts 
of maximum precipitation, and must be independent of lati- 
tude. 
(7) That upon the chilling of the oceans, the supply of 
vapor maintaining the cloud envelope is cut ofT, and the at- 
mosphere deprived of the greater portion of its heat intercept- 
ing power; and that heat rays from exterior sources then reach 
the planetary surface in sufficient quantity to dominate its cli- 
mates. That a new distribution of temperatures is thereby 
inaugurated dependent principally upon latitude or exposure 
to exterior sources, and modified by elevation and local causes. 
(8) That solar rays by contact with planetary surface are 
partly converted into dark or obscure rays and are trapped,* 
or are selectively absorbed.! That a gradual accession of 
heat must be thereby inaugurated, resulting in the removal of 
glacial conditions and that such removal of glacial conditions 
must be on lines determined by the degree of exposure to 
*Tyndall— Proc. Royal Soc, Vol. XIII, p. 160. Phil. Trans., Vol. 
152. p. 95. Archives des Sciences, torn. V., p. 29.3. 
tLangley — Investigations on the Action of the Atmosphere on Solar 
Radiation. Mem. Nat. Academy of Sciences, 1885-7. 
Buf¥ — Archives des Sciences, torn. LVII, p. 293. 
