The Evolution of Clhnates. — Manson. i6i 
by radiation from its upper surface into space. This vapor 
would then condense, and as rain, snow or hail, descend all, or 
part of the way, to the earth, receive another increment of heat 
and ascend as before — a slow process, but exhaustive in time, 
although retarded by the conservative action of exterior heat 
sources. 
Thus the property of water to assume three forms, each of 
which possesses remarkable qualities with regard to heat and 
cold, afforded the principal means for exhausting the earth 
heat. As vapor, it possesses with one exception* the prop- 
erty of storing more heat than any other known substance, 
and of being, when partly condensed, the most non-transcalent 
substance known; the high specific heat of water, in the shape 
of clouds or fogs largely prevents heat from passing until the 
minute vescicles are expanded into invisible vapor. 
As a fluid, it possesses the highest specific heat of any 
substance composing the crust of the earth; and as snow or 
ice it possesses the property of storing more cold than any 
other known substance. 
Clouds being more translucent than transcalent, light rays 
reached the planetary surface more readily than heat rays. 
The earth may thus be regarded as having been surrounded 
by a series of spheroidal isothermal surfaces of mean tempera- 
tures. The one next the surface represented a mean tempera- 
ture of say boiling water at a temperature corresponding to 
the greater pressure of the heavier atmosphere existing. 
Above this isothermal shell were others representing mean 
temperatures of 200°, 90°, 60°, 32°, zero, etc., to — x° Fahr., 
the extreme cold of interplanetary space. 
Between the two spheroidal isotherms of 32° and — x"" 
Fahr., was one which had a mean temperature of 32° — y°, and 
equally exposed to both sources of heat. 
That the spheroidal of 32° Fahr., was within the sphere of 
influence of earth heat, is proven by the formation of snow 
or ice at that temperature, both being the resultant of vapor 
expanded and raised by earth heat to that hight as a min- 
imum. Moreover, vapor would have reached that hight as a 
minimum were solar and stellar heat suspended for a definite 
period, and the earth absolutely exposed to loss by radiation 
*Hydrogen. 
