is about 1,000° Fahr., for the latent heat augments as the
temperature of evaporation descends.

A pound of water thus vaporized at the equator has absorbed one
thousand times the quantity of heat which

[1. "The Great Ice Age," p. 98.]

{p. 60}

would raise a pound of the liquid one degree in temperature. . . . It
is perfectly manifest that by weakening the sun's action, either
through a defect of emission or by the steeping of the entire solar
system in space of a low temperature, _we should be cutting off the
glaciers at their source_."[1]

Mr. Croll says:

"Heat, to produce _evaporation_, is just as essential to the
accumulation of snow and ice as cold to produce condensation."[2]

Sir John Lubbock says:

"Paradoxical as it may appear, the primary cause of the Glacial epoch
may be, after all, _an elevation of the temperature in the tropics_,
causing a greater amount of evaporation in the equatorial regions,
and consequently a greater supply of the raw material of snow in the
temperate regions during the winter months."[3]

So necessary did it appear that heat must have come from some source