Note 13 — The General Proposition.[8]
Reading edition
The prime objection which is urged against all previous theories is their inadequacy. We here have a perfectly adequate cause—resident earth heat to supply evaporation and shut out solar energy, which energy can only act the part of a conservator of the glacial conditions until the exhaustion of earth heat, when its power can be spent in melting glacial ice, and in gradually establishing the present conditions.