Note 89a — Chapter VII · GEOLOGICAL NOTES.
Reading edition
Mr. J. Cordeaux gives this thickness in the “Naturalist” (1897, p. 186). Professor J. Geikie says it “did not exceed 3,500ft. or 4,000ft. at most, and would take 3,000ft. as an average.” (“The Glacial Period and Earth Movement,” a paper read before the Victoria Institute in 1893. Trans. No. 104, pp. 221–249, where also the question is largely considered of the causes of the Ice-age).