Note 2 — Introduction.
Reading edition
N. S. Vol. XXIII, No. 588, p. 551-555, April 6, 1906. Reprinted in the Seattle Post Intelligencer for March, 1906, the Scientific American Supplement, Vol. LXII, No. 1602, September 15, 1906, and in the Washington Magazine, Vol. I, No. 4, June 1906. Abstracted in the Bulletin of the American Geographical Society, May, 1906.