1937 Citation for "Great Wall of China from Space" Myth

Urban legend buffs are familiar with the claim that the Great Wall of China can be seen from the Moon (or somewhere else in outer space). Nobody knows quite where this idea comes from.

I've just been reading One Man Caravan by Robert Edison Fulton, Jr. published in 1937 by Harcourt, Brace, and Company.

( Forty thousand miles on a motorcycle )