A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2018 May 13, 11:36 -0700
Frank, you wrote: "Thinking about the view from the Moon would have been considered far too hypothetical and literally outlandish even fifty years ago".
Wrangel, in 1910 (2nd edition), in "Lärobok i teoretisk och praktisk navigation" wrote "parallax är den vinkel, varunder jordradien synes från en himmelskropp" or, in my translation, "parallax is the angle of the earth's radius as seen from a heavenly body".
That was written some 110 years ago. Wrangel was the standard work in Sweden during the first quarter or half of the 20th century.