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pl23_theb1762.jpg

Showing how line of sight clears recorder with inclined tripod

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https://www.noaa.gov/media/digital-library-photo/pl23theb1762jpg

Description

Showing how line of sight clears recorder with inclined tripod.Mechanized leveling with velocipede.Party of J. D. Crichton

Credit

C&GS; Season's Report Crichton 1920

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