Smithsonian - National Museum of American History, Behring Center

 
Physical Sciences Collection - Surveying and Geodesy

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Gradienter - click to enlarge

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Gradienter

Catalogue number:
PH*247907

Inscriptions:
"Geo. ShillingWashn D.C." and "U.S.G.S. No 4"

Dimensions:
horizontal circle 4.25 inches diameter; telescope 9.5 inches long

Discussion:

This instrument was made after 1882 when George Shilling began in business, and before 1907 when the United States Geological Survey transferred it to the Smithsonian. The horizontal circle and vertical arc are silvered, graduated to 30 minutes, and read by verniers to single minutes. A level vial sits atop the telescope; a circular level sits on the horizontal circle, obscuring most of Shilling's signature.

Further Information:

Shilling
Gradienter

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