Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Surveying and Geodesy

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Locke Level - click to enlarge

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Locke Level

Catalogue number:

7.75 inches long


John Locke, a physician and scientist in Cincinnati, Ohio, described a reflecting level at a meeting of American geologists and naturalists in 1842, and obtained a patent (#7,477) in 1850. Locke's instrument consists of a small spirit level on a brass sighting tube, with a small diagonal reflector so arranged that the user can see the bubble and a distant sight at the same time. This simple and perhaps homemade Locke level belonged to the Anglo-American physician and scientist, William Draper (1811-1882), or one of his descendants.

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