Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Surveying and Geodesy

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Theodolite - click to enlarge

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Catalogue number:

"Eckhold's Patent Omnimeter, No 26" and "Elliott Bros LONDON"

height 15.25 inches; horizontal circle 5.375 inches diameter; needle 4.5 inches; vertical circle 5.375 inches diameter; telescope 13 inches long

Charles A. C. Eckhold, a German engineer living in Alexandria, obtained a British patent for the omnimeter in 1868. Contemporary accounts term it an "important surveying instrument," noting that it "measures distances and altitudes with an extraordinary degree of accuracy and great economy of time and labor; it accomplishes, without being moved, the work of Theodolite, Level, and Chain, and may be used as an ordinary Theodolite." The key feature of the Omnimeter is a tangential scale located across the horizontal circle that is read by a telescope mounted perpendicularly to the main telescope. This example was made by Elliott Brothers, a London firm that offered a wide range of instruments. It belonged to George Shattuck Morison (1842-1903), a prominent American engineer and bridge builder. The horizontal circle is silvered, beveled, graduated to 30 minutes, and ready by opposite verniers to single minutes. The vertical circle is silvered, graduated to 30 minutes, and read by opposite verniers and magnifiers to single minutes.

Ref: "Distances" in [Edward Spon], Spons' Dictionary of Engineering, Civil, Mechanical, Military, and Naval (London, 1872), pp. 1210-1214.

Eckhold's Patent Omnimeter, Manufactured by Elliott Brothers (London, n.d.)

"George Shattuck Morison," Civil Engineering 8 (1938): 288-289.

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