William J. Peters of the U. S. Geological Survey devised this type of instrument in 1898, while doing reconnaissance work in Alaska. G. N. Saegmuller, proprietor of Fauth & Co., explained its function: "Having a fixed base of known dimensions defined by targets, the measurement is made by bringing the images of the targets together by moving the halved objective by means of a micrometer screw." The Geological Survey transferred this example to the Smithsonian in 1907, reporting that "Distances up to 1 or 2 miles can be determined with sufficient accuracy for reconnaissance work."

This is actually a composite instrument. The prism monocular was probably made by Bausch & Lomb in Rochester, N.Y., according to the design developed by Zeiss in Jena, Germany, while Saegmuller made the divided object glass micrometer. It is notably different from the stenometer that Saegmuller was offering in 1901, and so is probably an early prototype. The words "U.S.G.S. No. 4" are scratched onto its surface.

Ref: George N. Saegmuller, Descriptive Price-List of First-Class Engineering & Astronomical Instruments (Washington, D.C., 1901), p. 108.

Maker: Fauth & Co.

Location: Currently not on view

Place Made: United States: District of Columbia, Washington

See more items in: Medicine and Science: Physical Sciences, Surveying and Geodesy, Measuring & Mapping


Exhibition Location:

Credit Line: U.S. Geological Survey

Data Source: National Museum of American History

Id Number: PH.247921Catalog Number: 247921Accession Number: 47736

Object Name: Stenometer

Measurements: overall: 2 in x 3 1/4 in x 4 3/4 in; 5.08 cm x 8.255 cm x 12.065 cmoverall: 2 in x 3 5/16 in x 4 11/16 in; 5.08 cm x 8.41375 cm x 11.90625 cm


Record Id: nmah_761895

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