Bryan Gravimeter

Gravimeters (gravity meters) are extremely precise instruments that measure the earth’s gravity at a specific location. Gravimeters are often used by prospectors to locate subterranean deposits of valuable natural resources (mainly petroleum) as well as by geodesists to study the shape of the earth and its gravitational field. Differences in topography, latitude, or elevation—as well as differences in subterranean density—all affect the force of gravity. Commonly, gravimeters are composed of a weight hanging on a zero-length spring inside a metal housing to negate the influence of temperature and wind. Gravity is then measured by how much the weight stretches the spring.
This gravimeter was built in 1938 under the direction of Andrew Bonnell Bryan (1897 1989), a Ph.D. physicist who served as Director of the Geophysics Division of the Carter Oil Co., in Tulsa, Oklahoma. Bryan described an earlier model at the 1937 meeting of the Society of Exploration Geophysicists, noting that it "was originally designed in the laboratories of the Humble Oil & Refining Company and is now being built and used by both Humble and Carter in slightly different forms." The gravimeter weighed 112 pounds, and could be "readily handled by two men." The Carter Oil Co. donated this instrument to the Smithsonian in 1959.
Ref: F. G. Boucher to P. W. Bishop, August 6, 1959, in NMAH accession file.
A. B. Bryan, "Gravimeter Design and Operation," Geophysics 2 (1937): 301-308.
Currently not on view
date made
Carter Oil Company
place made
United States: Oklahoma, Tulsa
overall: 44 cm x 27.5 cm x 30 cm; 17 5/16 in x 10 13/16 in x 11 13/16 in
overall: 43 in x 32 in x 33 in; 109.22 cm x 81.28 cm x 83.82 cm
ID Number
catalog number
accession number
Credit Line
Carter Oil Company and Jersy Production Research Company
See more items in
Work and Industry: Agriculture and Natural Resources
Measuring & Mapping
Natural Resources
Data Source
National Museum of American History


Add a comment about this object