overall: 55 cm x 30 cm x 31 cm; 21 21/32 in x 11 13/16 in x 12 7/32 in
Object Name:
gravity meter, Humble Model Y
Description:
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.
The Humble Oil and Refining Co. built a succession of gravimeters. This one is a "Type Y" and probably dates from the early 1940s. It came to the Smithsonian in 1963. The accession memorandum terms it a "Gravity Meter Model." The bill of lading describes it as "1 Gravimeter display in wooden box (advertising)" and gives its weight as "800 lbs. approx."
