astatic galvanometer with moving magnets
Date1870-1890
Inventory Number0234
ClassificationAstatic Galvanometer
Subject
Maker
Elliott Brothers
1853 - 1916
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Origin
Place of Use
Dimensions55 × 25.5 × 25.5 cm (21 5/8 × 10 1/16 × 10 1/16 in.)
Material
DescriptionGalvanometer with pair of movable magnets within a pair of coils mounted one above the other and supported on two short brass columnar posts. Encased in cylindrical glass case with brass top. A vertical rod set in top of case supports a slightly curved bar magnet for zero adjustment by worm drive. Circular bakelite base with three leveling screws and four binding posts.
Signedon upper coil: Elliott Bros. / London / No. 123
Inscribedmarked on base: E.M.
Curatorial RemarksPaper tag formerly on instrument incorrectly labeled the instrument as "232".
FunctionThis galvanometer was used in classroom demonstrations. An astatic galvanometer is a sensitive instrument that measures small current displacements. When an electric current passes through a wire coil, it induces a magnetic field that causes the coil to rotate in proportion to the current deflections, twisting a suspended magnet. The current deflections can be detected using a scale.
For more on astatic galvanometers, see the following website.
For more on astatic galvanometers, see the following website.
ProvenanceFrom Department of Physics, Jefferson Laboratory, Harvard University, 1/8/1957.
Elliott Brothers
Date: circa 1930
Object number: 0232
American
Date: circa 1915
Accessories: Extra case of coils and extra set of magnets (0154d). Three extra magnets (3 bar magnets and 2 bar magnets attached to an aluminum wire) are not numbered because of size.
Object number: 0154a,b,c
