Galvanometer

Physics

Accession Number: 2009.ph.197

Description:

This artifact has a circular bakelite base with three knurled brass leveling screws as feet. On the top of the base there are 3 brass terminals and a brass cylindrical casing. The brass cylindrical casing has a tube approximately 13 cm tall sticking vertically out the casing. In front of the tube on the cylindrical casing there is a flat glass window with a small circular mirror on the other side of the window. Engraved on the side of the base some white lettering, worn away, reads: “LINK IN APERIODIC”, and “LINK OUT BALLISTIC”.

Carved on the rear of the bakelite base it reads: “III E”

Alternative Name:

Primary Materials: Metal, glass

Markings:

Engraved on the side of the base: “H. TINSLEY & Co LONDON. S.E. No12777”.

Scratched into the bakelite base: “III E”

Dimensions (cm): Height = 26, Diameter = 16.5

Function:

This galvanometer measures slight changes in electrical current. An electrical current introduced to a coil turns the coil relative to a large permanent magnet. This in turn rotates a small hanging mirror. Light reflected off this mirror onto a distance scale can be read as indicating greater or smaller changes in current.

Condition:

Very good: The instrument is in good condition, with all its parts intact. It is somewhat corroded on the surface, particularly on the various knurled knobs of the instrument. The words on the bakelite base are partly worn away, particularly on the right hand side.

Associated Instruments:

Manufacturer: H. Tinsley & Co, London

Date of Manufacture:

Provenance: Dr. Martin Lee’s Collection

Historical Notes: