Signedon plaque on case: WESTON / REFLECTING GALVANOMETER / MADE BY THE / WESTON ELECTRICAL INSTRUMENT CO. / NEWARK, N.J. U.S.A. / MODEL 89 No 45
Inscribedon plaque on case (serial number): MODEL 89 No 45
FunctionA reflecting 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 and mirror. The current deflections can be detected using a light beam that reflects off the mirror and onto a scale.
Historical AttributesThis instrument was one of a small lot made under the personal supervision of Mr. Weston. It is claimed that he supervised the feeding of the silk worms which furnished the sil threads for insulating the wires so as not to contain any magnetic material. Two of these instruments were given to Harvard by Mr. Weston and some to other colleges. This was one of the last instruments Mr. Weston worked on personally.
ProvenanceFrom the Department of Physics, Harvard University, 10/30/1968.