Siemens Galvanometer
date: label: date made
content: ca 1870
name: label: maker
content: Siemens Brothers & Co., Ltd.
notes: label: Description (Brief)
content: Round wooden base 8 in diameter; made in three pieces and set on three leveling screws; apparatus pivoted and revolving on base; slate disc, 6 1/2 in diameter and graduated, 0 to 140, on each side A & B, with German silver bridge wire set in the edge; movable arm carrying sliding contact with bridge wire; suspended astatic needle enclosed in round glass case 3 in diameter; 5 binding post connections, marked I II III IV V, and three resistance coils marked, 10, 100, 1000. Marked, Siemens Brothers, London, No. 780. Suspension fibre missing. This form of galvanometer was introduced into this country about 1870 and for ten or fifteen years was extensively used in testing telegraph lines, etc., et.,. Exhibition label: "This instrument was used extensively as a sine galvanometer and as a Wheatstone bridge in testing early telegraph lines."
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Michigan Central Railroad Co.
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.209870
label: catalog number
content: 209870
label: accession number
content: 37861
objectType: label: Object Name
content: Galvanometer
label: Other Terms
content: Galvanometer; Measuring Devices