Magnetometer
name: label: maker
content: T. Cooke & Sons Ltd.
notes: label: Description
content: This instrument, a lighter and more robust version of the standard unifilar magnetometer used at the Kew Observatory, was designed by H. A. Denholm Fraser for the Magnetic Survey of India. Features include scales graduated on optical glass, and a phosphor-bronze ribbon to suspend the magnet. This example is marked "T. COOKE & SONS LTD. LONDON & YORK. No. 26" and "U.S.C.& G.S. No. 40." It was used at the U.S. Coast and Geodetic Survey's magnetic observatory in Honolulu from 1927 to the 1950s. The U.S. Geological Survey acquired it in 1973, when it took over the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
label: Description
content: Thomas Cooke began in business in York, England, in 1837. The firm became T. Cooke & Sons in 1868, and T. Cooke & Sons Ltd. in 1897. A merger with Troughton & Simms Ltd. in 1922, led to the formation of Cooke, Troughton & Simms Ltd.
label: Description
content: Photograph 82-15291 shows this magnetometer fitted with the induction apparatus developed by J. H. Nelson in 1938.
label: Description
content: Ref: H. A. Denholm Fraser, "The Unifilar Magnetometer of the Magnetic Survey of India," <i>Terrestrial Magnetism</i> 6 (1901): 65-69.
label: Description
content: T. Cooke & Sons, <i>Illustrated Catalogue of Surveying Instruments, etc.</i> (London, 1907), pp. 62-63.</p> <p>Anita McConnell, <i>Instrument Makers to the World. A History of Cooke, Troughton & Simms</i> (York, 1992), pp. 69-70.
label: Location
content: Currently not on view
place: label: Place Made
content: United Kingdom: England, London
label: Place Made
content: United Kingdom: England, Jorvik
topic: label: Subject
content: Science & Scientific Instruments
label: Subject
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Science & Mathematics
label: See more items in
content: Measuring & Mapping
creditLine: label: Credit Line
content: U.S. Department of the Interior, U.S. Geological Survey
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1982.0671.02
label: accession number
content: 1982.0671
label: catalog number
content: 1982.0671.02
objectType: label: Object Name
content: magnetometer
physicalDescription: label: Physical Description
content: metal (overall material)
label: Physical Description
content: wood (part material)
label: Measurements
content: horizontal circle: 6 in; x 15.24 cm
label: Measurements
content: overall in case: 11 1/2 in x 22 1/8 in x 14 1/2 in; 29.21 cm x 56.1975 cm x 36.83 cm