Heurtley magnifier suspension tube
date: label: date made
content: ca 1920
name: label: maker
content: Muirhead & Co. Ltd.
notes: label: Description (Brief)
content: A balance tube for a Heurtley magnifier suspension used in submarine telegraphy. A non-ferris tube with an adjustment knob on one end, a red-insulated wire emerging from both ends, a platinum resistance wire mounted axially within, and a second platinum resistance wire mounted above the tube. Unit is stored in a wooden box with catalog # 329939. No extant maker's marking on tube, various illegible markings on the box top. External wire is intact.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Western Union International
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.329923
label: catalog number
content: 329923
label: accession number
content: 283729
objectType: label: Object Name
content: Heurtley magnifier tube
label: Object Name
content: Submarine telegraph
label: Object Name
content: submarine telegraph component
physicalDescription: label: Measurements
content: tube: 1 in x 4 1/4 in x 5/8 in; 2.54 cm x 10.795 cm x 1.5875 cm
label: Measurements
content: box (closed): 1 1/2 in x 7 1/2 in x 5 in; 3.81 cm x 19.05 cm x 12.7 cm