Muirhead "Apex box" for submarine telegraph line
date: label: date made
content: ca 1920
name: label: maker
content: Muirhead & Co. Ltd.
notes: label: Description (Brief)
content: Submarine Telegraph Apex Box. This is a "1/4 ohm rheostat" used in an Muirhead double-block system along with other components including an artificial line. A hard rubber base on which is set three binding posts, two connector blocks (connectors missing), and a glass-topped brass cylinder containing a sweep switch and 41 contacts. Removable adjusting knob on top. Marked on base: "Muirhead & Co. Ltd Westminster / Index / Shunt / 10 Ohms / No. 34281"; on switch plate: "Quarter Ohms". Reference: Duncan H. Cameron, Submarine Telegraphy, International Textbook Company, 1927, pages 29-32.
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.329941
label: catalog number
content: 329941
label: accession number
content: 283729
objectType: label: Object Name
content: Resistance Box
label: Object Name
content: submarine telegraph component
label: Other Terms
content: Resistance Box; Resistance
physicalDescription: label: Measurements
content: overall: 5 1/2 in x 6 7/8 in; 13.97 cm x 17.4625 cm