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: This appears to be a more elaborate unit than that illustrated in Cameron's book. Two Apex boxes are listed on the inventory list among other items as #23.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 wooden case (hinged cover missing) with a hard rubber plate on which is set three binding posts, three connecting blocks (six connectors included) and a sweep switch with 41 contacts. Posts are labeled: "Cable", "Apex", and "A.L." [Artificial Line]; outer ring of contacts are numbered 0 to 40. Marked on plate: "Muirhead & Co. No. 44594". Reference: Duncan H. Cameron, Submarine Telegraphy, International Textbook Company, 1927, pages 29-32. Note, this unit does not look like the illustration in Cameron's book (figure 24; see cat# 329941). It appears to be a more elaborate unit.
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.329940
label: catalog number
content: 329940
label: accession number
content: 283729
objectType: label: Object Name
content: Test Box
label: Object Name
content: submarine telegraph component
label: Other Terms
content: Test Box; Telegraphy
physicalDescription: label: Measurements
content: overall: 5 in x 11 in x 6 in; 12.7 cm x 27.94 cm x 15.24 cm