Telegraph Key
date: label: date made
content: 1881
name: label: maker
content: L. G. Tillotson & Co.
notes: label: Description (Brief)
content: Telegraph keys are electrical on-off switches used to send messages in Morse code. The message travels as a series of electrical pulses through a wire. The operator pushes the key’s lever down briefly to make a short signal, a dot, or holds the lever down for a moment to make a slightly longer signal, a dash. The sequence of dots and dashes represent letters and numbers. This key has a switch on the side called a circuit-closer that takes the key off-line when not in use.
label: Description (Brief)
content: This key shows a special set of contact wheels that are designed to prevent sticking of the contacts due to dirt or corrosion. The technique was disclosed in two 1882 US patents: 256645 issued to George Cummings, and 256646 issued to Cummings and Clara Brinkerhoff.
label: Location
content: Currently on loan
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Telegraph Keys
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content: Communications
creditLine: label: Credit Line
content: from Pennsylvania Railroad Company
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.221144
label: catalog number
content: 221144
label: accession number
content: 41460
objectType: label: Object Name
content: telegraph key
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: rubber (overall material)
label: Physical Description
content: brass (overall material)
label: Measurements
content: overall on base: 2 3/4 in x 3 in x 6 in; 6.985 cm x 7.62 cm x 15.24 cm