Telegraph Key Patent Model
date: label: date made
content: 1875
name: label: maker
content: Crandall, Lucien S.
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 sequence and duration of pulses represent letters and numbers. This patent model shows Lucien Crandall's design for an automatic key. His idea involved a key for each letter, number and character, set on a frame like a typewriter. Each key included a ratcheted wheel with conducting and insulated segments around the edge. When the operator pressed a key, the wheel rotated and generated morse code pulses at a regular speed. His goal was to permit operators to send messages, "with greater rapidity, uniformity, and certainty than with the common telegraphic key."
label: Description (Brief)
content: Note: the US Patent Office tag for this model misspells the inventor's name: Randall instead of Crandall.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Telegraph Keys
label: See more items in
content: Communications
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.308883
label: catalog number
content: 308883
label: accession number
content: 89797
label: patent number
content: 168144
objectType: label: Object Name
content: telegraph key
label: Object Type
content: Patent Model
label: Other Terms
content: telegraph key; Telegraphy
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: metal (overall material)
label: Physical Description
content: gutta percha (overall material)
label: Measurements
content: overall: 6 in x 2 1/2 in x 1 in; 15.24 cm x 6.35 cm x 2.54 cm