Telegraph Key
date: label: date made
content: 1873
name: label: maker
content: Wessmann, Martin F.
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 Martin Wessmann's design for an automatic key. His idea involved a key for each letter, number and character, somewhat like a piano keyboard. Each key included a circuit breaker controlled by gearing so that the pulses were generated at a regular speed. That prevented operators from blurring the message.
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.308872
label: catalog number
content: 308872
label: accession number
content: 89797
label: patent number
content: 142826
objectType: label: Object Name
content: telegraph key
label: Object Type
content: Patent Model
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: gutta percha (overall material)
label: Measurements
content: overall: 4 3/4 in x 3 1/4 in x 9 1/2 in; 12.065 cm x 8.255 cm x 24.13 cm