Model of Bell's Harmonic Telegraph Transmitter
notes: label: Description (Brief)
content: Model of Bell's Harmonic Telegraph Transmitter, L-shaped electro-magnet, mounted on wooden base. Flattened piece of steel clock-spring clamped by one end to one pole of the magnet, while the other end of spring is free to vibrate over the other pole of the magnet. There is also make and break point, adjusted by turning thumb screw. It was while experimenting with an instrument such as this connected with Bell's harmonic telegraph receiver, similar to catalog # 308212, that the first idea of the telephone was evolved. For details see last paragraph, page 13, "Birth and Babyhood of the Telephone", by Thomas A Watson.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from American Telephone & Telegraph Company
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.308211
label: catalog number
content: 308211
label: accession number
content: 70856
objectType: label: Object Name
content: Telegraph Set
label: Object Name
content: harmonic telegraph
label: Other Terms
content: Telegraph Set; Telegraphy; Transmitter
physicalDescription: label: Measurements
content: overall: 3 1/4 in x 3 in x 5 in; 8.255 cm x 7.62 cm x 12.7 cm