Phelps distance transmitter
Date: circa 1881
Inventory Number: 8024b
Classification: Telephone
Subject:
Maker: George Phelps (1820 - 1888)
Owner: Jefferson Physical Laboratory, Harvard University (founded 1884)
Cultural Region:
Place of Origin:
Dimensions:
10 × 12.3 × 15.6 cm (3 15/16 × 4 13/16 × 6 1/8 in.)
Description:
A distance transmitter, made by prolific Western Union engineer and inventor George Phelps of Brooklyn, New York. Device is housed in a rectangular wooden case with a beveled top edge. The cover has brass hinges that secure it to a flat wooden base and a brass latch. The base sits atop a rectangular funnel-shaped wooden horn.
Inside the case, a circular diaphragm, horizontally-oriented, in a brass frame is inset into the flat wooden base. A brass post supporting a short cylindrical disk sits in the center of the diaphragm, and is connected by two wire leads to horizontal wooden spool of coiled wire supported by a wooden bracket mounted at the edge of the frame.
The entire assembly has two pairs of brass binding posts, with slot-headed screws, mounted along the back edge of the case, on either side of a brass bracket for wall mounting.
Device is signed on brass plate on front of case, "G. M. PHELPS / Brooklyn, N.Y."
Inside the case, a circular diaphragm, horizontally-oriented, in a brass frame is inset into the flat wooden base. A brass post supporting a short cylindrical disk sits in the center of the diaphragm, and is connected by two wire leads to horizontal wooden spool of coiled wire supported by a wooden bracket mounted at the edge of the frame.
The entire assembly has two pairs of brass binding posts, with slot-headed screws, mounted along the back edge of the case, on either side of a brass bracket for wall mounting.
Device is signed on brass plate on front of case, "G. M. PHELPS / Brooklyn, N.Y."
Signedsigned on brass plate: G. M. PHELPS / Brooklyn, N.Y.
Inscribedsigned on brass plate: G. M. PHELPS / Brooklyn, N.Y.
FunctionConversion of sound into electrical impulses for transmission over a distance
Curatorial RemarksOld tag: "Phelps [sic] microphone Transmitter Original 8024b"
ProvenanceJefferson Laboratory, Physics Department, Harvard University
Published ReferencesThis instrument is described in:
Thomas G. Hedberg, "Catalogue: Telephones, Phonographs and Related Instruments in The Collection of Historical Scientific Instruments at Harvard University." William Andrewes, Project Director (unpublished manuscript, President and Fellows of Harvard College and Thomas G. Hedberg, 1989. Fifth Draft), p. 71.
