Edison carbon button transmitter
Date1878
Inventory Number8051a
ClassificationTelephone
Subject
Maker
Thomas Alva Edison
1847 - 1931
Cultural Region
Place of Origin
Dimensions29.9 × 12.8 × 8.7 cm (11 3/4 × 5 1/16 × 3 7/16 in.)
Material
DescriptionAn Edison carbon button transmitter, consisting of a mouthpiece atop a jointed brass arm, mounted on a four-footed rectangular brass base with curved cutouts.
The arm has two disk-shaped adjustable pivot joints, at the midpoint and at the mouthpiece. The mouthpiece consists of a disk, secured by screws, which supports a flared bowl-shaped mouth piece. A length of electrical cord, covered in green cloth, extends from mouthpiece along the arm to the midpoint.
On top of the base is a pair of brass binding posts with knurled-edge thumb screws.
The transmitter operates by placing a ball of carbon in contact with a steel diaphragm to create variable resistance.
The arm has two disk-shaped adjustable pivot joints, at the midpoint and at the mouthpiece. The mouthpiece consists of a disk, secured by screws, which supports a flared bowl-shaped mouth piece. A length of electrical cord, covered in green cloth, extends from mouthpiece along the arm to the midpoint.
On top of the base is a pair of brass binding posts with knurled-edge thumb screws.
The transmitter operates by placing a ball of carbon in contact with a steel diaphragm to create variable resistance.
Signedunsigned
Curatorial RemarksEdison's Menlo Park laboratory in New Jersey was in an area now known as Edison.
FunctionConversion of sound into electrical signals for transmission over a distance
ProvenanceJefferson Laboratory, Physics Department, Harvard University
Thomas Alva Edison
Date: circa 1878
Accessories: magneto bell (8040b)
Object number: 8040a
Société Générale des Téléphones
Date: 1880
Object number: 8029
Edison Manufacturing Company
Date: circa 1876
Object number: 1997-1-0698
Societé du Telephone Edison
Date: 1879-1880
Object number: 8020
American Speaking Telephone Company
Date: circa 1878
Object number: 8041
Thomas Alva Edison
Date: circa 1878
Accessories: telephone receiver (8040a)
Object number: 8040b
