Ader "bull ring" receiver
Date: circa 1881
Inventory Number: 8022b
Classification: Telephone
Dimensions:10 × 7.7 × 5.4 cm (3 15/16 × 3 1/16 × 2 1/8 in.)
box: 23.5 × 36.8 × 21.3 cm (9 1/4 × 14 1/2 × 8 3/8 in.)
DescriptionAn Ader telephone receiver, made by Louis-Clément Breguet for the Ader company. The receiver is known as a "bull ring" type, because of its shape. The receiver housing is made of nickel-plated brass and steel and consists of two flat metal disks, stacked to form a short cylinder.
Around the edge of the back cylinder is inscribed, "[star] STE GLE DES TELEPHONES [star]." On the back face is inscribed, "SYSTEME ADER BTE S.G.D.G.; between the magnet poles is inscribed, "BREGUET No 3705."
A hard rubber fluted mouthpiece/earpiece is centered on the outer face of the front cylinder. A piece of the edge of the mouthpiece/earpiece is broken off.
On the opposite side is a ring-shaped magnet which serves as a handle, and a pair of metal binding posts with slotted head screws. The ring shape of the magnet was designed to create a strong magnetic field by bringing both magnet poles near the vibrating diaphragm located under the circular opening on the face of the earpiece, and increase its sensitivity.
A pair of green cloth-covered electrical cords is attached to the binding posts. The cords are joined along most of their length and terminate in two ends, each end finshed with a metal electrical pin plug.
Signedsigned: [star] STE GLE DES TELEPHONES [star]
Inscribedon back: SYSTEME ADER BTE S.G.D.G.;
between magnet poles: BREGUET No 3705
FunctionConversion of electrical signals into sound for output
Historical AttributesOld tag: "With Telephone Collection taken from Jeff 1953"
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 William Andrewes, Project Director (unpublished manuscript, President and Fellows of Harvard College and Thomas G. Hedberg, 1989.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), pp. 64-66.
See also:
William Henry Preece and Julius Maier, The Telephone (London: Whittaker & Co., 1889), pp.50-51.
See also:
George B. Prescott, Bell's Electric Speaking Telephone: Its Invention, Construction, Application, Modification and History. (New York: D. Appleton and Company, 1884). p.376.