two-way telegraph repeater
Date1900-1920
Inventory Number1997-1-0592
ClassificationTelegraph Relay
Subject
Maker
Western Electric Company
1869 - 1995
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Origin
Dimensions9.3 × 13.6 × 39.4 cm (3 11/16 × 5 3/8 × 15 1/2 in.)
Material
DescriptionDouble telegraph apparatus mounted on a rectangular wooden base, the latter sitting on an additional black metal base. The left side and the right side of the apparatus are almost mirror images of one another. The right side consists of a pair of metal cylinders (an electromagnet) connected in the back by a black metal plate. A brass coil runs from the back of the plate to a brass knob with an adjustment dial on the end. A movable brass bar with a black handle on the end sits below the knob and dial. Fastened to the base in the middle, the bar is able to pivot over four metal circles on the base.
A u-shaped brass rod sits on a piece of brass lodged between the cylinders, extending toward the front of the magnet. In the center of the u-shape is a narrow piece of metal attached to a thin plate sitting in front of the cylinders. A spring extends from the thin plate to a brass post with a dial on top. There are four binding posts in the right corner of the base along the top edge, and a brass knob extending horizontally off the right side of the base.
The left side of the apparatus differs from the mirror image of the right only in that there is no spring and there is a double adjustment knob on either side of the u-shaped bar.
A blue triangle is painted in the top-right corner of the base, telling us that it was used in the department of physics at Harvard as a didactic instrument.
A u-shaped brass rod sits on a piece of brass lodged between the cylinders, extending toward the front of the magnet. In the center of the u-shape is a narrow piece of metal attached to a thin plate sitting in front of the cylinders. A spring extends from the thin plate to a brass post with a dial on top. There are four binding posts in the right corner of the base along the top edge, and a brass knob extending horizontally off the right side of the base.
The left side of the apparatus differs from the mirror image of the right only in that there is no spring and there is a double adjustment knob on either side of the u-shaped bar.
A blue triangle is painted in the top-right corner of the base, telling us that it was used in the department of physics at Harvard as a didactic instrument.
Signedon plaque on base: WESTERN ELECTRIC COMPANY
Inscribedon base, top-center: PNT. APPL'D FOR
beside each movable bar: CUT
FunctionThe telegraph repeater was used to faciliate the sending of messages over long distances.
According to George B. Prescott's History, Theory and Practice of the Electric Telegraph, available here:
"The repeater is an apparatus for the purpose of duplicating from one electric circuit to another the breaks and completions received from the transmitting station, for the purpose of renewing the power lost by the escape of the electric fluid into the earth through imperfect insulation."
According to George B. Prescott's History, Theory and Practice of the Electric Telegraph, available here:
"The repeater is an apparatus for the purpose of duplicating from one electric circuit to another the breaks and completions received from the transmitting station, for the purpose of renewing the power lost by the escape of the electric fluid into the earth through imperfect insulation."
ProvenanceFrom the Department of Physics, Harvard University.
U.S. Electrical Supplies
Date: 1910-1920
Object number: 1997-1-0578
