Electricity pioneer Lewis Latimer drew this component of an arc lamp, an early type of electric light, for the U.S. Electric Lighting Company in 1880.
The son of escaped slaves and a Civil War veteran at age sixteen, Latimer trained himself as a draftsman. His technical and artistic skills earned him jobs with Alexander Graham Bell and Thomas Edison, among others. An inventor in his own right, Latimer received numerous patents and was a renowned industry expert on incandescent lighting.
Keyed socket for a Mather incandescent lamp, c. 1885. Brass shell with brass key, threaded post connector. Ten brass leaf-springs are spaced around the top of the removable shell to hold a Mather lamp. No extant maker's marks.
Sepia photo of a Beardslee telephone device used in patent litigation. Image taken at unknown photo studio: "109 8th Ave., NYC." Written on back: "Magneto telephone made by George W. Beardslee at College Point, Long Island, NY 1865 / Testimony by George W. Beardslee in the case of the Molecular Telephone Co., of NY / "Exhibit Beardslee Holcomb / Telephone" / J A W Special Examiner / NY Dec 4th 1884 / No 1 _ instrument as used complete". And "copied Apr 1947 / neg no 37 686". Stamped "Section of Transportation / and Engineering".
Telegraph relays amplified electrical signals in a telegraph line. Telegraph messages traveled as a series of electrical pulses through a wire from a transmitter to a receiver. Short pulses made a dot, slightly longer pulses a dash. The pulses faded in strength as they traveled through the wire, to the point where the incoming signal was too weak to directly operate a receiving sounder or register. A relay detected a weak signal and used a battery to strengthen the signal so that the receiver would operate.
“Main line” relays like this Western Electric unit were one of the most common types of relay and, as seen in this piece, were typically made with a resistance of 150 ohms. As the name suggests, main line relays served on major intercity circuits several hundred miles long. Better known for their Bell System telephone equipment, Western Electric manufactured a wide range of electrical devices.
Weston US-based keyed socket, c 1885. Brass shell, threaded post connector with set-screw, plastic key. Shell top and bottom held together with 3 screws. No extant maker's marks.