For sale is an extremely rare letter penned by Thomas Alva Edison with references to parts of the light bulb. The letter is written by Edison from New York to his partner Francis Robbins Upton located in East Newark, NJ. The letter is written as follows. Please make up a small sample box of fibres, filiments and carbons and forward to C. Hoskins Milwaukee Wis and oblige. Put in a ½ c. Also included is the envelope penned by Edison and written as follows. Francis R Upton Esq. Francis Robbins Upton was an American mathematician and physicist who, as assistant to Thomas Edison, contributed to the development of the American electric industry. Upton studied at Bowdoin College, Brunswick, Maine; Princeton University; andwith Hermann von HelmholtzBerlin University. In 1878 he joined Edison at his laboratory in Menlo Park, N. There he worked out mathematical problems arising during the development of such devices as the incandescent lamp, the watt-hour meter, and large dynamos. He was a partner and general manager of the Edison Lamp Works, established in 1880. In 1878, Thomas Edison began serious research into developing a practical incandescent lamp and on October 14, 1878, Edison filed his first patent application for “Improvement In Electric Lights”. However, he continued to test several types of material for metal filaments to improve upon his original design and by Nov 4, 1879, he filed another U. Patent for an electric lamp using a carbon filament or strip coiled and connected… To platina contact wires. Although the patent described several ways of creating the carbon filament including using “cotton and linen thread, wood splints, papers coiled in various ways, ” it was not until several months after the patent was granted that Edison and his team discovered that a carbonized bamboo filament could last over 1200 hours. This discovery marked the beginning of commerically manufactured light bulbs and in 1880, Thomas Edisons company, Edison Electric Light Company begain marketing its new product. Both the letter and envelope have been preserved and matted since 1976. Included with the letter is a certificate of authenticity by James Spence Authentication (JSA). Please reach out with any questions. The item “Thomas Edison Signed Letter with Light Bulb Content JSA” is in sale since Tuesday, January 14, 2020. This item is in the category “Collectibles\Historical Memorabilia\Inventors & Geniuses”. The seller is “oldemast” and is located in Duluth, Minnesota. This item can be shipped to United States.
- Year: 1885