Think back. Who invented the light bulb? Thomas Edison? Right? WRONG! In 1875, Edison purchased half of a Toronto medical electricians patent to further his own research. That researcher was named James Woodward. Woodward and a colleague by the name of Mathew Evans, described in the patent as a Gentleman but in reality a hotel keeper, filed a patent for the Woodward and Evans Light on July 24, 1874. Working at the Morrisons Brass Foundry on Adelaide St. West in Toronto, they built the first lamp with a shaped rod of carbon held between electrodes in an glass bulb filled with nitrogen. Woodward and Evans were treated as cranks and subject to much public ridicule. Who needs a glowing piece of metal!! They attempted, with very little success, to form a company to raise money to refine and market their invention. (Where is the federal government when you really need them?) In 1876, Woodward obtained a U.S. patent on his electric lamp and, in 1879, Edison considered it sufficiently important to completely buy out the patent from Woodward, Evans, and all their Canadian partners, similar to what we would do today to avoid equipment leasing issues. Woodward sold a share of his Canadian patent to Thomas Edison in 1885. Thus the electric light bulb became American. In part this is the text of Woodwards original patent: Be it known that We, Henry Woodward of the city of Toronto in the County of York, in the Province of Ontario Medical Electrician, and Mathew Evans also of the city of Toronto, in the County of York, in the Province of Ontario Gentleman, have jointly invented: New and useful improvements in the art or process of obtaining Artificial light by means of Electricity and we do hereby declare that the following is a full clear and exact description of the same. In the first place we use a gas engine, or other suitable motive power, for the purpose of rotating a magneto Electric Machine, and at Such Velocity, as shall create electricity, sufficient to heat certain pieces of Carbon to a state of incandescence. In the Second place, we use pure Carbon and place the same in lamps, or outer suitable vessels, as hereinafter described. A piece of Carbon, as hereinbefore mentioned, pure in quality, and of suitable size, proportionate to the size of lamp or vessel to be used, is scraped and shaped until fitted for the purpose. One electrode is then Connected with the Carbon at the top, and the other electrode is connected with the Carbon at the bottom, in the following manner. A small hole is drilled a short distance into each end of the Carbon to fit the electrodes, and when necessary they are further secured by surrounding them with a portion of plaster of Paris or other suitable substance. The electrodes not passing through the carbons, nor Connecting with each other. It is then enclosed in a globe, or other vessel, either of glass or other Suitable material. The air is then extracted from the said globe, or vessel, after it has been hermetically sealed at the ends, and then filled with rarified gas that will not unite chemically with the carbon when hot. Electricity is now supplied and in sufficient quantity, so as to heat the carbon within the vessel to a State of incandescence, the rarified gas previously introduced now becomes luminous, and constitutes the light herein designated as Woodward and Evans Electric Light. This process will give a light of any required intensity, and there is practically no limit to the number of lights that may be obtained from one Magneto Electric Machine. Special Note: An eagle eyed reader from the UK spotted an error in this original story. I originally stated that Edison was granted a patent in 1876. In fact he was not granted a patent because his invention too closely resembled an invention in the UK of a filament in a vacuum tube, developed by Joseph Swan in the 1860s. In 1880, Swan and Edison teamed up to produce the first practical light bulb. As the reader points out, Edison always claimed, If I didnt develop the incandescent light bulb, then I didnt develop anything. For the record, this is the chronology of light bulb development as listed in : 1809 - Humphry Davy, an English chemist, invented the first electric light. Davy connected two wires to a battery and attached a charcoal strip between the other ends of the wires. The charged carbon glowed making the first arc lamp. 1820 - Warren De la Rue enclosed a platinum coil in an evacuated tube and passed an electric current through it. His lamp design was worked but the cost of the precious metal platinum made this an impossible invention for wide-spread use. 1835 - James Bowman Lindsay demonstrated constant electric lighting system using a prototype light bulb. 1850 - Edward Shepard invented an electrical incandescent arc lamp using a charcoal filament. Joseph Wilson Swan started working with carbonized paper filaments the same year. 1854 - Henricg Globel, a German watchmaker, invented the first true light bulb. He used a carbonized bamboo filament placed inside a glass bulb. Mathew Evans patented a light bulb. 1878 - Sir Joseph Wilson Swan (1828-1914), an English physicist, was the first person to invent a practical and longer-lasting electric light bulb (13.5 hours). Swan (pictured at right) used a carbon fiber filament derived from cotton. 1879 - Thomas Alva Edison invented a carbon filament that burned for forty hours. Edison placed his filament in an oxygenless bulb. (Edison evolved his designs for the light bulb based on the 1875 patent he purchased from inventors, Henry Woodward and Matthew Evans.) 1880 - Edison continued to improved his light bulb until it could last for over 1200 hours using a bamboo-derived filament. Thanks for keeping me honest, Jennifer. -
Posted on: Sat, 19 Oct 2013 09:08:14 +0000