Who Invented the Light Bulb?
Most people think that Thomas Edison invented the light bulb, but they would be wrong. In 1875, Thomas Edison purchased half of a patent. The patent was owned by a Toronto medical electrician. Edison wanted this to further his own research. The researcher who invented the light bulb was James Woodward. Woodward and a colleague by the name of Mathew Evans, filed a patent for the: Woodward and Evan’s Light on July 24, 1874. Evans was described in the patent as a “Gentleman”, but he was a hotel keeper. So this is the story of who invented the light bulb.
Working at Morrison’s Brass Foundry on Adelaide Street in Toronto, they built the first lamp with a shaped rod of carbon. The rod was held between electrodes in a glass bulb filled with nitrogen.
Woodward and Evans were treated as quakes and subjected 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.
In 1876, Woodward obtained a U.S. patent on his electric lamp. In 1879 Thomas Edison considered it important enough 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, and the assumption that Thomas Edison invented the light bulb. This is part of the text from James Woodward’s 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 rotating a magneto Electric Machine, and at Such Velocity, as shall create electricity, enough 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 here before 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 way. 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 rarefied gas that will not unite chemically with the carbon when hot. Electricity is now supplied and in sufficient quantity, to heat the carbon within the vessel to a State of incandescence, the rarefied gas previously introduced now becomes luminous, and makes up the light here 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 1860’s.
In 1880, Swan and Edison teamed up to produce the first “practical” light bulb.
As the reader points out, Edison always claimed, “If I didn’t develop the incandescent light bulb, then I didn’t develop anything.” For the record, this is the chronology of light bulb development as listed in http://inventors.about.com/library/inventors/bllight2.htm:
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 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 below) 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 a 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 on this article Who Invented the Light Bulb, Jennifer. – BR