|Think back. Who invented the light bulb?
Thomas Edison? Right?
In 1875, Edison purchased half of a Toronto medical electrician's
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 Evan's Light on July 24, 1874.
Working at the Morrison's 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
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 Woodward's original
|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
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'
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.
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 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. - BR
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