Thomas Edison

Thomas Alva Edison

was born 1847, the last of 7 children, educated at home
At 16 got a job as a telegrapher--wandered around for five years taking jobs in different areas and playing with the machines
In 1868 he gave up his job and set out to be an inventor
first patent--vote recording machine--did not sell. Lesson--demand

vote recording machine, Henry Ford Museum, PEM photo

moved from Boston to NY and got a job on Wall Street. Improved stock ticker (1869) and worked on duplex and quadraplex telegraphs (multiple messages on one wire)
By age 29 he was successful enough to set up a shop solely devoted to invention.
improved Alexander Graham Bell's telephone (Bell and Elisha Gray invented the same thing but Bell saw the potential, while Gray, a professional telegraph inventor, did not)
Edison's next invention was the phonograph in 1878 ( more information , samples )--not a big money-maker but gave him a reputation as a wizard that helped him raise venture capital.
Meanwhile he was setting up an invention system, hiring mechanics, mathematicians, and eager young inventors. He called his new shop in Menlo Park, New Jersey an "invention factory" and promised a "minor invention every ten days and a big thing every six months or so." ( Edison's patent production , list of patents , The patent system in Edison's time ) In some ways this lab was a precursor of the industrial research laboratory, except it was an independent invention lab, not part of a large corporation. Thomas Edison quotes

Thomas Edison

Finally he decided that the big problem to solve was electric light--made a big announcement in 1878

Edison's first lightbulb

Gas utility developed in first half of the 19th century was meeting the need for household light--Edison explicitly set out to compete.
The arc light was in use for public places, streetlighting, and search lights, after the invention of a practical dynamo about 1870, but was not practical for the home. Edison saw the challenge was to subdivide the light. It was known that incandescent light was a potential solution, but no one had been able to make it work (the filament either melted or burned up)
scientists said that connecting light bulbs in parallel was impossible
Edison realized he needed all the parts of the system--improved vacuum pump, efficient dynamo, wiring systems (and the practicalities of that meant that the filament had to have high resistance), meters .
The hardest problem to solve was the filament--at first Edison thought he could regulate current to a platinum filament so it wouldn't melt. Edison announced he was close to success--stock prices for gas light companies fell. Edison organized the Edison Electric Light Company, backed by investors such as J. P. Morgan and the Vanderbilts. But the platinum filament approach didn't work, despite struggles to find a solution through the middle of 1879.
Edison had to resort to hiring a Princeton-trained physicist ( Francis Upton ) to help him and eventually (Oct. 1879) to trial and error of over two thousand materials. Finally found a new approach that worked better--carbon instead of platinum. Edison's patent
On New Years Eve 1879 he put on a big display for press and backers-- got lots of publicity .
in 1882 he completed the first commercial system--Pearl Street Station ( consequences )

Generators at Pearl Street Station

Competition popped up very quickly

Thompson-Houston arc light company and George Westinghouse , who had invented the railway air brake in 1869.
Westinghouse realized that high voltage would transmit further and that if you used alternating current you could transform it down again for safety.
Edison fought bitterly against the AC approach --for one thing he didn't have the necessary mathematics.
Thompson-Houston went to AC and was able to take control of Edison's company in 1892--became GE

electric chair story :

Edison argued that AC was too dangerous and arranged public demonstrations where stray cats and dogs (purchased from local schoolboys for 25 cents each) were electrocuted. He even executed an elephant (video)
A lot of publicity was carried out not by Edison but by a man named Harold Brown, who had the support of Edison and the technical help of some of Edison's associates.
In 1888 New York state changed the death penalty from hanging (which sometimes didn't work well) to electrocution, and Edison and his associates lobbyied for the selection of an alternating current design.
Westinghouse funded appeals by some prisoners who argued that electrocution was cruel and unusual punishment.
In 1890 Auburn State Prison used the first electric chair to execute a convicted murderer, using Westinghouse alternators.
"Kemmler was strapped into the chair on August 6, 1890. The first jolt of alternating current lasted 17 seconds. Kemmler continued struggling. A second jolt lasted more than a minute, until smoke was seen rising from the body. It was, The New York Times said, 'an awful spectacle, far worse than hanging.' The state commissioner on humane executions saw it differently. It was, he said, 'the grandest success of the age.' " source , more information on the history of the electric chair , another story

Artist's rendering of Kemmler's execution

Edison went on to work on motion pictures, an ore separator , synthetic rubber, and concrete houses .
Edison's special talents:

PEM photo, Henry Ford Museum

he was an inventor-entrepreneur--good at business
he thought out the whole system rather than just inventing one gadget
he was good at finding something useful to do with the results of a failed experiment (1093 patents)
he also had a particular talent for publicity

this page written and copyright Pamela E. Mack
History 122
last updated 10/24/05