working in New York City to install the electric light system,
Edison returned to New Jersey in 1887. He opened a new, larger
laboratory in West Orange. More than 500 of Edison's patents
came out of this lab.
Edison's most famous invention from his "Invention Factory"
is the first movie viewer
and movie camera, which he developed with William Kennedy
Around this time, Edison returned to some of his earlier inventions
to improve them. He "perfected" the phonograph in 1888, and
in 1896, he began marketing a home phonograph. In the early
1900s, he worked on batteries, X-rays, and the first talking
As the nation became involved in World War I, the U.S. military
turned to Edison for help and advice. He was named head of
the Naval Consulting Board, working primarily in submarine
Edison continued working at the Invention Factory through
the 1920s. Although his health had begun to worsen, he was
able to participate in a re-enactment of the invention of
his incandescent light bulb in Dearborn, Michigan, in 1929.
(Henry Ford, founder of Ford Motor Company, had reconstructed
Edison's Menlo Park laboratory there.)
Edison died in 1931 at his New Jersey estate, Glenmont. To
honor Edison, people across the nation dimmed their light
bulbs for one minute on the day of his funeral.
Although Edison's laboratory closed after his death, the National
Park Service preserved the West
Orange laboratory as a national historic site. It is currently
closed for renovations but is scheduled to reopen in 2005.