Summary
In December 1875 Western Union wrapped up the quadruplex court
battles and gave Edison a new contract. This contract spelled out
their expectations for Edison's patents in clear language and gave
him the assignment of developing an acoustic telegraph. He used
the money to build a research laboratory in Menlo Park, New Jersey,
twenty-five miles southwest of New York City. Menlo Park was where
Edison built the phonograph, the electric light bulb, and tinkered
with Alexander Graham Bell's telephone technology. About thirty
men worked in the two-story facility, and while Edison reinforced
his reputation as an exacting boss, the whole group became very
close.
Edison's life was changing in other ways as well. His
new family also moved to Menlo Park when the facility was opened.
On December 25, 1871, he married a young girl named Mary Stilwell. She
was a sixteen-year-old girl from a modest Newark family, very quiet
and retiring. By 1878 they had three children: Marion, Thomas Jr.,
and William. It was not an easy marriage for her. Because Edison
was often at the Menlo Park laboratory, where experimental work
often pressed him to remain for days at a time, Mary Stilwell was
forced to run the house and take care of the children by herself most
of the time.
Edison's invention of the phonograph grew out of his experiments
with telephone technology. The telephone was a new invention with
a reputation as a novelty toy. In 1876, it was the subject of a
patent dispute by two men: Alexander Graham Bell, a teacher of the
hearing-impaired in Boston, and Elisha Gray, a Chicago electrician.
Although Gray had invented the basic technology in 1874, he did
not believe the device was marketable. After Bell demonstrated his
own invention at the Philadelphia Centennial Exposition in 1876
and filed a patent for it, Gray changed his mind, and the telephone
became the subject of a court battle.
In the end, Bell triumphed over the courts but faced market
competition from Edison. When Bell began using the telephone to
compete with the telegraph in urban areas, Western Union bought Gray's
telephone patent and put Edison to work on improving Bell's device.
Edison discovered the weakness of Bell's device–poor sound transmission–and
invented a transmitter that greatly improved the volume of the
telephone. Western Union gained a tremendous advantage by using
Edison's transmitter with Gray's telephone receiver, which infuriated
Bell. He saw his chance to respond when Edison's transmitter was
tested in England in November 1878. They had tested Edison's device
by linking it to a Bell receiver. Bell threatened to sue Edison
for patent infringement.
Edison tried to create his own receiver to avoid a court
battle, but his attempts were inferior to Bell's. In addition,
the British government ruled against Edison in 1880, in the court
decision The Attorney General v. The Edison Telephone Company
of London. Western Union worked out a deal with Bell
that gave him control over Edison's transmitter patent in return
for exclusive control over long-distance messages sent through
telephone exchanges.
Though he lost the battle over the telephone, Edison's
experiments in this area led him to a new discovery: the phonograph.
In November 1877, while testing a variety of telephone sound diaphragms,
Edison stumbled upon the idea of using the diaphragm to play back
sound. With some of his staff, he set up the diaphragm on an automatic
telegraph stand and poked a small hole in it. They ran small pieces
of paper underneath it and spoke. To their excitement, crude sounds
were played back when they ran the paper through a second time.
