In a telephone, speech is changed into
electrical impulses by means of a microphone. The 'Electric
Speaking Telephone' was invented by Alexander Graham Bell in 1876.
The microphone and receiver were identical and consisted of a
magnet surrounded by a solenoid placed close to an iron membrane.
The first words Bell spoke on his telephone to his assistant; "Mr
Watson, come here, I want you!" Just two hours after Bell had
patented his telephone, Elisha Gray filed a patent for a slightly
different telephone. Grey tried to sue Bell but the United States courts declared
that Bell was the inventor of the telephone. It has since been
proven that Bells original patent would not have worked while
Grays design would have. Development,
improvement and use of the telephone was rapid. The first
commercial telephone exchange opened in New Haven, Connecticut in
the United States in 1878, while a year later the first telephone
system in London was opened.
Due to telephone exchanges requiring great
manpower to switch the lines through several attempts were made to
produce an automatic system. The first successful automatic system
was invented by Almon Strowger, who was an undertaker from Kansas
City, in 1889. He decided to invent the system as the competing
undertaker in the city had a wife working at the local telephone
exchange, he was frustrated by calls placed through to the
competition when they were supposed to go to him. Many country's
still rely on telephone exchanges based on his ideas.