Information Technology Reference
In-Depth Information
States. New York City alone had 600 fire alarm telegraphs. When a person pulled the
lever of the alarm box, it automatically transmitted a message identifying its location to
a fire station. These devices greatly improved the ability of fire departments to dispatch
equipment quickly to the correct location [27].
Alexander Graham Bell was born in Edinburgh, Scotland, into a family focused on
impairments of speech and hearing. His father and grandfather were experts in elocution
and the correction of speech. His mother was almost completely deaf. Bell was educated
to follow in the same career path as his father and grandfather, and he became a teacher
of deaf students. Later, he married a deaf woman.
Bell pursued inventing as a means of achieving financial independence. At first he
focused on making improvements to the telegraph. A significant problem with early
telegraph systems was that a single wire could transmit only one message at a time. If
multiple messages could be sent simultaneously along the same wire, communication
delays would be reduced, and the value of the entire system would increase.
Bell's solution to this problem was called a harmonic or musical telegraph. If you
imagine hearing Morse code, it's obvious that all of the dots and dashes are the same
note played for a shorter or longer period of time. The harmonic telegraph assigned
a different note (different sound frequency) to each message. At the receiving end,
different receivers could be tuned to respond to different notes, as you can tune your
radio to hear only what is broadcast by a particular station.
Bell knew that the human voice is made up of sounds at many different frequencies.
From his work on the harmonic telegraph, he speculated that it should be possible to
capture and transmit human voice over a wire. He and Thomas A. Watson succeeded
in transmitting speech electronically in 1876. Soon after, they commercialized their
invention.
Nearly all early telephones were installed in businesses. Leasing a telephone was
expensive, and most people focused on its commercial value rather than its social value.
However, the number of phones placed in homes increased rapidly in the 1890s, after
Bell's first patent expired.
Once telephones were placed in the home, the traditional boundaries between pri-
vate family life and public business life became blurred. People enjoyed being able to
conduct business transactions from the privacy of their home, but they also found that
a ringing telephone could be an unwelcome interruption [28].
Another consequence of the telephone was that it eroded traditional social hierar-
chies. An 1897 issue of
Western Electrician
reports that Governor Chauncey Depew of
New York was receiving unwanted phone calls from ordinary citizens: “Every time they
see anything about him in the newspapers, they call and tell him what a 'fine letter he
wrote' or 'what a lovely speech he made,' or ask if this or that report is true; and all this
from people who, if they came to his office, would probably never say more than 'Good
morning' ” [29].
