HISTORY OF TELEPHONE3
Early Telephone Development3
The Beginning (1876-1900)4
The New Century (1901-1940)6
Modern Time (1940-Today)6
A few centuries ago, there were only a few kinds of communication that people can use. They could speak to each other, they can use smoke as a means of communication to send their message from one place to another or they could use mail. Later on, they also had telegram. During the modern age, telephone is one of the most important inventions in the field of communications. It is a disruptive technology that had made other means of communication become obsolete. Nowadays, it has played an irreplaceable role in our daily life but not many people know about the origin and history of telephone. This assignment is to briefly introduce to you the history of telephone. It has a long history so I broke it into 4 periods: Early Telephone Development, The Beginning (1876-1900), The New Century (1904-1940) and Modern Time (1940-Today)
HISTORY OF TELEPHONE
Early Telephone Development
In 1729, An English chemist named Stephen Gray had successfully transmitted electricity over a wire. In 1746, Dutchman Pieter van Musschenbroek and German Ewald Georg von Kleist independently developed the Leyden jar which was named after its Holland city of invention. It is a device that was used by early experimenters to help build and store electricity. It was also called a "condenser" because many people considered electricity as fluid or matter that could be condensed. Over the years these jars were used in countless experiments, lectures, and demonstrations Figure 1: A basic anatomy of a Leyden jar
In 1820, a Danish physicist Christian Oersted discovered electromagnetism, the critical idea needed to develop electrical power and to communicate. Oersted discovered that an electric current creates a magnetic field but he didn’t know if a magnetic field could create electricity or not. If so, a new source of power would be born and the principle of electromagnetism, if fully understood and applied, would open a promise new era of communication Figure 2: Christian Oersted In 1830 the great American scientist Professor Joseph Henry transmitted the first practical electrical signal. Henry had showed that electromagnetism could do more than create current or pick up heavy weights - it could communicate. In a demonstration in his Albany Academy classroom, Henry created the forerunner of the telegraph. Because Henry did not pursue electrical signaling, he did help someone who did. And that man was Samuel Finley Breese Morse.
In 1837, Samuel Morse invented the first workable telegraph. Joseph Henry helped Morse build a telegraph relay or repeater that allowed long distance operation. The telegraph later helped unite the country and eventually the world. As shown in Figure 8 below, his system used 2 keys to make or break the electrical circuit, a battery to produce power, a line joining sending telegraph station to receiving station and 2 electromagnetic receivers or sounders that being turned on and off to produce a clicking noise. He completed the package by devising the Morse code system of dots and dashes. A quick key tap broke the circuit momentarily, transmitting a short pulse to a distant sounder, interpreted by an operator as a dot. A more lengthy break produced a dash.
Figure 5&6: Samuel Morse and a diagram on how telegraph works In 1861, A German physicist and school teacher Johann Phillip Reis produced the first non-working telephone. His transmitter and receiver used a cork, a knitting needle, a sausage skin, and a piece of platinum to transmit bits of music and certain other sounds. But intelligible speech could not be reproduced.
Figure 7&8: Johann Phillip Reis and his telephone instrument