Invention of the telephone

The invention of the telephone was the culmination of work done by many individuals, and involved an array of lawsuits founded upon the patent claims of several individuals and numerous companies.

The concept of the telephone dates back to the string telephone or "lover's telephone" that has been known for centuries, comprising two diaphragms connected by a taut string or wire. Sound waves are carried as mechanical vibrations along the string or wire from one diaphragm to the other. The classic example is the tin can telephone, a children's toy made by connecting the two ends of a string to the bottoms of two metal cans, paper cups or similar items. The essential idea of this toy was that a diaphragm can collect voice sounds from the air, as in the ear, and a string or wire can transmit such collected voice sounds for reproduction at a distance. One precursor to the development of the electromagnetic telephone originated in 1833 when Carl Friedrich Gauss and Wilhelm Eduard Weber invented an electromagnetic device for the transmission of telegraphic signals in Göttingen in Lower Saxony, helping to create the fundamental basis for the technology that was later used in similar telecommunication devices. Gauss's and Weber's invention is purported to be the world's first electromagnetic telegraph.

In 1840, American Charles Grafton Page passed an electric current through a coil of wire placed between the poles of a horseshoe magnet. He observed that connecting and disconnecting the current caused a ringing sound in the magnet. He called this effect "galvanic music".

Innocenzo Manzetti considered the idea of a telephone as early as 1844, and may have made one in 1864, as an enhancement to an automaton built by him in 1849.

Charles Bourseul was a French telegraph engineer who proposed (but did not build) the first design of a make-and-break telephone in 1854. That is about the same time that Meucci later claimed to have created his first attempt at the telephone in Italy.

Bourseul explained: "Suppose that a man speaks near a movable disc sufficiently flexible to lose none of the vibrations of the voice; that this disc alternately makes and breaks the currents from a battery: you may have at a distance another disc which will simultaneously execute the same vibrations.... It is certain that, in a more or less distant future, speech will be transmitted by electricity. I have made experiments in this direction; they are delicate and demand time and patience, but the approximations obtained promise a favourable result."

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