TELEPHONE. In a broad sense, the term telephone or tele phony includes the entire art of speech transmission with the many accessories and operating methods which research, develop ment, and invention have supplied to facilitate and extend con versation at a distance by electrical means. The telephone was invented in 1876, at Boston, Mass., U.S.A., by Alexander Graham Bell (q.v.). While endeavouring to construct a "harmonic tele graph" with which he hoped to send several telegraphic messages simultaneously over a single wire, Prof. Bell was also trying to transmit speech electrically. On June 2, 1875, he succeeded in transmitting by wire the sound of a twanging clock spring. Further experiments produced on March Io, 1876, an instrument which successfully transmitted a complete sentence, Prof. Bell's sum mons to his assistant in another room : "Mr. Watson, come here, I want you." Bell himself, during his experiments, stated the cor rect principle of telephone transmission as follows : If I could make a current of electricity vary in intensity precisely as the air varies in density during the production of sound, I should be able to transmit speech telegraphically.
Bell was the first to utilize a continuous current, intensified and diminished in proportion to the sound waves projected into the transmitter. Others had predicted the possibility of trans mitting speech by wire but had not hit upon the only practicable method. Charles Bourseul, a Frenchman, published an article as early as 1854 in which he described a method that he believed might be used to transmit speech electrically. An Italian named Antonio Meucci, about 1857 sought some way of transmitting the voice by wire. In 1861 Philipp Reis, a German, produced an in strument constructed along lines similar to those laid down by Bourseul, which would transmit sound of a constant pitch, but proved incapable of transmitting continuous speech. In the United States, several other experimenters were working along lines similar to Bell's at about the same time. Prof. Elisha Gray, in fact filed a caveat (q.v.) on the subject in the United States Patent Office only a few hours after Bell filed his application for a patent on his "improvement in telegraphy," as he described his invention of the telephone. The claims of Prof. Gray and of other American inventors, notably Prof. A. E. Dolbear and Daniel Drawbaugh, were threshed out in prolonged litigation which re sulted in Bell's patent being upheld and his claims to be the in ventor of the telephone being officially established.
apathy in the United States and in Great Britain and other countries was one of the most disheartening diffi culties faced by those who were endeavouring to introduce the tele phone. The development of the telephone business was under taken by a group of Prof. Bell's backers, under the leadership of Thomas Sanders and Gardiner G. Hubbard, whose daughter Bell soon afterwards married. They began renting or lending tele phones in pairs to individuals for local communication. The tele phoning was all done over a single iron wire connecting the two instruments with grounded return circuits. There were no switch boards to afford communication among a number of users, calling devices were extremely crude and transmission was uncertain and poor at best.
In 1878 the first telephone switchboard for commercial service was placed in operation at New Haven, Conn., with twenty-one subscribers. Those interested in introducing the Bell telephone to public use early adopted the permanent policy of leasing tele phones instead of selling them, and granted licenses to authorized agents or licensees for the commercial development of the tele phone business in many parts of the United States. These licensee agencies gradually developed into local exchange systems and ultimately into local operating companies. The owners of the tele phone patent early incorporated their business, and funds were raised for its progressive development, under the leadership of Theodore N. Vail, who became General Manager in 1878. Within ten years after the issuance of the Bell patent the Bell Telephone System had attained an organization approximating its present form. The local systems were gradually brought together into regional' companies operating throughout a state or several states. The telephone systems of these regional companies were linked together by long distance circuits operated by the American Tele phone and Telegraph Company. This company was originally formed to build and operate the long lines as a subsidiary of the American Bell Telephone Company, which had become the parent company of the Bell System by acquiring the ownership of the Bell patents and purchasing stock in the regional telephone companies. Later the American Telephone and Telegraph Com pany exchanged its stock for that of the American Bell Telephone Company and became the parent company of the Bell System.