Alexander Graham Bell had prepared himself to follow the professional footsteps of his father and grandfather in the teaching of proper articulation and the correction of speech defect. He became a teacher of speech to the deaf. Early in his training, his investigation into the nature of sound led him to study electricity. It was out of this work, together with his understanding of the organs of the organs of speech and hearing, which his invention grew.
He attempted to apply sound to telegraphy in a device called the harmonic telegraph. He hoped it would transmit several Morse messages tuned at differing levels over the same circuit simultaneously. While he was working with his device, Bell ...view middle of the document...
On the evening of that day, as the younger inventor prepared a crude experimental transmitter to try sending his voice over a wire to a room down the hall where Watson was listening, he upset the acid of a battery. It spilled over his clothes. Impulsively, Bell called out, ‘Mr. ,Watson, come here, I want you.’ An instant later Watson burst into the room shouting ‘Mr. Bell, I heard every word you said!’
Bell exhibited and demonstrated his telephone at the Philadelphia Centennial in June, 1876, where it won the enthusiastic approval of leaders in the scientific world. But the general public showed little interest. The young inventor had no financial backing other than of Thomas Sanders and Gardiner G. Hubbard. In the fall of 1874 these man had agreed to supply funds for Bell’s telegraph experiments in return for a share in whatever patent rights might result from his experiments. His telephone patents were later included in this agreement.
Figure 1: Models of first Bell’s first pone and the newest Bell telephone known as ‘500’ set
Bell’s first telephone patent had been granted on march 7, 1876, but was earning no return. In order to eke out his small personal income as a teacher, and to provide funds for further experimentation, Bell began, early in 1877, to give lecturers at which he demonstrated the telephone. In May, 1877, the first telephones were put into use on a commercial basis.
Two years later, in April 1880, the American Bell Telephone Company was organized. It greatly developed the telephone organization and business throughout the country. A line from Boston to Providence was built in 1881. Service between Boston and New York, 235 miles, opened in 1884.
After Alexander Graham Bell carried on his first successful experiments on the electric speaking telephone a real research began. From Bells modest beginning has evolved the Bell Telephone Laboratories of today, where over 8 000 scientists, engineers, technician and other specialists constantly seek ways to improve telephone services and widen its usefulness and keep low cost.
The use of wires instead of a single, grounded wire greatly improved transmission and made it possible to talk longer distances. This increased the demand for the service but also increase number of wires strung on telephone poles. The large number of wires on towering poles along city street began to cast shadows of doubt on the prospects for further growth. Compact cables had to be developed and a way found to run them underground. Years of painstaking and study trial accomplished this. Cable development illustrated the dollar value of telephone research. The standard cable of 1888 contained 50 pairs of wires and cost more than $150 per pair-mile to install.
Bell scientists were the first to develop a practical amplifier tube which placed at intervals in long distance, restored the energy of weakening voice currents, making it possible to telephone from coast to coast.
Figure 2: Bigger than a man’s hand,...