He was for five years a clerk in the office of an Irish land-agent, but came to London with his family in 1876, and in 1879 was, according to his own account in the preface to The Irrational Knot, in the offices of the Edison telephone company.
Edison also patented (U.S.A. Pat.
Both the Bell and the Edison Companies opened negotiations with the Post Office for the sale of their patents to the government, but without success.
The Edison Telephone Company of London was formed.
A telephone transmitter and a receiver on a novel plan were patented in July 1877 by Edison, shortly after the introduction of Bell's instruments.
Experiments very similar to these of Edison were made by Elisha Gray of Boston, Mass., and described by him in papers communicated to the American Electrical Society in 1875 and 1878.
Edison, the last-named inventor elaborating a type of meter which he employed in connexion with his system of electric lighting in its early days.
Edison in the United States, were engaged in struggling with the difficulties of producing a suitable carbon incandescence electric lamp. Edison constructed in 1879 a successful lamp of this type consisting of a vessel wholly of glass containing a carbon filament made by carbonizing paper or some other carbonizable material, the vessel being exhausted and the current led into the filament through platinum wires.
The first to attain practical success was Edison, and his method with some modifications is still the one in most general use.
Some curious distance-phenomena connected with electric sparks were observed in 1875 by Edison (who referred them to a supposed new " aetheric force "), and confirmed by Beard, S.
Edison Telephone Company, 6 Q.B.D., 244) that the telephone was a telegraph, and that telephone exchange business could not legally be carried on except by the PostmasterGeneral or with his consent.
The Edison electric meter, like those of Sprague and Lane-Fox, was based upon the principle that when an electric current flows through an electrolyte, such as sulphate of copper or sulphate of zinc, the electrodes being plates of copper or zinc, metal is dissolved off one plate (the anode) and deposited on the other plate (the cathode).
To prevent temperature from affecting the shunt ratio, Edison joined in series with the electrolytic cell a copper coil the resistance of which increased with a rise of temperature by the same amount that the electrolyte decreased.
Edison in 1878 again attacked the problem of producing light by the incandescence of platinum.
In 1879 and 1880, Edison in the United States, and Swan in conjunction with C. H.
Edison, moreover, as well as Lane-Fox, had realized the idea of a public electric supply station, and the former proceeded to establish in Pearl Street, New York, in 1881, the first public electric supply station.
Edison, with copious ingenuity, devised electric meters, electric mains, lamp fittings and generators complete for the purpose.
Alexander Graham Bell in 1876 invented the speaking telephone, and Edison and Elisha Gray in the United States followed almost immediately with other telephonic inventions for electrically transmitting speech.
- Edison Accumulator.
Almost simultaneously with Berliner, Edison conceived the idea of using a variable resistance transmitter.