Invention of the telephone hardly a commercially practical telephone in the modern sense. Thomas Edison tested the Reis equipment and found that "single words, uttered as in reading, speaking and the like, were perceptible indistinctly, notwithstanding here also the inflections of the voice, the modulations of interrogation, wonder, command, etc., attained distinct expression." In 1947, the Reis device was tested by the British company Standard Telephones and Cables (STC). The results also confirmed it could transmit and receive speech with good quality (fidelity), but relatively low intensity. At the time STC was bidding for a contract with Alexander Graham Bell's American Telephone and Telegraph
History of the telephone worked mainly on a store and forward basis. Although telephones devices were in use before the invention of the telephone exchange, their success and economical operation would have been impossible with the schema and structure of the contemporary telegraph systems. Prior to the invention of the telephone switchboard, pairs of telephones were connected directly with each other, which was primarily useful for connecting a home to the owner's business. A telephone exchange provides telephone service for a small area. Either manually by operators, or automatically by machine switching equipment, it interconnects individual subscriber lines for calls made between them. This