Crossley's Modification of Hughes's Microphone

Abstract

EVER since Hughes's discovery of those principles which led to his invention of the microphone, inventors have been trying to improve the instrument by adopting every variety of form and employing every combination of apparatus that were likely to lead to good results. The failures must have been legion, and of the successes the members of the British Association have had during their stay at Sheffield, an opportunity of examining and seeing at work perhaps the most efficient—Crossley's modification of the microphone. Six distant places—the two newspaper offices and four meeting-rooms—were telegraphically connected with the Cutlers' Hall, where a switch-board stood to place any two distant stations into communication, thus illustrating the exchange system so largely employed in America. Every one is aware that with the telephone the speaker has to hold the instrument to his mouth; With the Crossley's transmitter, however, conversation, a few feet away, is readily conveyed. The transmitter is now being largely employed in the United Kingdom, and it is found that where telephones alone are useless because of the induction of adjacent wires, the instrument acts admirably. The undulatory current produced by sonorous vibrations is so intense that a person speaking about a foot away from a transmitter has been heard ten feet from an ordinary telephone in Manchester thirty-six miles away by wire, and this although the induction from some thirty adjacent wires had to be overcome, and we may add that the intensity of the sound may be largely augmented by employing increased battery power.