. Electricity simplified. The practice and theory of electricity ... nd easily disturbed is clear that every change in the nature of thiscontact will change the intensity of the current. Ifthe blocks or the table they rest on is disturbed, evenby being spoken at, the disturbances will produceminute changes in the current which will reproducethe disturbances and corresponding sounds in thetelephone diaphragm. Of all substances carbon seems the best for theloose microphone contact, and is universally great variety of microphones have been invented,almost all depending on loose
. Electricity simplified. The practice and theory of electricity ... nd easily disturbed is clear that every change in the nature of thiscontact will change the intensity of the current. Ifthe blocks or the table they rest on is disturbed, evenby being spoken at, the disturbances will produceminute changes in the current which will reproducethe disturbances and corresponding sounds in thetelephone diaphragm. Of all substances carbon seems the best for theloose microphone contact, and is universally great variety of microphones have been invented,almost all depending on loose carbon contacts. Asimple form is shown in the illustration. In it C Care blocks of carbon between which a spindle of car-bon A is sustained in very loose contact. The base 144 ELECTRICITY SIMPLIFIED. X Y are the D serves to support the instrument,ends of the line wires. The mouthpiece in the ordinary telephone intowhich the transmitter of a message speaks is the frontof a microphone. The instrument held to the ear isa simple telephone. The handle turned to ring up. Fig. 29.—Microphone. the central office and the other subscriber actuates asmall magneto-electric generator, which rings thebell, calls up the operator at the central office, and,when contact is made, rings the bell at? the receiversinstrument. The whole telephone system, it will be observed,represents one phase of the transmission of power. THE INCANDESCENT ELECTRIC LIGHT. 145 Electric Lighting. When a current goes through a conductor, it heatsit. The degree of heating depends on the resistanceoffered to the current and on the currents given current will heat a conductor of small sectionto a high degree, while a large conductor will carrythe same current without much rise in this principle is based the incandescent electriclight. The lamp consists of an exhausted glass globe,containing a filament of carbon of high electric-light station, by means of wire of com-paratively
Size: 1792px × 1395px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidel, booksubjectelectricity
