The Montgomery advertiser., 1904-11-27

powder of the magnte keeps the dia-
 phraxm of the receiver vibrating, sett-
 ing in motion thee sound waves which fG4f upon the listeners ear.
 The thousands of transmitters and receivers which constitute part of the day.a work in the factory receive a great deal of careful attention after they have been finished. When new
 telephone is put in place by a Bell company anywhere in this country the
 subscriber receives an instrument
 which has been so carefully tested that 1t is known it will do good service whether the person using 1t be talking over d line one thousand feet or one thousand miles long Here in the fac- tory are men who spend their entire working day listening to the words which are flashed through the new in- struments The men who do this work | are especially selected after their hear ing has been rigidlys tested and they | become so expert that many instru- ments are rejected for variations in | the volume of fe quality of sound of | slight that no one else can detect them. | While every instrument Is known to | be capable of successful operation at | the end of thousand-mile line, it is | obviously impracticabis to have thou | sand miles of coiled wire in a single | room. so thes engineers have devised an ingenious apparatus which develops 1 an amount of resistance as the tele- phone current flows through 1t equal to that found in a line of the desired length. Voice-saving methods are used to assist the testers in their work and the man who holds the new re- ceivsrs to his ear listens to the tones of a photograph. The tests are made with those of a known capacity but so highly trained are the specialists in this part of the work that merely lis- tening at the receiver shows them at once even a slight defect.
 The making of transmitters and rec ceivers is small part of. the activities in this busy establishment with it's 4000 employes' One floor of the great building is almost entirely given up toI the assembling of portions of eele- phone apparatus Of which the public knows little. Here. for instance are hundreds of khoakands of electric ilshtI bulbs, each no bigger than the end of a lead pencil. These, when placed up- on switchboard, 15.0O0 being requir- ed in a single standard board, as they glow and are extinguished. give notice when people desire to talk over their lines and when the conversations are ended. In the lower floors of this New York plant are machines which, work ing with great rapidity and exactness, take the raw material and fashion it Into the hundreds of small parts which so to make up the completed appara- tus.
 And yet only a small portion of the work ofstelephone equipment Is done In the New York factory. An equal amount of the necessary apparatus, inI cluding switchboards, telephone boxes, cords and cables, is made In the Chica- so factories of the Western Electric Company. Here. as in New York, the visitor Is impressed with the delicacy of the work required in handling thel minute telephone Current, A switch board must be so constructed that the insulation shall be perfect in charac- ter. The thousands of miles of copper wire buried in the apparatus must all be wound with fine silk thread. or cov- cred with rubber insulation, While where the wires join, that there may be no loss of energy and no interfer- enee from other electrical impulses, the union must be made with bits of sol- der, there being over 100000 of these joints in a standard board. There is hardly a mechanical trade which Is not represented in the manufacture of the Bell telephone apparatus, and most Of the machinery has been invented as required. Bits of steel and copper are stamped out and shaped by the hun dreds of thousands for use in the switchboards. Braiding machines are constantly at work making the fami- liar green silk covering of the wires which are exposed to view in houses and offices. The making of the tele- phone cable which appears to the or- dinary observer like a lead pipe invol- yes many interesting processes, for that leead covering must bee perfectly air-tignt and the wires within it free from moisture These wires, as many as 1900 being placed in a single cable, are each wrapped in paper and after this is done and they ore assembled In the sheath they are thoroughly cooked in a huge oven to drive out any trace of moisture. The finer work of construction carried on in Chicago is done in a factory building which af. lords over 21 acres of floor space and accommodate nearly 5000 employees.