The Birmingham age-herald., 1906-11-04
certain exacting standards which engi- neernig necessity has imposed.
 Maunet In Receiver


 neerng necessity has imposed.
 Magnet In Receiver.
 The same truth applies to the other ele- ments of the receiver-as to the perma- nent magnet made of a special grade of magnet steel, rolled in Pennsylvania mills and bought for the New York factory in fifty-ton lots with surprising frequency. In each receiver the pole pieces at the end of the permanent magnet represent fine quality of what is known in the trade as Norway iron-though it Is actu- ally for the most part produced in Sweden. The. paper insulation of the spools demands the finest kind of bond made in the Berkshire Hills, in the home town of the junior senator from Massa- chusetts.
 Many a telephone subscriber has won dered what is in the center of the re- ceiver. If he looked inside he would find there a plummet weighing about one third of a pound-a small weight in the single instrument, but one that must reach total of in the neighborhood of 100000 pounds tied up in the receivers of the Bell system. Nearly all this is American lead mined in Illinois, Mis- souri and other states.
 Then. there is the ferrotype diaphragm which conveys vibrations to the air. It is simply a very thin sheet of japanned iron. In each of the bi-polar coils are
 
 with silk About 175 miles of this tiny thread is sent out daily, or more than enough in the receivers of one years production to stretch twice around the globe This wire is insulated with the best silk obtainable in the market. The 1 little brass screws used in the receiver 1 do credit to the clever workmanship l of the factories of a Connecticut cor ! poration.
 l Contents of Transmitter. 1 similar tale is to be told of the con- ] tents of the transmitter, with differ l enee for these two nstrumetns which 1 are made for use Of the companies or 1 the Bell system have, of course, differ l ing characteristics according to their em- ployment The mouthpieces, for example, of the transmitter are no longer of vulcan l ite as they were some years ago. They are fashioned from a composition of the , same general characteristics and appear l ance, but superior in certain respects for | the purposes of the instrument. Then, l too. there is a diaphragm made of sheet 1 aluminium, a metal the existence of which 1 was predicted by the strange Swiss l genius. 4Paracelsus, the last of the alche- l mists who uttered a striking prophecy when he declared that the well known l mineral alum had a metallic base. Three | hundred years later 1t was duly diseov- cred In the old days it's cost would l have made it prohibitve for the purposes | of the telephone manufacturer, for in 1856 q pound of it cost $300. Today it is down to a point where it is less than | twice as expensive as copper, and where | the makers of the telephone are able to get the benefit of it's lightness and it's l extreme ductility and malleabilty. It 1 comes from Pittsburg.
 1 In the button of the transmitter are l carbon electrodes, and one also finds | particles of a very fine quality of gran l ular carbon which the Western Electric | company manufactures for it's own uses 1 This is one of the absolutely essential ! components.
 Brass Used.
 For the rest there are in the transmit ter little rubber cushions and blocks and rubber bands as well as special springs which hold the diaphragm in place. In the whole head" the engineers term it, one finds actually about one and three 1 eghths pounds of brass. Multiply that weight 25 4500. the number of transmit ters turned out in day, and that again by the number of working days in the year. and you will get formidable total, | one that helps to explain why every cop per mine in the United States is being l worked to it's utmost capacity and why ] the brass manufacturers of the Nutmeg | State are pressing into service all the ! skilled laborers they can secure.
 The outside stand of the transmitter, i which is not counted in the instrument output is, at the same time, an 1mpor- tant part, involving the use of great i quantities of the metals which, though not called precious, are nevertheless 1 coming to be regarded by the electrical industries as belonging nearly in the 1 semiprecious class, The very obvious nickel plating recalls the story of the l honesty of New York chemist who