. The practical telephone handbook and guide to the telephonic exchange . to frighten the jokers. 508 A UTOMA TIC EXCHA NGES 5°9 S ^^P Another serious feature is that a smart business man,by certain easy operations is able to cause the line of a rivalto test engaged at important times, and thus interfere with hisbusiness. On the other hand, there are several important advantages,in addition to secrecy of working, claimed for complete auto-matic working—such as increased speed, facility for workingvery large exchanges (even up to as many as 1,000,000 lines,which are out of the limit of a ncdfiH
. The practical telephone handbook and guide to the telephonic exchange . to frighten the jokers. 508 A UTOMA TIC EXCHA NGES 5°9 S ^^P Another serious feature is that a smart business man,by certain easy operations is able to cause the line of a rivalto test engaged at important times, and thus interfere with hisbusiness. On the other hand, there are several important advantages,in addition to secrecy of working, claimed for complete auto-matic working—such as increased speed, facility for workingvery large exchanges (even up to as many as 1,000,000 lines,which are out of the limit of a single manual multiple board),and, in the case of large ex-changes, economy of first costand maintenance. Strowger System.—So far allinstallations of automatic ex-changes have been on the Strowger * system. Thissystem has been before thepublic for many years, but upto recently it had not mademuch progress. Small privateinstallations have for sometime been fitted in this coun-try— one at the MunicipalBuildings, Glasgow, and an-St BartholomewsLondon, but they. Fig. 470.—SubscribersInstrument have attracted but little other at Hospital, attention. Subscribers Set.—The apparatus supplied to the subscribersconsists of the usual transmitter, receiver, ringer, inductioncoil and local battery, with the addition of calling or selector apparatus for sending the requisite electricalimpulses along the 2-wire lines for operating the mechanismat the central office. Fig. 470 gives a front view of a stationwall set, with the selector mechanism fitted below the trans-mitter arm. The portion of the latter seen on the outsideconsists of a pivoted dial, provided with a set of 10 finger 5io PRACTICAL TELEPHONE HANDBOOK holes, numbered upwards from 1 to 10 or 0. This dial isconnected to a wheel with 10 teeth to correspond, and asingle tooth apart from the others, which serves a specialpurpose. The connections are shown in Fig. 471, whichshows the instrument in the normal condition. E
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
