. Scientific American Volume 78 Number 01 (January 1898) . h thenact upon a system ofsmall levers and releasea clock mechanism. Thelatter serves to rotatethe two controllingdisks, which, by meansof make and break con-tacts, ring up the callcorresponding to thelocation of the fire andshow the correspondingnumber in the annun-ciator. The disks areso arranged that theyrepeat the alarm at thecentral station. A valuable feature ofthis cable is that it formsan effective burglaralarm ; for if a burglarshould attempt to de-stroy the ordinary win-dow alarm by breakingthe window glass andcutting the wir
. Scientific American Volume 78 Number 01 (January 1898) . h thenact upon a system ofsmall levers and releasea clock mechanism. Thelatter serves to rotatethe two controllingdisks, which, by meansof make and break con-tacts, ring up the callcorresponding to thelocation of the fire andshow the correspondingnumber in the annun-ciator. The disks areso arranged that theyrepeat the alarm at thecentral station. A valuable feature ofthis cable is that it formsan effective burglaralarm ; for if a burglarshould attempt to de-stroy the ordinary win-dow alarm by breakingthe window glass andcutting the wires, thepliers will form a metal-lic connection betweenthe inner and outerwires of the cable andclose the circuit, asshown in our illustra-tion. To avoid error in connecting up the return wiresthey are made in different colors. Thus the fire alarmwires are of copper, another set are copper wires tinned,land a third will consist of alternate tinned and copperwires (see Fig. 1). To keep down the bulk of the re- Vx^^^ S. Wiring for house fire-alarm connected.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectdevice, booksubjecttb
