. Electrical world. he startingof any call by a subscriber, denoted by his removing his receiverfrom the hook, will be followed at once by the registration by auto-matic telegraphic means of his number, in dot-and-dash code, upona Morse register. To accomplish this signal the switch hook isgiven a long throw and moves under the influence of a heavy spring,the speed being controlled by a dash-pot. In its upward motion acontact piece attached to the hook trails over a series of properlyspaced contacts through which the code signal is sent in. On thedownward motion no contacts are made, as a defl
. Electrical world. he startingof any call by a subscriber, denoted by his removing his receiverfrom the hook, will be followed at once by the registration by auto-matic telegraphic means of his number, in dot-and-dash code, upona Morse register. To accomplish this signal the switch hook isgiven a long throw and moves under the influence of a heavy spring,the speed being controlled by a dash-pot. In its upward motion acontact piece attached to the hook trails over a series of properlyspaced contacts through which the code signal is sent in. On thedownward motion no contacts are made, as a deflecting springthrows the moving contact out of position. This particular type ofsignal would at first thought seem to be of no value; but it is probablydesigned to co-operate with its inventors telephone fire alarmscheme, which has been already described in these columns. PLUG EJECTING JACK. A switchboard jack designed to automatically eject a plug in-serted in it upon the sending in of a clearing-out signal has been. FIG. S.^FAHNESTOCK TRANSMITTER. 326 ELECTRICAL WORLD and ENGINEER. Vol. XLIII. No. 7- patented by R. G. Dunfee, of Fostoria. Ohio. The ejection of theplug is accomplished by a spring which becomes compressed by itsinsertion, being latched until the current from the ring-of? releasesits trigger through the agency of the clearing-out coil. The ap-paratus is probably, of far greater value in theory than in practice. SELECTIVE SIGNAL SYSTEM. Another step-by-step selective signalling system has appeared, thistime in a patent granted to G. Babcock, of Chicago, and assignedto the Stromberg-Carlson Company. This system has some featuresnot usually included in such systems, the most notable of which isan indicator to show the central office operator on disconnectionwhether or not she has restored the line to normal. Unfortunately,this signal is associated with the connecting cords and not withthe abnormal line, and the operator in order to correct any indicatederror, must r
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
