240 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[July, 



rig. 6 



Terminal Telegr.-pli. 



Kig. 7. 



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2.F 



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Fig, 8, An [ntermeiliatc and Toririble Telcgiaph. 



Section of Rail» ay. 



Ki^. 10, The Electric Delcclor, for detecting injury caused to the «ircs, i-c. 





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Fig. 9, Telegraph of a simple form. 



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I 



I ! 



CLEAR. STOP 



Tij.i. 



bolt rests upon the arm of a lever supported by a spring ca- 

 palde of offering a resistance equal to at least half the pressure 

 of one wheel of a carriage. 



Upon a train passing, one arm of the lever is depressed, 

 which, raising the other arm, breaks the electric circuit at e, 

 and causes the alarum to be sounded and the warning signal 

 to be given at A and D ; the other wheels of the train produce 

 no further etfert till the warning has been replied to from D, 

 which at the same time restores the electric circuit of the 

 " warner " for another signal. Though the " warner " might 

 be let off by mischievous persons with a crowbar, no incon- 

 venience would be occasioned beyond arousing the expectation 

 of the policeman for the time occupied by a train in passing 

 the space between E and A, when the fact would be dis- 

 covered, and reported by a signal to D. The object of the 

 " v>arner " may obviously be attained by a variety of simple 

 mechanical means. 



Figs. 6 and 7. — Terminal telegraphs, for more extensive 

 communications than those already described, giving 30 or 60 

 signals by the pointing of a revolving index-hand at letters on 

 a fixed dial, as in a common clock ; the person giving the sig- 

 nal turns the concentric hand t, till its pointer stands opposite 

 the signal to be given, as shown in Fig. 6, when instantaneously, 

 the index hand g in all the corresponding telegraphs in the 

 circuit, viz. Figs. 0, 7, 3, &c. point at the same signal. Fig. 8 

 is an intermediate and portable telegraph, to be carried with 

 each train, and applied, in case of need, to convenient arrange- 

 ments at each mile-post or bridge along the Kne. The section 

 of a railway below Fig. 8 illustrates this subject. An iron 

 cap to the mile-post being unlocked and taken off, the port- 

 able telegraph is place<l within a ledge fitted to receive it, 

 making thereby the necessary connexions with the conducting 

 wires, when it is at once fit for working with the " terminal 

 telegraphs." This form of telegraph can be worked by any 

 person at first sight, and requires no battery to be carried 

 with it. It is fitted up with a water-proof cover and lantern, 

 for rainy weather and niglit use. 



N.B. — All forms of this electric telegraph are " reciprocal " 

 in tlieir action i. e. they give the same signals, in the working 

 as in the recipient apparatus, and work equally from either 

 end or from intermediate points. 



Fig. 9 represents a very simple form of telegraph, on ex- 

 actly the same principles as Figs. 5, 6, and 7, but combining 

 the powers of both ; the arrow giving two signals, for the pur- 

 poses explained when applied to tunnels, level crossings, &c., 

 and the small index K being adapted for a more extensive 

 communication, when circumstances require it. 



