FEa 24, 1882.] 



♦ KNOWLEDGE 



355 



advantage would be gained by the directors prohibiting 

 the fixing of any advertisements whatever, until the ex- 

 Iiil)its they refer to are duly placed in position, or some- 

 thing approaching thereto. The most notable advances 

 are in electric lighting. The Brush Company, to which 

 reference was made last week, have got all their live engines 

 in ifitii, and three of them running. 



The visit of the Lord ^layor two or three weeks since 

 has caused considerable delay in the general preparations, 

 some of the now unprepared firms ha\ing had (in order to 

 contribute towards making a display suitable to the occa- 

 sion), to start their engines before the concrete foundations 

 had dried ; consequently, these foundations were pulled to 

 pieces and had to be re-laid. In the Italian Court is one 

 of the prettiest exhibits conceivable. It consists of a brass 

 chandelier of delicately chaste design, decked with forty- 

 two incandescent lamps of the British Electric Light 

 Company. They are very regular, and appear to have 

 been carefully selected. Although the light from them 

 thoroughly illuminates the court, still greater eflect is to 

 be produced, as the Company is at present using only one 

 .'^-horse-power engine to maintain seven Brockie (arc) lamps, 

 in addition to the forty-two incandescent lamps. When all 

 is in working order, there will be two more engines at work, 

 each of lO-horse-power. 



Consequent, presumably, upon the serious railway acci- 

 dents which have so alarmed Londoners lately, great 

 attention is centred on the various exhibits for improving 

 our systems of signalling, Ac. In the Eastern Gallery, far 

 away from the general bustle, is a working model of a system 

 invented by Mr. King, of Paixton, Derbyshire, exhibited 

 by the Electric Railway Signal Company. The model 

 illustrates the working of three signal posts controlling a 

 main line and a branch line connected with it. There is a 

 treadle between the rails opposite each signal post and in 

 connection wth it. A train in passing over the treadle 

 connected to, say signal-post A, puts that signal, by a me- 

 chanical contrivance, to danger — that is to say, the line is 

 automatically blocked to a following train. The signal cannot 

 be lowered until train No. 1 passes signal-post B, in passing 

 which, by pressing on the treadle, it puts post B to danger 

 by mechanical means, and, simultaneously, by completing 

 an electrical circuit, lowers the signal at post A. Train 

 No. 2 is therefore at liberty to pass post A, but cannot pass 

 post B until train No. 1 has passed post C, and so on 

 throughout the line. If the train has to go on to a branch 

 line, the lever operating the points interlocks with the 

 signals, in this case V)locking the main line and clearing the 

 Iwanch. These signals can be reversed (that is to say, the 

 main-line signal cleared and the branch line signal blocked) 

 only by altering the lever. It is evident, then, that by this 

 system there cannot be two trains in any one section of the 

 line at the same time, unless the driver of one of the trains 

 ignores or fails to see his signal. 



An arrangement is also shown by which a train, in 

 passing a signal box, puts the minute-hand of a clock back 

 to zero. The hand then travels on for fifteen minutes, or 

 until the following train puts it again to zero. In this 

 way, the driver, as well as the signalman, can see how long 

 a time (up to fifteen minutes) has elapsed since the jiassing 

 of the preceding train. Another arrangement (not shown 

 in the model) is to indicate the numlier of trains passing 

 daring the twenty-four hours, and the time at which 

 each passed. While, however, several high autho- 

 rities express a wish for a good automatic system, 

 some of the railway officials appear to desire an 

 proved system of hand-signalling. The King patent 

 1 '•adily adaptable to this form, and it is to be hoped 

 "iiat before long we may see such a system as this in 



general use. The application of tliis or any other new- 

 form must be a process of time, considering the radical 

 change that would be necessary in existing apparatus, and 

 the large outlay involved. Until the system is tried, it is 

 somewhat difficult to form an opiiiion of its practicability, 

 although to all appearance it is as perfect for clear- 

 weather signalling as can possibly be desired. It does 

 not attempt to overcome the difficulties accompanying 

 foggy weather ; and here is apparently its weakest point. 

 In the North Nave, however, is a model of apj^aratus 

 designed for this purpose, and exhibited by the Biitish 

 and Irish Telephone and Electric Works Conipau}-. The 

 model is designed by Mr. Radclifle, of Birmingham. 

 He makes some use of electricity. Near the signal-post is 

 an electro-magnet (51 Fig. 1), over tliis is a ])iece of soft 

 iron (A), which, when a current of electricity passes 

 through the electro-magnet, is drawn downwards. When 

 the current ceases, a spring (S) draws A up again. 



Attached to A is a short rod, carrying a block of iron, 

 brass, or any durable substance (B). When the signalman 

 pulls his lever over to drop the signal-arm, the electrical 

 circuit is completed; so that A, and with it, B, are drawn 

 down. Attached to the side of the engine is a lever, or 

 simple rod of iron (represented in section by E), 

 which, if drawn down, acts by means of a spiral spring 

 upon a miniature signal-arm on the driver's platform, 

 within a few inches of his eyes, actuating at the same 

 time his whistle. If the signal is " down " when the 

 engine approaches the magnet, B only touches E, which, in 

 passing under B, simply shakes the miniature arm. If, 

 however, the signal is to " danger," A is drawn do^vn by 

 the current, and B presses the rod E down, and so puts 

 the miniature arm to danger, and by simultaneously blow- 

 ing the whistle, draws the attention of the driver to the 

 position of the signal and the attention of the signalman 

 to the position of the train. 



This, then, if found practicable, is an efficient substitute 

 for fog-signals. It is very simple and ingenious, and it is 

 to be hoped it will prove effective, at least in crowded 

 districts, where the trains, although frequent, do not travel 

 at a very high speed. It is more than possible, we fear, 

 that there may be difficiUties in the way of applying 

 the system to fast trains. 



Revolution i.\ a Ueed of Df.er. — For years an old buck, tlio 

 leader of the deer herd on the Boston Common, has maintained an 

 absolute and malicious tyranny over the younger member.^ of his 

 own sex. His treatment rankled, and the other day, wlien he shed 

 his horns, tiiey inadea combined attack upon liim, which only ceased 

 upon the death of the tyi'ant. The Superintendent and his 

 assistants attempted to interfere, but were driven nut of the in- 

 closore by the infuriated animaKs, which became docile again when 

 their enemy wivs dispo.i^ed of. They still prcseri-e. however, a sort 

 of sic /temper tyranniit air, and thus far, no one of their number lias 

 laid claim to the primacy. — Scientific American. 



