Feb. 



1883.] 



KNOWLEDGE 



71 



screws on each row, a strap should also connect B to C, D 

 to E, and F to G. A and H will then become the terminals 

 to which the wires from other apparatus are connected. It 

 is clear that with all the straps joined across, the current 

 entering; at A will pass through those straps to H, instead 

 of passing through the coils, which the straps " cut-out " 

 or "short-circuit" Suppose it is required to insert a resist- 

 ance of 275 Ohms, then the straps over the 200, 40, 30, 

 3, and 2 Ohms resistance coils should be disconnected by 

 loosening the screws at one extremity of each such strap 

 and moving it out of contact. The current is then forced 

 to pass through the coils enumerated. By disconnecting 

 the side straps such as BC, we obviously break the circuit 

 or introduce a resistance of "infinity," and by disconnecting 

 all the three side straps, we can now use each row of 

 coils in a separate circuit. This resistance-bo.x, we shall 

 find, is very useful for Wheatstone Bridge, and similar 

 experimenta 



NOVELTIES IN TRICYCLES. 



By John Browxixg, 



(Treasurer of llie London Tricycle Club.) 



THERE are sufficient novelties in the Stanley Show of 

 Bicycles and Tricycles, which is held all this 

 ■week at the Albert Hall, to ensure the success of half-a- 

 dozen such exhibitions. Yet, the novelty is almost exclu- 

 sively in tricycles, showing conclusively which way the tide 

 is running. Only one novelty — a new kind of gearing — 

 has been applied to a bicycle, and that is an after- thought. 

 It was invented for the purpose of gearing tricycles up or 

 down at pleasure, and it is called the Crypto-dynamic 

 gearing ; it gives to bicyclists a power they have never had 

 before. 



In this brief notice I cannot do much more than name 

 the novelties, reserving my descriptions and criticisms for 

 further articles which the editor of Ksowledce has kindly 

 asked me to writ* for him. 



I would not in all cases wish it to be understood that I 

 recommend everything I name on the score of novelty. 



There is some amount of misplaced ingenuity, but for 

 ingenuity well applied I would specially name the Sterling 

 tricycle, by Adam Burdess. For moderately high speed, 

 comfort, and safety, I think this open-fronted rear-steerer 

 the best in the show. Next to it I would mention Rucker's 

 improved rear-steering tricycles, though I only place them 

 next because I consider Burdess's method of back pedalling 

 to drive forwards gives a power of hill-mounting which 

 cannot be obtained equally w-ell in any other way. 



First for speed I would name the new models of the 

 Humber tricycle. For graceful appearance and exquisite 

 workmanship they are almost unequalled. But, lest my 

 numerous readers in Knowledge should suppose that 1 

 recommend this tricycle before all others for their adoption, 

 let me remind them that comfort and safety ought to be 

 studied when they select a tricycle, as much as speed and 

 appearance. The so-named Ladies' Humber fairly com- 

 bines all these conditions. -It is as well adapted for 

 gentlemen as ladies. 



There is little room left for me to do more than mention 

 the names of the leading novelties. I would direct atten- 

 tion, while there is yet time to inspect them, to the 

 " Weston " tricycle, a new double-driver and front-steerer 

 of excellent workmanship and admirably planned. The 

 "Diana" tricycle, a doul)le-driving front-steering machine, 

 driven with balls on wire instead of a chain. This 

 machine is geared so that it can be driven either as a 48" 

 or as a 35", and it is a double-driver, with either gearing. 



The " Orbicycle " is an excellent machine ; a double- 

 driver without a chain ; but it is unnecessarily heavy. 



The special J)evon tricycle has a swing frame, which 

 enables the rider to place himself at will at any angle of 

 the machine, so that he can ride vertically with full 

 power up-hill. W. Keen it Co. exhibit Kinnaird's patent 

 action for bicycles and tricycles ; a contrivance by which 

 about G" throw in the crank can be used with less than 

 9'' rise and fall of the foot. 



Singer &, Co. exhibit the lightest and most compact 

 Sociables for two riders, and also a most novel tricycle, in 

 which the whole three wheels steer. 



The whole of the exhibits were not in position while I 

 was taking these notes. 1 may, therefore, have to name 

 two or three novelties next week. 



TuE Zeilung des Verehu Deni^cker Eisenbahn-^'er- 

 ivaltungen (Berlin, Jan. 12) has received from its Russian 

 correspondent the following details of the working of the 

 Trans-Caucasian railway during the first half of 1882. 

 This line, which is under the control of the Minister of 

 War, carried the following Government traffic, of course 

 without payment : 6,78G men, 1,1. 3o tons of munitions of 

 war, 12, .53.5 tons of military and other stores, 586 horses, 

 109 transport, itc, waggons, and 1.3 head of cattle. The 

 ordinary paid traffic for the same period amounted to 7,748 

 passengers, with about 19 tons of baggage, 4 vehicles, 38 

 horses, 2,659 head of cattle, and 1,818 tons of ordinary 

 goods. The total receipts (including X732 received for 

 conveyance of mails) amounted to .£3,900. The writer 

 remarks that there can be no question as to the working 

 expenses exceeding the receipts by at least five times their 

 amount. 



The Study of Locic. — A question has been raised of 

 late as to the value of the study of logic to improve the 

 reasoning powers. If by the word logic is meant what is 

 usually called formal logic, I venture to say — from an 

 experience of my own — that the effect of such study is not 

 good, that while it is in progress the reasoning powers are 

 apt to deteriorate, and that in all probability they will be 

 permanently diminished if the study of logic continues too 

 long. I observed — and I find others have noted the same — 

 that when much time had been given to the investigation 

 and classification of the various forms of syllogism, the mind 

 became apt to interrupt the reasoning process for one of 

 classification, noting to what class any syllogism that pre- 

 sented itself belonged, rather than considering (what 

 requires no logic to determine) whether the syllogism were 

 sound or not. The efl'ect might be compared to that of the 

 careful explanation of the movements involved in rowing, 

 skating, and swimming, in the case of one already able 

 to row, skate, or swim fairly well. Such a one, in his 

 anxiety to follow serial iin the movements explained to him, 

 is very apt to perform them far less satisfactorily than he- 

 did when he went through them without thinking about 

 them at all. As Macaulay remarks in his " Essay on 

 Bacon," a sensible man reasons in Barbara and Celarent all 

 day long without thinking about the matter. Set him to 

 note carefully what he is doing, and you give his mind 

 work to do which in no sense advances his reasoning. Few 

 men have enough extra brain energy in them to go through 

 this unnecessary mental work without disadvantage. But 

 the study of the various lines of false reasoning into which 

 most men are apt occasionally to fall, as arguing in a circle, 

 forgetting the point at issue, or begging the question — this 

 is at once useful and interesting. — Richard A. Proctor, 

 in Newcastle Weekly Chronicle. 



