Aug. 24, 1883.] 



* KNOWLEDGE ♦ 



113 



^^^^ MAGAZINE OF SCIENCE 



^UINUrvyORDED -EXACirfDESCRIEED 



LONDON : FRIDAY, AUG. 24, 1883. 



Contents op No. 95. 



PAQB 



Tricycles in 1883 : Small Wheels i-. 

 Large Wheels. By John Browning 113 



The Birth and Growth ot Myth. 

 XIV. By Edward Clodd Ill 



Sea Anemones. III. By Thomas 

 Kimber 115 



Pretty Proofs of the Earth's Rotun- 

 dity. (/«««.) By R A. Proctor 116 



How to Get Strong: Reducing Fat. 117 



The Comma. By R. A. Proctor ...118 



Chemistry ot the Cereals. IV. By 

 William Jago, P.C.S 119 



PAGE 



Sun-Views ot the Earth. (IlUit.) 

 By R. A. Proctor 121 



The Moon in a Three-Inch Tele- 

 scope [IUm.) By F.R.A.S 133 



The Fisheries Exhibition. V. 

 [Illus.) By John Ernest Ady ... 133 



COREESPONDENCE : Light ftom 



Flowers — Wart - Charming — 

 Magic Squares, &c 125 



Our Mathematical Column; Geo- 

 metrical Problems. XIII 127 



Our Chess Column 128 



TRICYCLES IN 1883. 



SMALL WHEELS v. LARGE WHEELS. 

 Bv John Browning, 



Chairman of the London Tricycle Cluh. 



IN a tricycling journal published this week, Mr. W. T. 

 Shaw, who is the patentee of a two-speed gearing for 

 which we have waited impatiently for nearly a year, 

 accuses me, though in most courteous terms, of lending the 

 weight of my name and official position to the promulgation 

 in Knowledge of erroneous opinions as regard.s the best- 

 size for the wheels of tricycles. 



Mr. Shaw states, at great length, that large wheels make 

 fewer revolutions on their axles than small ones, and also 

 that thoy pass with less resistance over obst;ieles in their 

 path. These facts are, of course, well known to every tyro 

 in mechanics. Mr. Shaw argues from them that tricycles 

 with large wheels will travel easier than similar machines 

 with small ones. 



I have no hesitation in admitting Mr. Shaw's state- 

 ments and denying his conclusions. As I am accused 

 of "propounding false theories and advocating the construc- 

 tion of ideal tricycles," I will confine myself in my reply 

 to practical and well-established facts, though there is not 

 one single sentence in the article to which I am replying 

 to lead a reader to suppose that the writer has (>ver ridden 

 a tricycle. 



Let me say briefly, that large wheels are very weak as 

 compared with small ones, unless they are made so stout 

 as to be e.\cessively heavy, and that this extra weight 

 greatly reduces the speed of the machine. 



The small wheels of tricycles are not greatly retarded by 

 obstructions, because the rims of our wlieels have soft 

 rubber tires, and most obstructions on the roads sink 

 into these. Neither the machine nor the rider are lifted 

 over them. Here is a proof; the Monarch is an excellent 

 machine, probably the best niadi; for very rough roads, yet 

 its driving-wheels are only 40 in. in diameter. If our 

 roads were strewn with Kentish Hints or brickbats then 

 large wheels might be necessary. 



Mr. Sliaw advocates, theoirtica/fi/, the building of 



" machines with driving-wheels of 56 in. or upwards in 

 diameter, geared level or down to 50 in., for ordinary run- 

 ning, with a second speed for hill-climbing, and a steer- 

 ing-wheel not less than 24 in." Such a machine, to be fairly 

 strong, would require to weigh from 1301b. to 1401b., if 

 not more. 



Now I have found that, with a machine which has 

 50-inch wheels, weighing from SO lb. to 90 1b., I must 

 gear down to 3G inches to travel easily, and my pace on a 

 journey which takes several hours will be from live to six 

 miles an liour. 



With a machine which has 38-inch wheels, weighing 

 from 501b. to 55 lb., I can gear u]) to 46 inches, and travel 

 for a greater number of hours at the rate of from seven to 

 eight miles an hour. In other words, wheels 1 2 inches 

 larger on a machine which weighs 30 lb. more reduces my 

 pace by two miles an hour, and the distance 1 can travel by 

 25 miles in a day. For, on the heavy, large machines, 

 from 30 to 40 miles in a day was a hard task for me, while 

 on the small light machines I can travel without fatigue 

 from 60 to 70. 



But look at the authorities I am supported by. Mr. 

 Marriott, a partner in one of the first, if not the leading, 

 firms of tricycle manufacturers, and our first long-distance 

 rider, uses a machine with 42-inch wheels, geared to run as 

 56 inches. Mr. S. Salmon, the Secretary of the London 

 Tricycle Club, whose experience in tricycles and tricycle 

 riding on roads is certainly not less than that of any man 

 in the kingdom, rides a machine which he has aptly named 

 the " Shadow," with 40-inch driving wheels geared to 

 48 inches, which weighs only 40 lb. Mr. Grace, of Anerley, 

 a most careful and thoughtful experimenter, who has several 

 machines of various sizes, considers (I am quoting his own 

 words) " 40 inches large enough for the wheels of any 

 tricycle." 



Mr. Arthur Salmon, one of the finest riders in the 

 London Club, who is 5 ft. 1 in. high, has for two years 

 ridden a machine with 52 in. wheels, and which weighed 

 961b. This year he is riding a machine of the same 

 pattern with 42 in. wheels which weighs 651b., and, after 

 six months' experience, he informs me that nothing would 

 induce him again to 'ride one of the larger and heavier 

 machines. Three years ago it might have been said truly 

 that I was urging the use of small wheels and light 

 machines theoretically. I was perfectly aware of their 

 disadvantages, and lielieved, as it is now seen correctly, 

 that they might, in mathematical language, be neglected. 



But now that manufacturers, experimenters, and riders 

 are agreed on adopting them, Mr. Shaw must give them 

 something more than an array of figures — he must give 

 them good reasons drawn from riding experience before he 

 can expect them to go back to plans which he proposes as 

 though they were new, but which they have already tried 

 and found wrong. 



Certain results I have obtained lead me to doubt if I 

 have yet reached the limit to which wheels may be reduced 

 with advantage. 



I shall very shortly have made for mc a single tricycle, 

 with 3G-in. wheels geared to 46, which will weigh about 

 45 lb., and a double tricycle with 36-in. wheels, which will 

 not exceed in weight 100 lb., and, should these be slower 

 tlian machines with larger wheels, I will acknowledge it. 



To conclude, I am charged with tempting makers to 

 build machines so light that they will be unsafe. Here is 

 my reply. At the commencement of this season, when 

 Messrs. Ilumber \- Co. kindly undertook to build me my 

 3S-in. machine, wliich weighs about 51J lb., to my own 

 specification, they stipulated that I should not ride the 

 machine on macadamised roads. Since then they havG 



