BICYCLES AND TRICYCLES. 



81 



either side the fore- wheel, has ball bearings for 

 the axle, and extending upward has a cross-bar 

 or handle parallel with the axle below, and 

 of greater length; the fore-axle is provided 

 with detachable cranks, oppositely projecting 

 from its outermost ends at right angles with it, 

 which bear on their 

 loose pins rubber - 

 covered pedals. The 

 whole is so con- 

 structed and propor- 

 tioned as to be pro- 

 pelled, guided, and 

 preserved in equilib- 

 rium, by the hands 

 and feet of the rider, 

 who has his position 

 a little behind a per- 

 pendicular line pass- 

 ing upward through 

 the axis of the fore- 

 wheel, and so almost 

 directly over the 

 wheel. The radius 

 of the fore-wheel is 

 about the length of 

 the rider's leg, meas- 

 ured inside to the 

 ball of the foot, less 

 the length of the 

 crank and the height 

 of the saddle above 

 its periphery. The 

 vehicle is so light as 

 to be easily porta- 

 ble (the weight of a 

 fifty - inch machine 

 being about forty 

 pounds), and so elas- 

 tic as to prevent the 

 dangerous shake and 

 jar incident to a rigid 

 machine. It is mainly 

 one wheel, with the 

 necessary adjuncts to 

 make it operative. 



There are several varieties of vehicles popu- 

 larly known as bicycles, which differ in some 

 respects from the one described above; the 

 main object of their construction being to give 

 additional safety to the rider. The principal 

 varieties may be described as follows: 1. A 

 machine having the small wheel in front, to be 

 used for steering. The motive power is trans- 

 mitted to the driving-wheel by two levers, one 

 on each side of the wheel, which are con- 

 nected by leather straps wound around the 

 hub to two sets of gravity pawls and ratchets. 

 2. A small machine having a forty to forty- 

 eight inch fore-wheel, and the rear- wheel trail- 

 ing at a considerable distance behind. The 

 fork is extended about twelve inches below the 

 bearing of the fore- wheel, and projects slightly 

 forward, and to its lower extremities are fast- 

 ened pedal-levers to which secondary cranks 

 connecting with the axle are jointed. 3. A 

 VOL. xxiv. 6 A 



similar machine, having the fork extended in 

 the same way, but instead of having pedal- 

 levers it has cogged-wheels with cranks at- 

 tached, connected by means of an endless chain 

 to similar smaller wheels at the bearings. This 

 is called the Kangaroo. 4. A machine having 



THE BICYCLE. 



a driving-wheel of the standard size, and a 

 driving apparatus, consisting of short arms 

 working on universal joints at the sides of the 

 fork, to which are jointed bent levers, these 

 being fastened at about their centers to the 

 cranks ; the part below the crank, curving back- 

 ward until it is perpendicular to the upper part, 

 terminates in the pedal. This is known as the 

 'Xtraordinary. 



The bicycle, although seemingly a simple 

 thing, is in reality a complex structure, and 

 embodies some of the finest results of modern 

 mechanics, and, as ordinarily constructed, con- 

 tains nearly three hundred pieces. Only the 

 most important parts, with their principal vari- 

 ations, need description. 



The tire is of rubber, round, and of various 

 qualities and densities, and varying in thick- 

 ness from one inch for the heaviest roadster, 

 to three-eighth inch for the lightest racer ; it 



