Stoney — On Gearing for Bicycles and Tricycles. 21 



allowing an inner axle, to whicH the cranks are keyed, to run 

 freely within it. To one side of the hub a sun- wheel is fixed, into 

 which a planet-wheel, mounted on a pin near the end of one of 

 the cranks, is to work. If this planet-wheel be fastened to the 

 crank so as to form one solid piece with it, the machine will 

 be geared level in the way that is suited to hill- work. In this case 

 the wheel of the machine, with its sun-wheel attached, the crank 

 and the planet- wheel will all form one solid mass, which will turn 

 together without any relative movement. On the other hand, if 

 the planet- wheel is fastened to the lever or connecting-rod of the 

 ■bicycle, it will continue to be carried round by the crank, but will 

 be kept from turning round with it, and accordingly it will drive 

 the sun- wheel at a speed which is determined by the numbers of 

 teeth in the sun and planet- wheels, and which can be made what- 

 ever the maker pleases. A proper appliance should be provided, 

 which will enable the rider at will to connect the planet-wheel 

 either to the crank or the lever, and he can thus drive his machine 

 level when he connects the planet- wheel with the crank, or geared 

 up when he connects it with the lever. 



II. The next contrivance is one for attaining the same end, 

 and is suited to machines with levers something like those of the 

 'Facile.'- Cogged wheels are to be keyed on both ends of the axle 

 of the bicycle wheel; each of these is to work into a cogged wheel 

 placed immediately above it, and running on a pin screwed firmly 

 into the fork of the bicycle. Each of these cogged wheels is to be 

 provided with a pin projecting from its face, over either of which 

 the connecting-rod from the lever may be hooked. If the connect- 

 ing-rod is hooked to the lower wheel it will drive the machine ' level,' 

 and the upper cogged wheel will run as an idle wheel, doing no 

 service, but doing no harm. If, on the other hand, the rider hooks 

 the connecting-rod to the upper cogged wheel, his foot will drive 

 that cogged wheel, which in turn will drive the lower one, and 

 with it the bicycle wheel to which it is attached. The number of 

 teeth in the wheels will of course then determine the speed. 



It would be a great convenience if the rider could alter the 

 gearing without dismounting ; and this might be effected if con- 

 necting-rods hung permanently from both the wheels, with a cross- 

 rod joining their lower ends. This cross-rod should pass through 

 an eye attached to the lever on which the foot works, and should 



