How To Drive A Motorcar
A Key To The Subtleties Of Motoring

THEORY OF GEARING consequently bring into use a crowbar. Having got the crowbar under the rock and placed a stone or similar fulcrum on which to exert the leverage which we are going to put into the crowbar, it is still found impossible to move the rock which we are anxious to get rid of. Obviously, the next step is either more power in the shape of an assistant on the “ business end ” of the crowbar, or, if an assistant is not forthcoming, then a longer crowbar. It will be found that the power which the person in the imaginary case is capable of exerting at his maxi- mum output, although failing to remove the rock with A simple example of the value of leverage obtained by a small pinion working into a large one. a small crowbar, is still, by bringing into use a longer one, capable of easily accomplishing the work. That is to say, that with a given capacity of power output he is able to accomplish work with big leverage which he cannot do with small leverage. Bringing the simile nearer the subject matter under consideration, the ratio of gearing is such a thing that when increased the engine is able to do that which could not be accom- plished. otherwise. Now, let the engine trying to drive the car up a steep 83 F‘2