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

GETTING INTO SECOND GEAR being that the engine begins to drive round the wheel (a), which in turn makes b revolve at half the speed, and then the wheel (h) drives the wheel (c), once again reducing the speed as compared with the engine. If, for the sake of argument, the small wheel (h) has only 10 teeth and the big wheel (c) has 50 teeth, obviously the wheel (c) will only revolve once for every five revolutions of the wheel (h) ; in. other words, great lever- age is provided. In addition to this, however, we have assumed that the constant-mesh gears already make a gear reduction of 2 to 1, so that if the engine is going 1000 revs, the wheel (b) is only making 500, and h likewise goes at 500, the wheel (c) only goes at 100 r.p.m. This double reduction constitutes the great leverage previously- referred to. > It is soon found, however, that the road conditions warrant a change into a higher ratio, and we have naturally to look for the second gear. This will be made up naturally by the next smallest wheel on the layshaft, and the next largest one on the primary shaft, remembering, of course, that the constant-mesh pinions never change. Therefore it is necessary to make the wheel (d) engage with the wheel (i). Obviously, however, these two wheels could not en- gage at the same time as the low gear ones, so that before they are made to engage we have to declutch and move the wheel (c) out of engagement with the wheel (h). Therefore, we again take our change-speed lever and bring it from where we put it before into neutral position, which has the effect of pushing wheel (c) forward towards the engine so that it is out of engagement with wheel (h), by which time the wheel (d) is getting quite close to wheel (i). We must re- member now that when we were travelling along a few moment® ago on the first gear the layshaft (1) was re- volving at 500 r.pjn., whilst the primary shaft (m) was only revolving at 100 r.p.m., that is to say, the lay- shaft was doing five times the speed of the primary shaft. If, now, the second-speed gear wheels (i and d) have 87