the driver will have to change down two speeds to keep the car running properly. It is therefore highly necessary, before trying long drives in a hilly country, that this point should be thoroughly mastered. The same remarks apply in ordinary driving. It is always well to keep within the power of the engine, and after having stopped or slowed down it is advisable to change back to a lower speed so as to ensure the engine plenty of power to start the car again.
Accelerator.—It would perhaps be as well here to explain the use of the third pedal referred to before as the 'accelerator pedal.' While not essential to the proper running of the car, it can be made of considerable use in driving.
The type of motor carriage we have described is fitted with an engine which governs out at approximately 750 to 800 revolutions a minute. If, however, the governor is held up—and this is what the accelerator pedal accomplishes—of course the engine speed is considerably increased and the speed of the car is increased accordingly; but though the accelerator pedal is beneficial in the hands of a careful and considerate driver, it can be abused to the damage of the engine and gear in the hands of a rough or careless driver.
To race the engine on any and every conceivable occasion is obviously improper; but it will be found that to accelerate a little when wishing to change (but before doing so), especially when going uphill, will assist very materially in accomplishing the change of speed successfully.
Overrunning the Engine.—We will suppose that you are running down a steep hill with the speed lever set in the third speed—with the left pedal down and the motor consequently disconnected—and this third speed gives, say, a rate of twenty miles an hour. The car, however, from its own momentum and the force of gravity, may be running at twenty-five miles an hour, and to let the clutch in then throws a very unfair strain on the engine. It must be remembered that the engine has to drive the car and not the car the engine, which if caused to rotate at a much greater speed than that for which it was
