Rough and Tumble Engineering

In order to get the learner started, it is reasonable to suppose that the engine he is to run is in good running order. It would not be fair to put the green boy onto an old dilapidated, worn-out engine, for he might have to learn too fast, in order to get the engine running in good shape. He might have to learn so fast that he would get the big head, or have no head at all, by the time he got through with it.