attend to his own business and let other people attend to theirs. That
a monkey wrench is a tool to be left in the tool box till he knows he
needs it. That muscle is a good thing to have but not necessary to the
successful engineer. That an engineer with a bunch of waste in his hand
is a better recommendation than an "engineer license." That good common
sense, and a cool head is the very best tools he can have. Has learned
that carelessness will get him into trouble, and that to "forget" costs
money.

Now the fellow who said "It is no trick to run an engine," read this
book another way. He did not see the little points. He was hunting for
big theories, scientific theories, something he could not understand,
and didn't find them. He expected to find some bright scheme to prevent
a boiler from exploding, didn't notice the simple little statement,
"keep water in it," that was too commonplace to notice. He was looking
for cuts, diagrams, geometrical figures, theories for constructing
engines and boilers and all that sort of thing and didn't find them.
Hence "It is no trick to run an engine."

If this has been your idea of "Rough and Tumble Engineering" forget all
about your theory, and go back and read it over and remember the little
suggestions and don't expect this book to teach you how to build an
engine. We didn't start out to teach you anything of the kind. That is
a business of itself. A good engineer gets better money than the man
who builds them. Read it as if you wanted to know how to run an engine
and not how to build one.

Study the following questions and answers carefully. Don't learn them
like you would a piece of poetry, but study them, see if they are
practical; make yourself thoroughly acquainted with the rule for