nothing will be left out that would be of practical value to you. You
will not find any geometrical figures made up of circles, curves,
angles, letters and figures in a vain effort to make you understand the
principle of an eccentric. While it is all very nice to know these
things, it is not necessary, and the putting of them in this book would
defeat the very object for which it was intended. Be content with being
a good, practical, everyday engineer, and all these things will come in
time.


INTRODUCTORY ________


If you have not read the preface on the preceding pages, turn back and
read it. You will see that we have stated there that we will use no
scientific terms, but plain every day talk. It is presumed by us that
there will be more young men, wishing to become good engineers, read
this work than old engineers. We will, therefore, be all the more plain
and say as little as possible that will tend to confuse the learner, and
what we do say will be said in the same language that we would use if we
were in the field, instructing you how to handle your engine. So if the
more experienced engineer thinks we might have gone further in some
certain points, he will please remember that by so doing we might
confuse the less experienced, and thereby cover up the very point we
tried to make. And yet it is not to be supposed that we will endeavor to
make an engineer out of a man who never saw an engine. It is, therefore,
not necessary to tell the learner how an engine is made or what it looks
like. We are not trying to teach you how to build an engine, but rather
how to handle one after it is built; how to know when it is in proper
shape and how to let it alone when it is in shape. We will suppose that