y at something
else, and can't see anything for grease and dirt. When he starts up, ten
to one the wrist pin heats and he stops and loosens it up and then it
knocks. Now if he had picked up a rag instead of a wrench, he would not
have hit that key but he would have run his hand over it and if he had
found it all right, he would have let it alone, and would have gone over
the balance of the engine and when he started up again his engine would
have looked better for the wiping it got and would have run just as well
as before he stopped it. Now you will understand why a good engineer
wears out more rags than wrenches, while a poor one wears out more
wrenches than rags. Never bother an engine until it bothers you. If
you do, you will make lots of grief for yourself.

I have mentioned the bad habits of a poor engineer so that you may avoid
them. If you carefully avoid all the bad habits connected with the
running of an engine, you will be certain to fall into good habits and
will become a good engineer.

TINKERING ENGINEERS

After carelessness, meddling with an engine comes next in the list of
bad habits. The tinkering engineer never knows whether his engine is in
good shape or not, and the chances are that if he should get it in good
shape he would not know enough to let it alone. If anything does
actually get wrong with your engine, do not be afraid to take hold of
it, for something must be done, and you are the one to do it, but before
you do anything be certain that you know what is wrong. For instance,
should the valve become disarranged on the valve stem or in any other
way, do not try to remedy the trouble by changing the eccentric, or if
the eccentric slips do not go to the valve to mend the trouble. I am
well aware that among young engineers the impression prevails that a
valve is a wonderful piece of mechanism liable to kick out of place and
play smash generally. Now let me tell you right here that a valve (I
mean the ordinary slide valve, such as is used on traction and portable
engines), is one of the simplest parts of an engine, and you are not to
lose any sleep about it, so be patient until I am ready to introduce you
to this part of your work. You have a perfect right to know what is
wrong with the engine. The trouble may not be so serious and it is
evident to you that the engine is not running just as nicely as it
should. Now, if your engine runs irregularly, that is if it runs up to
a higher