ols and have someone
place a small sheaf of wheat or oat straw under the firebox or under
waist of boiler if open firebox, and set fire to it. The expansive
force of the water caused by the heat from the burning straw will
produce pressure desired. You should know, however, that your safety is
in perfect order. When the water begins to escape at the safety valve,
you can readily see if you have expanded your flues sufficiently to keep
them from leaking.

This makes a very nice and steady pressure, and although the pressure is
caused by heat, it is a cold water pressure, as the water is not heated
beyond one or two degrees. This mode of testing, however, cannot be
applied in very cold weather, as water has no expansive force five
degrees above or five degrees below the freezing point.

These tests, however, are only for the purpose of trying your flues and
are not intended to ascertain the efficiency or strength of your boiler.
When this is required, I would advise you to get an expert to do it, as
the best test for this is the hammer test, and only an expert should
attempt it.

PART SIX ________

Any young engineer who will make use of what he has read will never get
his engine into much trouble. Manufacturers of farm engines to-day make
a specialty of this class of goods, as they endeavor to build them as
simple and of as few parts as possible. They do this well knowing that,
as a rule, they must be run by men who cannot take a course in practical
engineering. If each one of the many thousands of engines that are
turned out every year had to have a practical engineer to run it, it
would be better to be an engineer than to own the engine; and
manufacturers knowing this, they therefore make their engines as simple
and with as little liability to get out of order as possible. The
simplest form of an engine, however, requires of the operator a certain
amount of brains and a willingness to do that which he knows should be
done; and if you will follow the instructions you have already received,
you can run your engine as successfully as any one can wish as long as
your engine is in order, and, as I have just stated, it is not liable to
get out of order, except from constant wear, and this wear will appear
in the boxes, journals and valve. The brasses on wrist pin and
cross-head will probably require your first and most careful attention,
and of these two the wrist or crank box will require the most; and what