Petroleum is not a bad thing in water where sulphate of lime prevails;
but you should use only the refined, as crude oil sometimes helps to
form a very injurious scale. Carbonate of soda and corn-starch have been
recommended as a scale preventative, and I am inclined to think they are
as good as anything, but as we are out in the country most of the time I
can tell you of a simple little thing that will answer the same purpose,
and can usually be had with little trouble. Every Monday morning just
dump a hatful of potatoes into your boiler, and Saturday night wash the
boiler out, as I have already suggested, and when the fall's run is over
there will not be much scale in the boiler.


CLEAN FLUES.

We have been urging you to keep your boiler clean. Now, to get the best
results from your fuel, it will also be necessary to keep your flues
clean; as soot and ashes are non-conductors of heat, you will find it
very difficult to get up steam with a coating of soot in your tubes.
Most factories furnish with each engine a flue cleaner and rod. This
cleaner should be made to fit the tubes snug, and should be forced
through each separate tube every morning before building a fire. Some
engineers never touch their flues with a cleaner, but when they choke
the exhaust sufficiently to create such a draught as to clean the flues,
they are working the engine at a great disadvantage, besides being much
more liable to pull the fire out at the top of smokestack. If it were
not necessary to create draught by reducing your exhaust nozzle, your
engine would run much nicer and be much more powerful if your nozzle was
not reduced at all. However, you must reduce it sufficiently to give
draught, but don't impair the power by making the engine clean its own