acquainted with the principles of hydraulics. It is thus seen that the
ancient Romans spared no pains to obtain a supply of pure water for their
cities, and I think it is high time that we followed their example, and
went to the trouble and expense of obtaining drinking water from
unimpeachable sources, instead of, as is too often the case, taking
water which we know perfectly well has been polluted, and then attempting
to purify it for domestic purposes.

* * * * *




STEAM ENGINE ECONOMY.

By Chief Engineer JOHN LOWE, U.S. Navy.


The purpose of this article is to point out an easy method whereby any
intelligent engineer can determine the point at which it is most
economical to cut off the admission of steam into his cylinder.

In the attack upon such a problem, it is useful to employ all the senses
which can be brought to bear upon it; for this purpose, diagrams will be
used, in order that the sense of sight may assist the brain in forming
its conclusions.

[Illustration: STEAM ENGINE ECONOMY.--BY JOHN LOWE, CHIEF ENGINEER
U.S.N.]