“_Among the first things a practical engineer should know, and among
the last things he will, after becoming such, forget, is that in
handling water within pipes he has a fluid which, while it is flexible
to the greatest extent and is susceptible of the influence of power,
or force, of greater or less intensity, and while it may be drawn from
below and raised to the heights above, can be turned to the right or
to the left at will, and while, with a seeming docility which is as
flattering as it is deceptive, it bends itself to the will of the
engineer, still there are some things it will not do, and which all the
complicated appliances of the engineer have as yet failed to compel it
to do. When inclosed within chambers and pipes, to an extent that fills
them, it will not permit the introduction of an added atom without
bursting its bounds. While inclosed within long lines of pipes it will
not suddenly start into motion, or when in motion suddenly come to a
rest, without shocks or strains more or less disastrous; and so, while
it seems to be handled with the greatest ease, it is only in the manner
it chooses to go, and all mechanical appliances not designed with
reference to following these imperative laws are sure to meet trouble,
if not disaster. In other words, when an unyielding force meets an
unyielding resistance, their coming together means a shock to all
about._”
INTRODUCTORY
CONSIDERATIONS
“_Whenever a full mind meets an empty one, it is a call to teach, not
to scoff._”—ANON.
[Illustration: ORIFICES OF PIPES, ETC., SYMBOLICAL OF IRRIGATION.]
“_He who sedulously attends, pointedly asks, calmly speaks, coolly
answers and ceases when he has no more to say, is in possession of some
of the best requisites of man._”—LEVATER.