found underground owes its origin to the rainfall. If
concealed water is returned to the surface by _natural processes_ it
is called spring water, but if recovered by _artificial means_ it is
called well water.

_Different Kinds of Wells_

There are numerous kinds of wells, distinguished from one another by
their mode of construction, by their depth from the surface, by the
fact of their piercing an impervious stratum or merely tapping the
first underground sheet of water, and by the height to which the water
in them rises or flows. Thus we have shallow and deep wells,
horizontal wells or infiltration galleries, open or dug wells, tube
wells, non-flowing and flowing wells, bored, drilled, and driven
wells, tile-lined and brick-lined wells, and combination
dug-and-tubular wells.

When it is desired to provide a water supply by means of wells some
knowledge of the geology of the region, of the character of the strata
and of their direction and dip, will be very useful. In the case of
deep wells, it is really essential. By making inquiries as to similar
well operations in the neighborhood, one may gain some useful
information, and thus, to some extent, avoid guesswork. When one must
drill or bore through rock for a very deep well, which necessarily is
expensive, much money, often uselessly spent, may be saved by
consulting the reports of the State geologist, or the publications of
the United States Geological Survey, or by engaging the services of an
expert hydrogeologist.

"_Water Finders_"

It used to be a common practice to send for so-called "water finders,"
who being usually shrewd observers would locate by the aid of a hazel
twig the exact spot where water could be found. In searching for water
one sometimes runs across these men even to-day. The superstitious
faith in the power of the forked twig or branch from the hazelnut bush
to indicate by its twisting or turning the presence of underground
water was at one time widespread, but only the very slightest
foundation of fact exists for the belief in such supernatural powers.

In Europe, attention has again, during the past years, been called to
this "method" of finding water, and it has even received the
indorsement of a very high German authority in hydraulic engineering,
a man well up in years, with a very wide practical experience, and the
author of the most up-to-date hand-book on "Water Supply," but men of
science have not failed to contradict his st