with either brick, stone, or
tile pipe, cemented in a water-tight manner to a depth of at least
twenty feet from the surface, so that no water can enter except from
the bottom, or at the sides near the bottom.

Raise the surface at the top of the well above the grade; arrange it
so as to slope away on all sides from the well; cover it with a
flagstone, and cement the same to prevent foreign matters from
dropping into the well; make sure that no surface water can pass
directly into the well; make some provision to carry away waste water
and drippings from the well.

Shallow wells made by driving iron tubes with well points into the
subsoil water are preferable to dug wells. Use a draw-pump in
preference to draw buckets.

When a well is sunk through an impervious stratum to tap the larger
supply of water in the deeper strata, we obtain a "deep well." Water
so secured is usually of great purity, for the impurities have been
filtered and strained out by the passage of the water through the
soil. Moreover, the nature of the construction of deep wells is such
that they are more efficiently protected against contamination, the
sides being made impervious by an iron-pipe casing. In some rare
cases, even deep wells show pollution due to careless jointing of the
lining, or water follows the outside of the well casing until it
reaches the deeper water sheet. Deep wells usually yield more water
than shallow driven wells, and the supply increases perceptibly when
the water level in the well is lowered by pumping. While surface
wells draw upon the rainfall percolating in their immediate vicinity,
deep wells are supplied by the rainfall from more remote districts.
Deep wells are either non-flowing or flowing wells. When the
hydrostatic pressure under which the water stands is sufficient to
make it flow freely out on the surface or at the mouth of the well, we
have a flowing, or true artesian well.

_Character of Water From Deep Wells_

Water from deep wells is of a cool and even temperature. It is usually
very pure, but in some cases made hard by mineral salts in the water.
Sulphur is also at times present, and some wells on the southern
Atlantic coast yield water impregnated with sulphur gases, which,
however, readily pass off, leaving the water in good condition for all
uses. In many cases the water has a taste of iron. No general rule can
be quoted as to the exact amount of water which any given well will
yield, for this