geological reasons has found a natural outlet on the surface. We
distinguish two kinds of springs, namely, land or surface springs, and
deep springs. The former furnish water which originally fell as rain
upon a permeable stratum of sand or gravel, underlaid by an impervious
one of either clay or rock. Such water soaks away underground until it
meets some obstacle causing it to crop out on the surface. Such spring
water is not under pressure and therefore cannot again rise. Water
from deep springs is rain water fallen on the surface of a porous
stratum on a high level, and which passes under an impermeable
stratum, and thus, being under pressure, rises again where an opening
is encountered in the impervious stratum; these latter springs are
really artesian in character.

Deep-spring water is less apt to be polluted than water from surface
or land springs, for it has a chance in its flow through the veins of
the earth to become filtered. Land springs always require careful
watching, particularly in inhabited regions, to prevent surface
contamination.

_Not all Spring Water Pure_

It is a popular fallacy that all spring water is absolutely pure and
healthful. The above explanation will be helpful in pointing out how,
in some cases, spring water may be nothing but contaminated ground
water. Land springs in uncultivated and uninhabited regions,
particularly in the mountains, yield a good and pure supply. But it is
always advisable, when tapping a spring for water supply, to study its
probable source, and carefully to inspect its immediate surroundings.
The spring should be protected by constructing a small basin, or
reservoir, and by building a house over this. The basin will also
serve to store the night flow of the spring. Before deciding upon a
supply from a spring, its yield should be ascertained by one of the
well-known gauging methods. Springs are usually lowest in the months
of October and November, though there is some difference in this
respect between land springs and deep springs. The minimum yield of
the spring determines whether it forms a supply to be relied upon at
all times of the year.

If the spring is located higher than the grounds and buildings to be
supplied, a simple gravity supply line may be carried from it, with
pipes of good size, thus avoiding undue friction in the line, and
stoppages. If lower than the house, the water from the spring must be
raised by some pumping method.

All water