The Dawson journal. (Dawson, Ga.) 1878-18??, 1884-08-14
Artesian Wells.


wells is agitating the public mind it
may be well enough to enquire as to
the principle upon which water rises
from such great depth and is fore
cd with so much volume above the
surface of the earth. There prevails
current opinion that the water,
rising somewhere in the mountains,
at high elevation. and running in q
channel far below the surface, rises to
the level of its source wherever an
opening is made into it from above.
Ii it were possible to obstrcct such
current by the insertion of an iron
pipe this would be the result, other
wise the current must pass around
the pipe and continue to flow on in
its bed. Az we cannot suppose a
pipe of 81 few inches in diameter to
dun Up stream of amy size, this
theory must be abandoned.
1t is well known that the geologi-
cal structure of the earth's surface
consists of different layers or strata,
lying one above the other. All Of
these contain more or less water.
They part with their water in pro-
portion as they are closely or loose
ly compacted-rhalk, which is com
posed Of very fine PARTICLES, while
holding proportonably as much wa
ter as sand, does not part with it so
readily, and, because of this, wells
having chalk bottom yield very
little water Sand contains about
one-th;rl Of its bu.k in water and
readily parts with nearly the whole
of it where regularly pumped or
drawn out. Our common wells are
applied, not SO much from under
ground currents as is generally sup
posed, but from water, which, having
fallen upon the surface above, is
filtered through the earth and held
in the sandstone strata below. The
d fferent strata CT the earth'8 sur
flce lie at irregular angles. tt often
occurs, that beginning at the sur
face at one point they run down Oh
ljquely to consi lerabIe depth, and
rising to the surface again at a dis
tant point take the form of a basin,
with the lowest point several hun
dred feet below the surface. To
employ terms in common use, these
strata consist of clay, chalk, mari,
rock, sand, etc., in alternate layers.
All of these are comparatively i'm
pervious to water except sand, which
receives it readily and parts with it
freely. When the sand strata crop
oIt at the surface the rain-water fall.
ling upon them is rapidly absorbed
and flows down into the basin be-
meath. If the stratum of sand is
confined between two impervious
beds, such as rock above ana clay
below, : IS evident that the accum.
ulation of water in the sand from
above will eventually bring about a
very great pressure upon the water
Ia the bottom Of the basin. II now
q perforation is made through the
SIND at the bottom 81 the basin, the
water will rise through the opening
to height depending upon the pres
sure of the water which has accumu-
lated in the confined sloping space
between the two Impervious beds.
IF the diameter Of the basins be
great, that is, if there be a consider
able distance between the points at
which the sand stratum crops out at
the surface, then the volume Of water
contained being great, the pressure
will be proportionably great, and, as
a rule, the depth of the well will be
in proportion to the diameter of the
basin. Again, the height to which
the water is forced above the ground
will be in proportion to the altitude
of the locality Of the well as COM
pared to the altitude where the edges
Of the sand stratum appears at the
surface. The localities of the well
being lower, the water will rise high
er. If the we'll strikes the lowest
point of the basin then, because of
the pressure from both sides upon
it, the force will be greater. II it
should strike one of the sloping
sides the pressure, being in one di-
rection only, will be proportionably
less. Ii the sandstone stratum does
not slope toward the surface or if il
is not confined between two imper.
} yious beds it is impossible to succeed
with an artesian well. Artesian
water is, therefore, not water from
mountain springs, but nothing more
! than surfaca wafar fltarn1 throrob