s for all the water that could be poured
into them. In the Report of the Tioga County Agricultural Society for
1857, it is said in the _Country Gentleman_, that instances are given,
where swamps were drained through the clay bottom into the underlying
gravelly soil, by digging wells and filling them with stones.

In Fig. 7, at page 82, is shown a "fault" in the stratification of the
earth; which faults, it is said, so completely carry off water, that
wells cannot be sunk so as to reach it.

Mr. Denton says that in several parts of England, advantage is taken of
the natural drainage existing beneath wet clay soils, by concentrating
the drains to holes, called "swallow-holes." He says this practice is
open to the objection that those holes do not always absorb the water
with sufficient rapidity, and so render the drainage for a time,
inoperative.

These wells are liable, too, to be obstructed in their operation by
their bottoms being puddled with the clay carried into them by the
water, and so becoming impervious. This point would require occasional
attention, and the removal of such deposits.

This principle of drainage was alluded to at the American Institute,
February 14, 1859, by Professor Nash. He states, that there are large
tracts of land having clay soil, with sand or gravel beneath the clay,
which yet need drainage, and suggests that this may be effected by
merely boring frequent holes, and filling them with pebbles, without
ditches. In all such soils, if the mode suggested prove insufficient,
large wells of proper depth, stoned up, or otherwise protected, might
obviously serve as cheap and convenient outlets for a regular system of
pipe or stone drains.

Mr. Bergen, at the same meeting, stated that such clayey soil, based on
gravel, was the character of much of the land on Long Island; and we
cannot doubt that on the prairies of the West, where the wells are
frequently of great depth to obtain water for use, wells or
swallow-holes to receive it, may often be found useful. Whenever the
water-line is twenty or thirty feet below the surface, it is certain
that it will require a large amount of water poured in at the surface of
a well to keep it filled for any considerable length of time. The same
principle that forces water into wells, that is, pressure from a higher
source, will allow its passage out when admitted at the top.

We close this chapter with a letter from Mr. Denton. The extract
referred to, has