level with a brook which runs through this clay soil. I filled a
one hundred-pound nail-keg with clay taken from the same place. It
was so wet, that by shaking, it came to a level, and water rose to
the top of the clay. I had made holes in the bottom of the keg, and
set it up on blocks. After twenty-four hours I came almost to the
conclusion Mr. Johnston did, that water would not pass through this
clay. This trial was during the hot, dry weather last Summer. After
some ten or twelve days the clay appeared to be dry. I then made a
basin-like excavation in the top of the clay, and put water in, and
the water disappeared rather slowly. I filled the basin with water
frequently, and the oftener I filled it, the more readily it passed
off. I left it for more than a week, when we had a heavy shower.
After the shower I examined the keg, and not a drop of water was to
be seen. I then took a chisel and cut a hole six inches down. I
took out a piece like the one I dried in the house, and laid that
up till it was perfectly dry. There was a plain difference between
the appearance of the two pieces. The texture, I should say, was
quite different. That through which the water had passed, after it
had been dried, was more open and porous. It did not possess so
much of the blue cast. In less than one hour after the rain fell,
the clay taken six inches from the top of the keg would crumble by
rubbing in the hand."

When we observe the effect of heat in opening clays to water by
cracking, and the effect of the water itself, aided, as it doubtless is,
by the action of the air, in rendering the soil permeable, we hardly
need feel discouraged if the question rested entirely on this evidence;
but when we consider that thousands upon thousands of acres of the
stiffest clays have been, in England and Scotland, rescued from utter
barrenness by drainage, and made to yield the largest crops, we should
regard the question of practicability as settled. The only question left
for decision is whether, under all the circumstances of each
particular case, the operation of draining our clay lands will be
expedient--whether their increased value will pay the expense. It is
often objected to deep drains in clays, that it is so far down to the
drains that the water cannot readily pass through so large a mass. If
we think merely of a drop of rain fal