of iron three and a half or four inches in diameter,
drawn down to a point, with a furrow cut in the top one and a half
inches deep; a plate, eighteen inches wide and three feet long,
with one end welded into the furrow of the round bar, while the
other is fastened to the beam. The coulter is six inches in width,
and is fastened to the beam at one end, and at the other to the
point of the round bar. The coulter and plate are each
three-fourths of an inch thick, which is the entire width of the
plow above the round iron at the bottom.

"It would require much more team to draw this plow on some soils
than on yours. The strength of team depends entirely on the
character of the subsoil. Cast-iron, with the exception of the
coulter, for an easy soil would be equally good; and from eighteen
to twenty-four inches is sufficiently deep to run the plow. I can
as thoroughly drain an acre of ground in this way as any that can
be found in Seneca County."

From the best information we can gather, it would seem, that on certain
soils with a clay subsoil, the mole plow, as a sort of pioneer
implement, may be very useful. The above account certainly indicates
that on the farm in question it is very cheap, rapid, and effectual in
its operation.

Stephens gives a minute description of the mole plow figured above, in
his Book of the Farm. Its general structure and principle of operation
may be easily understood by what has been already said, and any person
desirous of constructing one may find in that work exact directions.

WEDGE AND SHOULDER DRAINS.

These, like the last-mentioned kind of drains, are mere channels formed
in the subsoil. They have, therefore, the same fault of want of
durability, and are totally unfitted for land under the plow. In forming
_wedge-drains_, the first spit, with the turf attached, is laid on one
side, and the earth removed from the remainder of the trench is laid on
the other. The last spade used is very narrow, and tapers rapidly, so as
to form a narrow wedge-shaped cavity for the bottom of the trench. The
turf first removed is then cut into a wedge, so much larger than the
size of the lower part of the drain, that when rammed into it with the
grassy side undermost, it leaves a vacant space in the bottom six or
eight inches in depth, as in Fig. 14.

The _shoulder-drain_ does not differ very materially from the
wedge-drain.