inage is not all that is necessary. Common side
drains catch surface water and surface water only. Isaac Potter says:

"Many miles of road are on low, flat lands and on springy
soils, and thousands of miles of prairie roads are, for many
weeks in the year, laid on a wet subsoil. In all such cases,
and, indeed, in every case where the nature of the ground is
not such as to insure quick drainage, the road may be vastly
benefited by under drainage. An under drain clears the soil
of surplus water, dries it, warms it, and makes impossible
the formation of deep, heavy, frozen crusts, which are found
in every undrained road when the severe winter weather
follows the heavy fall rains. This crust causes nine-tenths
of the difficulties of travel in the time of sudden or
long-continued thaws.

"Roads constructed over wet undrained lands are always
difficult to manage and expensive to maintain, and they are
liable to be broken up in wet weather or after frosts. It
will be much cheaper in the long run to go to the expense
of making the drainage of the subjacent soil and
substructure as perfect as possible. There is scarcely an
earth road in the United States which cannot be so improved
by surface or subdrainage as to yield benefits to the
farmers a hundred times greater in value than the cost of
the drains themselves.

"Under drains are not expensive. On the contrary, they are
cheap and easily made, and if made in a substantial way and
according to the rules of common sense a good under drain
will last for ages. Use the best tools and materials you can
get; employ them as well as you know how, and wait results
with a clear conscience. Slim fagots of wood bound together
and laid lengthwise at the bottom of a carefully graded
drain ditch will answer fairly well if stone or drain tile
cannot be had, and will be of infinite benefit to a dirt
road laid on springy soils."

Subdrains should be carefully graded with a level at the bottom to a
depth of about four feet, and should have a continuous fall throughout
their entire length of at least six inches for each one hundred feet in
length. If tile drains cannot be had, large, flat stones may be
carefully placed so as to form a clear, open passage at the bottom for
the flow of the water. The ditc