McNairy County independent. (Selmer, McNairy County, Tenn.) 1902-1969, 1914-01-23
he proportion of clay needed.

clay can best be determined, however
as the work progresses, as some clay
will contain more sand than others
In fact, clays are very frequently
found which already contain about The
right proportion of sand.
If the road to be treated is sandy
the surface is first leveled off and
crowned with a road machine, the
crown being about J inch to the foot
from the center to the sides. The
clay is then dumped on the surface
and carefully spread, so that it will
be from 6 to 8 inches in depth at the
center, and gradually decreasing in
depth towards the sides. A layer of
clean sand is then usually added,
which is thoroughly mixed with the
clay, either by traffic or by means of
plows and disk or tooth harrows.
The best results have been obtained
by thoroughly mixing or pudding the
material when wet. For this reason,
it is desirable that the mixing be
done in wet weather. The mixing
can be left to the traffic after the
materials have been properly placed,
but this involves whole winter and
spring of bad road. and even then the
mixing is not always satisfactory. In
all cases, it is advisable to dress the
road with road machine or split-log
drag after the materials have been
thoroughly mixed, and to give it a
crown of not more than / inch nor
less than / inch to the foot from the
center to the sides. A light coating
of sand may then be added. The use
of the road machine or drag should
be continued at frequent intervals
until the surface is smooth and firm.
If the road to be treated is CON-
posed of clay, it should first be
brought to a rough grade with road
machine. The surface should then
be plowed and thoroughly pulverized
by narrowing to depth of about A
inches after which it is given crown
or slope of about J inch to the foot
from the center to the sides. It is
then covered with 6 to 8 inches of
clean, sharp sand, which is spread
thicker in the center than at, the
sides. The materials should then be
mixed with plows and harrows while
they are comparatively dry, after
which they are finally puddled with a
harrow during wet weather. If clay
works to the surface and the road
becomes sticky, more sand should be
added.
The roadsis then shaped, crowned,
and ditched in the usual manner with
road machine. This should be done
when the surface is soft, yet stiff
enough to pack well under the roller
OF the traffic. Wide but shallow
bitches should be provided on both
sides of the road, and culverts or
crossdrains should be placed wherever
water flows across the road, for it is
exceedingly important that the Sand
on clay roads be we'll drained.
After the clay on sand, or the sand
on clay, road is completed, it should
be carefully maintained until the sur
face becomes firm and smooth. The
construction Of this type of road is
| y no means quick operation. If
soft, sticky places appear, more sand
should be added, and il loose, sandy
places are found, more clay is needed.
1t is just as important to attend to
these small details rs to any other
part of the work, for if they are neg
lected the road is liable to fail.
1t requires approximately | cubic
yard of clay to surface u running
yards of road II feet in width, or
about ll75 cubic yards to the mile.
From I to ! cubic yard will make a
load for two horses on a dry clay road
The cost of the road will therefore
depend largely upon the distance the
material is hauled, the average being
from $500 to $1,000 per mile. A
road built under the direction of the
Office of Public Roads at Gainesville,
Florida, one mile long, IA #. wide,
and having 9 inches of sand-clay sur
face. cost 1881 per mile, or ten cents
per square yard. Another sand-clay
road built by the Office at Tallahassee,
Florida, l6 fit. wide, 7 inches thick,
cost $470 per mile, or about five
cents per square mile.