Middletown transcript. [volume] (Middletown, Del.) 1868-current, 1909-09-18
THE TOP SOIL ROAD
Details Of a Method Which Originated
m Clark County. Ga.

4 lm LARK C0unty, va.
A new method Of road construction
which was recently evolved in ClarI
county. Ga. is called the top soil methol
because il consists Of building the road on
Of the surface soil from the adjacent fields
In some repects it is like the sand-cIa,
method while in others it is similar to th,
gravel roads. So far as the writer il
aware Clark county, Ga, enjoys the dis
tinction OF having originated this method
The details we're worked out BY Professor
G. M. Strain Of Georgia university and
Clark county's commissioner Of deeds.
The success Of this method depends
largely upon the soil used. Just any soil
will not do. It must have enough sand
or gravel in il TO resist the action OF the
traffic aud weather aud enough clay to
bind the particles together. 1t is well
known that, although clay has q high
cementing value, it will not make good
road II used alone on account of the fact
that when it is wet it absorbs moisture
and softens. It is also well known that
round, water worn gravel or sand which
is clear and free from clay will not pro-
duce satisfactory road surface because
neither will bind, but if clay, gravel and
sand are mixed together in certain pro.
portions they have been found to produce
a surface which will be both hard and
smooth the year round.
II these materials can be found already
mixed the trouble and expense OF mixing
can be avoided. It is common practice
throughout tue United States to use bank
gravel for road surfacing which has a
little clay in it, but Clark county is the
first, / believe, to skin the top soil from
the Rdjaceut fields and use it for this pur.
pose. 1t was observed in CIarks county
that where the top soil consisted of
mixture of sand, gravel and clay the
sand and gravel had been drawn toward
the surface aud incorporated with the
clay during cultivation.
The road is located and graded in the
same manner as for gravel or macadam.
Tile foundation is then shaped with
road machine and slightly crowned in
the center, after which a. layer of suitable
sop soil is spread to width of about six.
teen feet and depth OF about ten inches
in the center and three or four inches ct
the sides. The next step is to open up
the side bitches with road machine.
The earth from the bitches is thrown up
against the bed OF top soil as a shoulder.
The road machine is then used to level
of the surface aud to give it the proper
slope from the center to the side bitches.
The road is now thrown OPEN to traffic
and soon packs down into a hard, dry
surface. If rainy weather occurs during
the spreading Of the material or soon
after, so much the better. Wet weather
and heavy traffic assist In the mixing and
pudding process. After this process has
continued until the surface soil is thor.
oughly mixed the road is dressed and re-
shaped with light two horse grader.
This treatment is continued until the sur
face is we'll hardened and all soft or un-
even spots are removed.
To get the best top soil along any Ear.
ticular road hand samples are taken and
examined before the work is begun.
Samples Of uniform size are selected and
The percentage of gravel, sand and clay
by washing out the clay and
sitting out the sand. The sample which
appears to have about the right proper
lion of sand gravel and clay is selected.
From 10 to25 per cent. of clay appears to
be sufficient for binding material.
Aside from the grading, these top soil
roads cost from $3.50 to $500 per mile.