The Bennington evening banner. (Bennington, Vt.) 19??-1961, 1912-07-13

kind Of clay is not as satisfactory,
however, as the ball clay, as its bind
ing powers are much less. In select
ing clay for road purposes it is always
best to select the stickiest clay avail
able A commG% test is to wet the
thumb and place it against a piece of
clay. If the clay will not stick to the
thumb it is safe to assume that it will
be a poor binder in sand-clay road.
AS the desirable proportions of sand
and clay are such that the particles of
clay barely fill the voids between the
grains of sand, it is well in determin-
ing the quantity of clay to be applied
to a sand road or sand to be applied to
q clay road to know approximately
how much is needed. A simple method
for determining the relative quantity
is to take two glasses of the same size
and fill one with dry sand which it is
proposed to use and the other with wa
ter The water should then be poured
carefully in the glass Of sand and al
lowed TO trickle down through the sand
until it reaches the bottom of the glass.
When the water has been poured into
the glass of sand TO the point Of over
flowing we may assume that the vOids
between the grains of sand have been
filed, and consequently the amount of
water taken from the full glass would
represent the volume Of clay needed to
fill the voids In a volume of sand equal
to that in the other glass. 1t is better
to use little less clay than would ap
pear to be necessary, as the tendency
is to overestimate the amount needed.
Good drainage Is the most essential
feature of the sand-clay road just as it
is Of all other types of road \ sandy
or gravelly soil affords better natural
drainage, and If the sand is present to
an exceptional extent the only provi-
sion necessary for drainage will be to
crown the surface OF the road in the
gravel or macadam roads. If the road
is located through land that is so low
as TO be continually wet ii will be nee
essary in addition to browning the road
TO provide wide bitches on each side
and to raise the roadbed a little higher
than the surrounding country.
After proper drainage has been Sc
cured the roadbed should be crowned
beginning near the source of supply Of
the clay or sand The clay should
then be spread to depth of from six
to eight inches in the center. slipping
Off gradually to a thin layer at the
sides. Upon the clay should be placed
thin covering Of sand. IL the clay
is Of the plastic kind IL will then be
necessary to plow and harrow ii, ad
vantage being taken of rains to puddle
the surface with a disk harrow. Sand
should be gradually added until the
surface Of the road ceases to bali and
cake.
II the clay is placed on sand TO a
depth of six inches a cubic yard OF
clay will cover fifty-four lineal feet;
consequently a sixteen foot road treat
ed in this manner would require one
cubic yard of clay for each three feet
Of length. A mile OF sixteen foot
road would therefore require LEO
cubic yards of clay.
If the clay subsoil Is to be treated
with sand II should be plowed and
narrowed TO a depth Of about four
inches. On this prepared subsurface
should be placed from six to eight
inches Of clean sand. spread thickest
ut the center and sloping TO the sides
I'm much the same manner as the clay
is applied to a sand road. These ma
terials should then be mixed dry in
stead of the wet mixing, which is
preferable when clay is applied to
sand This IS preferable because the
clay can be better pulverlzed when in
dry state. After dry mixing the road
should be puddled following the first
heavy rain. When the materials are
thoroughly mixed and puddled a road