The Clarksburg telegram. [volume] (Clarksburg, W. Va.) 1874-1926, 1912-07-11

- GOOGhb1 oOAhE NhhNL Ill 1tOADs
pits, which are frequently termed gla-
cial grayels on account OF their direct
or Indirect association with Ice action,
are quite widely distributed, and these
have been and may be used to q
greater or less extent in road improve
ment.
During recent geological history of
the continent the Atlantic and gulf
borders have been submerged ut inter
walls. The ocean has advanced inland
a, number of times. During each of
these periods OF continental submer-
gence the harder rock remanepts along
the inner margins of the oceans nd
vance have been rounded, worn down,
deposited and redeposlted with vary
Ing proportions of sands and loans
and clays. thus forming beds Of grav-
Ell, which are today available for road
buli0iAg purposes.
GFavel roads and macadam roads
alike have often received sweeping con-
formations as unsatisfactory when the
cause, of failure was poor construction
lind not the character Of the material
used The need of care In grading and
drainage in the construction of macad.
am roads is being quite generally rec
ognized. but unfortunately many anna
teur road builders seem to think that
gravel roads may be constructed by
simply piling gravel on the surface and
iepving It to be packed by the passing
traffic. In point of fact, the grading
and drainage and other details In con-
riection with the construction Of
gravel road should be done with as
much care and thoroughness as in the
cnse Of q macadam road Moreover. In
the one case us in the other specifica.
lions must be adapted 10 varying local
conditions. OF course. the gravel itself
must be selected with care. That which
contains sufficient quantity Of bind.
Ing material so that It stands as YER
teal wall when It is being excavated
is generally the best, for the reason
that this same binding material will
re;cement the gravel when used for
road building.
There are three important qualities
which should be possessed by road
building gravcl-hardness, toughness
and cementing or binding power. OF
these three qualities the last Is the
most important. This binding quality
Is due In part to the presence of oxide
of iron, lime or ferrugineous clay and
in part to the angular shape and size
Of the pebbles composing the gravel.
Blue gravel Is universally conceded to
be the best for road construction, be.
cause 1t is usually derived from trap
cock, AS the pebbles composing the
gravel retain the characteristics which
they formerly possessed as part OF
the larger rock itself. It follows that as
trap rock Is considered an excellent
mateFinl for road building, trap rock
gravel should occupy the same relative
rank among the gravels. Limestone Is.
generally speaking, soft rock, and
consequently limestone gravel, which.
Is quite rare, win usually be found
soft and will wear rapidly. Quartz
possesses practically no binding power,
although 1t is very hard. Therefore
gravel which contains an exception.
allylarge percentage of quartz will not
prove successful. as It will fail to con.
solidate unless 1t contains binding ma.
terial, or unless good binder is added.
In order that the material may bind
readily the pebbles should be angular
and should vary in size so TINT the
mailer fragments may all the voids
q -