The Portland daily press., 1892-05-21
nlRI ROADS.
How They IIay BE Treated So as to Make
Them PassebIe.


found in the line of the roadway. They
are so common as to be almost our only
roads outside of town and city limits,
and will for many years be used largely
in country districts, and especially on
the lines OF crossroads which connect
the main highways. Dirt roads, at their
best, are greatly inferior to macadam
and telford roads in every essential of a
good highway; in durability, cost of
maintenance, drainage, tractive quail
ties, and in many locations in point of
economy also. But the dirt road is here
and the public hand must be directed to
its treatment. The first and most i'm
portant thing necessary for the main
tenance of dirt road may be stated in
a single word-drainage 1t is the one
thing that can neither be dispensed with
nor neglected Most dirt is soluble and
is easily displaced under the softening
influence of rain, and this process is
fastened in the dirt road by the passing
of heavy wagons over the wet surface.
On every mile of roadway within the
United States there falls each year an
average of 81, 900 tons of water-a heavy,
limpid fluid, always directing itself to
the nearest outlet and seeking the lowest
level. Water is hard to confine and
easy to release, and yet through sheer
neglect Of the simplest principles of
drainage water is the most active de-
stroyer of our country roads.
In providing for the drainage of a dirt
road we should first consider the mate
rial of which the roadway is composed.
Ii heavy, viscous clay predominates
the ordinary side bitches should be of
good depth, and will even then, in many
cases, be inadequate for thorough drain
age without the addition of a center
drain running midway between and par
allel with the side bitches. The center
drain should of course be filed with
loose, irregular powders, cobblestones,
broken bricks or similar filling, covering
a line of tiles or fascines at the bottom,
and should be connected with the side
bitches by cross drains carrying the water
outward from the center drain at proper
intervals along the length of the road
way. Y Center drains, though
often greatly needed for the improve
ment OF country roads, are not in COM
mon use. They add somewhat to the
cost of the roadway, but in most cases
considerably more to its value, and
should be employed in all situations
where sand or gravel cannot be had to
relieve the heaviness and water holding
properties Of the clay. If gravel, sand
or other porous material can be conven-
iently or cheaply obtained the center and
cross drains may often be dispensed with
by mixing the gravel or sand in plentiful
quantities with the clay roadway, SO as
to insure as nearly as possible porous
and self draining surface layer, which
should not be less than ten inches in
depth and should be laid on the rounded
or sloped subsoil SO as to insure easy
drainage into the side bitches.
In locations where the prevailing ma
terial is of loose, sandy nature, the diff
ficulties of drainage are more easily
overcome, and side bitches, if found
necessary at all, may be made of rnoder-
ate depth and left open without incur
ring the risks and dangers of travel that
prevail where the deeper open bitches
are used for draining heavier soils. But
on the other hand, the light and shifting
nature of sandy road material destroys
its value as surface layer for an earth
roadway, and its efficiency in this re-
spect is most easily remedied by the ad-
dition of stronger and more tenacious
substance, such as stiff clay. When
mixed with sand in proper proportions
(which in each case depend upon the ma
ture of the clay and sand used, and
which can best be determined by expert
ment), this composition affords many
advantages which make it superior to a
roadway composed of either sand or
clay when used alone. The sand serves
to quicken the drainage and to destroy
the sticky, tenacious qualities of the
clay, while the clay supplies the quality
of cohesion in the substance of the road
surface, counteracting the shifting quail
ties of the sand and making the road
way more easily packed and rolled and
more likely to retain its proper grade
and slope.
Every day it is becoming more firmly
established that good road roller is the
most valuable piece of machinery en-
ployed in the roadmaker's art; and in
deed, without it, neither can the founda-
ton or subsoil of the roadway be made
uniformly hard and reliable, nor the
surface layer be given that uniform COM
pactness and solidity which give excel
lence to the road and insure perpetual
economy in the cost of maintenance and
repairs To one who has seen a heavy
road roller used in compacting the soil
Of a new roadway these facts will be
very evident. If a length of 1 900 yards
in an ordinary earth road be cut to an
exact and uniform grade one foot below
the original surface of the road, it will
be found in most cases that the new sur
face thus exposed will present an ap-
pearance which, to the ordinary observ-
or, is of a uniform material and even
hardness from end to end; but the pas
sage of roller weighing from ten to tif-
teen tons over this new surface will soon
disclose defects and soft spots located at
irregular intervals throughout the length