The Iola register., 1890-11-07
ROAD-MAKING.
Some Practical Hints on n Very Impor-
tant Suhiect.


tant Subject.
The following extracts from The En-
gineering and Building Records prize
essay on road-making (by S. c. Thomp.
son, New York;, contain many yalu-
able facts:
A man can walk up slope of 100 in
100, and horse or mule can ascend an
incline of 100 in It's, and it has been
found by experiment that horse pull
ing his maximum load on level can
pull but four-fifths rs much il the slope
is made 1 in so, and this gradually
lessons until with slope Of in 10 he
can draw but one-fourth as much as his
level load. The maximum grade es-
tablished by the French Government
board of engineers is in 20. The Holy
head road in Wales uses 1 in so as
maximum, except in two cases. The
road over the Simplon Pass averages
1:22 on Italian side, and to II on Swiss
side. with one case of to 12, and in this
State several turnpike roads are limited
by law to in IL. In laying out road,
with regard to grades, have a continu-
Gus inclination in one direction and do
not allow any counter grades, for, in as
cending, each foot descended on coun-
ter grade means just so much more rise
to be overcome.
Where theroadway is too wide it usual
ly results in no part being kept in good
repair, while if it was narrowed the
whole could be kept in frst-class condi-
ton at less expense, and a well-kept
road of even twenty feet width is far
preferable to road but half maintained
of double the width. in laying cut il
may be advisable to take a strip con-
siderably wider than the intended road
bed, so as to provide for possible con-
tingencies in the future when the land
becomes more valuable. Lay out sufii-
ciently wide, but build only so much as
can be kept in thorough repair. The
essential requirements of good road
bed are that it shall be practically un-
yielding-smooth on the surface, and
impervious to water-and without these
requirements there can be but little
durability.
For surface draining, bitches should
be provided along each side of the road
having sufficient fall to promptly carry
away any water that reaches them.
Where it becomes necessary to carry the
water across the roadway, culverts
should be provided. All drains should
have continuous fall throughout their
entire length. and the size will depend
upon the inclination and the amount of
water they are expected to, carry. In
portions of the country where gravel is
easily obtained very satisfactory road
can be made by making the surface for
a greater,or less depth of gravel
Prepare the foundation so as to allow
for prompt drainage, and shape as the
finished road is intended to be; make
the side of the road planes, and not
curves, and then roll thoroughly to get
solid foundation. Put on a layer of
gravel from six inches to eight inches
in thickness, sprinkle thoroughly and
roll until very compact and firm. Next
spread another layer from four to six
inches of gravel, and sprinkle and roll
until the desired hardness and smooth
ness are obtained. If the gravel has no
binding material in it, sufficient
amount may be incorporated in the last
layer to cause it to take good bond.
Where it is possible to get blue gravel
or hard pan and clean bank gravel, the
two can be so mixed as to give surface
almost like concrete in hardness When
the two are used together two-horse
grooved roller for the first layer will be
found very effective, and the material
should be quite wet while rolling. The
surface can then be finished with
steam roller, or with a smooth roller
sufficiently loaded to give the requisite
weight. In completing the surface of
gravel or other road, where rolling is
sequired, the weight of the roller should
he as much per inch as the weight per
inch on the tire of the heaviest vehicle
likely to pass over it. For ordinary
traffic a very durable and economical
surface can be thus produced.