The citizen. (Honesdale, Pa.) 1908-1914, 1910-03-30

grade to keep the load from rolling
down the slope. 1t is independent
OF the nature of the road and de-
pends only upon it's angle of inclina-
tion Grades are ordinarily express
ed in terms of the rise or fall in feet
per hundred feet, or a per cent. of
the horizontal distance; thus |
per cent. grade means a rise or fall
Of ! foot in 100 feet. Under average
conditions. on good hard road a
work horse can draw up a short 10
per cent grade but one-third the
weight which he can draw on a level.
Up a longer per cent. grade but
two-thirds the weight which he can
draw on a level. In other words. to
reduce the grades at any time and all
points on road, from maximum of
10 TO D per cent. enables material or
merchandise to be transported over
the road for one-half the former cost
per ton per mile.
1t is necessary to have tractive
force of 5S pounds to haul ton II
miles, including the ordinary ve-
hicle over good macadam road on a
grade of l per cent, which would be
equivalent to hauling the same load
over u miles of level road On a
10 per cent. grade it would require a
tractive force of 23S pounds, which
would be equivalent to hauling the
same load over 6A miles of level
road, so you will see the importance
of reducing the grades on your roads
| might say that the width of tires
has little effect on traction when used
on a hard road bed, but assists very
materially in maintaining a per-
manently hard and smooth surface.
One of the most common defects of
ordinary country roads is that dis
tance has been saved by a disregard
of the desirability of easy grades.
The curving road around a hill may
often be no longer than the straight
one over it; for the latter is straight
only with reference to the horizontal
plane, but curved as to the vertical
plane, while the former is curved as
to the horizontal plane, but straight
as to the vertical plane. Both lines
curve, and the one passing over the
hill is the one called straight only
because its vertical curvature is less
apparent to the eye; for instance,
er up or down.
In the matter of grades a road
nearly level is the most desirable,
but as it can seldom be obtained we
have to take into consideration the
effect of grades upon the cost OF oper-
ating the road The grade may be
reduced by going around the hill
or by cutting down the hill If the
slope to be ascended is a long one
the first method should be EN-
ployed, but If the grade is short, the
second method is usually the better.
Increasing the length adds to the
cost of construction and of transpor-
tation, while cutting down a hill
adds only to the cost of construction.
In a broken or rough country
proper adjustment of the grades is
the most important part of road
building, and the better the road
service, the more necessary is such
an adjustment.
All grades are objectionable for
two reasons: First, because a grade
increases the amount of power re-
quired to move a load up it, and
secondly, because a grade may be so
steep as to limit the amount of the
load that can be moved over the road.
AS a chain is no stronger than its
weakest link, so a road is no better
than its steepest grade The fixing
of the proper maximum or ruling
grade is very important. On long
maximum grades 1t is wise to pro-
vide little stretch of nearly level
road upon which to let the team rest.
Considering only the cost of trans
portation level road is the best; but
II costs less to maintain a road upon
a slight grade than one perfectly
level. On any road longitudinal ruts
are liable to form and interfere with
the surface drainage and, there
fore. If the road is perfectly level in
its longitudinal direction, its surface