The record-union., 1893-05-24
GRAVEL UNECONOMIC FOR HIGH
WAYS AND STREETS.

Engineer W. E. McClintock, in the
Engineering Magaeme, tells US what all
road builders ought to know, that gravel
is not the most economical material for
highways. Mr.. McClintock is one of the
Massachusetts Highway Commission,
and has had official occasion to test the
uses of gravel.
We have long believed that Sacramento
City was in error in graveling her streets;
and Sacramento County uneconomic in
graveling her roads. Recent observation
convinces US. Broken stone would have
given us far more satisfactory highways,
and far less expensive ones in the long
run. Broken stone would cost more in
the outset, but when we come to consider
the question of continuous repairs, be-
ginning with the very first season after a
new graveled surface has been made, the
expensiveness of such surfaces develops.
Mr.. McClintock dwells long upon this
point. Certainly no observing citizen of
Sacramento can be found who will not
/ concur in his judgment. We have tried
graveled streets for twenty years, and it
is verdict not to be set aside that they
have cost us about three times the outlay
good macadam would have necessitated.
Mr.. McClintock says:
The general principles of broken stone
roads are the same now as they were when
Macadam first introduced his system With
modern machinery Tor breaking ami rolling
we can obtain bett. results in quicker time
and less care has TO be exercised in Watching
the road as 1t hardens. But the greatest care
has to be used in every detail Of the cOnstruc-
ton. These roads have been constructed for
the most part on a undatiOn of sandy loan,
but none that l am aware OF in clay or heavy
soil. The soil was first compacted by rolling
the crown conforming to that of the finished
roadway. ON the prepared foundation the
broken stone was laid about four and half
inches thick. This was lightly rolled by pass
ing The steam-rOller about four times over it
Sand was then carefully spread over the sur
face as the roller passed back ana forth until
the interspaces were thoroughly ulled to the
tops Of the stone. Alb Jut one inch OF broken
stone screenings whicl h&d passed through
half-ncn screen We're then laiu on, watered
and thoroughly rolled until the surface be
came even and firm.
This is not difficult process. 1t en-
tails something more Of labor than does
the usual loose method of making a
graveled road. But here is the economic
difference: The broken stone always
turns its fiat side to the pressure of a
wheel and its irregular side is pushed or
ground down, making a smooth, hard
surface. With gravel the stone is round;
it never crushes it grinds out the
bed in which it lies, and repeat ed
wheel contacts with it result in rut
which steadily enlarges. Gravel stone
always works to the surface and crowds
from the track to the sides of the grade;
broken stone sinks or grinds to COM
mon level, and becomes immovable in
its bed.
derstand who reflects on the mat
| ter a moment, is a decided economy
in the use of the broken stone, since it
reduces the obstacles presented to the
wheel to the fewest possible; lessons the
/ strain upon vehicle, harness, and animal
/ power; conserves speed and heavy
loading, and, above all, calls for the
least of road cleaning and street re-
pairing. Whereas, with our graveled
roads precisely opposite conditions pre-
vail.
Let US adopt the policy Of patting all
local convicts at work upon stone break
ing for use on the city and county high
ways; let gravel be abandoned and
broken stone surface for highways be
the road rule, and the result will be the
removal of the reproach which
certain qualities of gravel consti-
/ tute, notably in the wet season;
largely reduced repair bill, greatly ex-
tended life of the road, enhanced comfort,
and gratifying saving in time and il
money to all who use the roads.