The Worthington advance. [volume] (Worthington, Minn.) 1874-1908, 1899-10-06

gin with, the subsoil, which is to serve
as foundation for the stone, must be
properly crowned, sloping down from
the middle to each side of the road, and
must then be rolled until it is abso-
lntely hard and smooth. The road
should take it's shape from the shape
of the foundation. The stone is but a
covering or roof for the protection Of
the ground beneath"
'"The stone used should be put down
in layers not more than four inches
thick, and it is we'll, where several lay
ers of stone are used, to sort the ma
terial and to use the larger pieces for
the lower layer. This sorting is done
by means of rotary screen attached
to the rock crusher. In building ma
cadam roads in Massachusetts and On
tario, the lower layer is usually COM
posed of stone which will pass through
hole 21z inches in diameter. The Sec
ond layer usually consists of pieces
which will pass through a 1h-inch
hole"
Rolling is the most important point
in the treatment of macadam or stone
roads. A heavy roller should always
be used, heavy enough to wedge the
pieces of stone firmly together. The
roller accomplishes this by shifting the
pieces about until each is lodged firmly
between adjoining pieces, which read
lily explains the greater effectiveness
of the heavy machine. Two things may
,,rovont c,,oooeef,,1 ro11;n~. o;+bar ~ -
failure to provide solid foundation,
or the practice, which is very common,
of spreading gravel or dirt over layer
Of stone before it is rolled. The idea
of using such a ''binder" is a bad mis-
take. In either event, the dirt or gravel,
getting between the loose particles Of
stone, will prevent their becoming firm
ly wedged. A mixing of stone and
earth, which is thus frequently brought
about in an attempt to build macad-
am road, is little better than an ordi-
nary dirt road; indeed, it is inferior in
some particulars. The material in a
road thus constructed is sure to shift
about under the pressure of narrow
tired wheels, which results in the larger
pieces of stone working their way to
the top, rendering the road rough and
uncomfortable for travel. The best
way to help the stone to ''bind" is to
thoroughly sprinkle it with water be-
fore and during the rolling process. AL
most every kind of stone has more or
less cementing qualities, and it's satura-
ton with water while it is being rolled
serves admirably to help unite the diff
ferent pieces firmly. The second layer
of stone is frequently of less thickness
than the layer below. This layer should
also be thoroughly and repeatedly
rolled without the use of gravel or dirt
as a supposed binder, and with the use
of abundant water to help in cement
ing it. After the layers of stone are
entirely completed and have been thor
oughly rolled and packed, it is we'll to
spread layer of gravel, by way of top
dressing, and to roll that thoroughly.
Better still is to make this layer of
stone screenings, which will unite bet
ter than gravel does. This dressing will
prevent wearing the macadam road
proper, and, as it disappears with use
and travel, should be renewed from
time to time, leaving the stone con-
struction below absolutely perfect"
"A macadam road, properly built and
with proper slope to each side, will read
lily drain off water and snow. The OBJ
ject of all road experts is to so construct
macadam road that water cannot per-
meate it. If water is allowed to find it's
way through the macadam road into
the foundation below, it is sure to work
mischief; and il the road is then SUBJ
jected to any considerable pressure
from the wheels of heavily-loaded wag-
ons, it is certain to give way. Hence,
the proper maintenance and care of
macadam road are as important as its
proper construction. If once the road
be damaged in this way, the work of de-
struction is bound to continue. It is,
therefore, as important to prevent this
first damage as it is to prevent the first
small hole in dam.''
''Taxpayers, who are obliged to con-
tribute to the cost of macadam roads,
will do we'll to see to it that the work
is properly done. The old adage that
what is worth doing at all is worth do
ing well applies with irresistible force.
Many of us still believe that we cam
not afford, in the United States, to build
frst-class highways. It is even more
emphatically true that we cannot af-
ford to waste money in unsuccessful at
tempts at macadamizing.'