Lancaster daily intelligencer. [volume] (Lancaster, Pa.) 1864-1928, 1890-03-08
NTH

HALE OF CROSS SECTION.


"If the stone for the foundation--for
which most anything will do, and that.
kind should be taken which is cheapest
TO procure--happcns to be got out cheap
est in larger pieces than the above dimen-
sions, 1t will do no harm. This founda-
tion course Is sometimes set SO as 10 pre-
sent an inclination on top, and the cover
then put on Of uniform thickness over
the whole breadth. This is perhaps best,
but Is somewhat more expensive. 1t will
do, in nearly all cases, to set the founda-
tion course on level, or as near SO as
the stones will allow, and then make the
top crowning, by making the covering
say three-quarters Of an inch or m inch
less thick at tho edges than In the center.
The stones forming the foundation should
not be set In rows, nor ever laid on their
fat sides, but set up on edge and made
to break joints as much as possible: that
10, set up irrcgularly, After they are set
up, the points that project above tho
general level may bc broken off, and the
interstices generally filed up with small
stone.
'More or less care and work are neces-
sary in this part Of tho operation accord
ing to tho Importance Of the road and
the depth and character of the material
used for the top covering. To roll tho
road at this stage is to he recommended;
afterwards it becomes q requisite. The
point never TO bc lost sight of is that this
foundation course must remain porous,
must be pervious to water, SO that all
rain water that shall soak through tho
top covering will find through it means
OF escape to the ground underneath;
thence. according to the nature of the
subsoil, II is left either to soak into the
ground or must be further led away by
appropriate drains"
Another authority in the same work,
writing upon the top surface for stone
road. says:
Experience has shown that while six
inches may be sufficient depth for light
travel, twelve to eighteen inches are
necessary IL heavy loads must be carried
at all seasons of the year. For country
macadam roads the limits would he be-
tween six and twelve inches, according
to the character of the subsoil. For tho
thorough construction of macadam roads
the stones are now crushed by machinery
and then rolled with steam road rollers
of ten to fifteen tons weight. The weight
of the roller per square inch on the bear
ing surface should be equal to the ex.
pected weight, per square inch, under
the wheels of the heaviest loads.
"Where thorough work of the best
character is wanted, engineering skill
and experience are requisite, but the gen
eral methods may be briefly stated, 80
that wherever bad sloughs need filling up
with stone, the macadam plan may be
followed at least approximately. The
trench or road bed should be dug out to
the required width and depth, the larger
stones should then be selected and firmly
packed together across the foundation
in irregular courses, in the general form
of a street pavement. They should all
rest on their fiattest or broadest surfaces,
and the thin or Jagged edges upward.
The lnterstices or spaces should be close
ly filed up with chips and the whole
layer be well rammed or rolled into
solid mass.
ION top of this place layer Of finely
broken stone of the thickness requisite
to bring the surface TO grade, with
good crown in the center. This should
be rolled until the whole mass is firmly
bound together. and then covered with
sharpgravel or fine screenings of broken
stones of sufficient depth to bed and bind
the layer of broken stone. In the future
maintenance of such road the most i'm
portant point is TO prevent the formation
OF ruts, by keeping the surface so uni
formly even that there will be no induce
ment for travel to follow beaten tracks.
The cost of the macadam structure pre-
cludes its use on country roads, except
in occasional bad spots where stone is
necessary"