The Bennington evening banner. (Bennington, Vt.) 19??-1961, 1912-07-10

screen The gravel so as TO eliminate the
material which is too fine or that which
is too coarse. The screen should be
similar to that which is used in pre-
pairing material for a macadam road,
| In the handling Of the gravel care
should be exercised not TO separate the
binding material from it, nor should
this binding material be allowed to
settle to the bottom in spreading the
material over the road surface. 1t
will often be found advisable to spread
thin layer Of such binding material
over the surface after the material has
been distributed and rolled. and after
and rolled again or else rolled while
still damp from the rains.
A large part of the gravel found in
the Atlantic coastal plane is sufficient
! ly fine and uniform. to render mueces-
sary any asserting for road building
purposes, but when the gravel, espe-
q ~ that which is To constitute the
surface layer, contains large pebbles
these should be removed and either
thrown aside or else raked into the
| foundation or recruShCd At least 60
per cent by weight OF he gravel should
be pebbles above one-eighth inch in
size, and there should be no pebbles in
the bottom layer that will not pass
| through n two and half or three inch
ring, and In the top layer there should
be no pebbles which will not pass
| through "A one and one-half inch ring.
Not over 20 per cent of the mass
should be clay. and this should be uni
| formly mixed and should contain no
large Jumps. Ten or 10 per cent of clay
produces better results than 20 per cent.
IL the foundation or roadbed is loose
II should be carefully rolled II is
quite as important to have solid
foundation for gravel road as for
macadam road Gravel will compact
to about 50 per cent Of its depth. loose
measure. provided earth shoulders are
placed on both sides of the road to
prevent the wasting away OF the
gravel on the sides. If gravel is album
dant. however, these shoulders may Ice
built Of gravel instead of with earth.
or the road may be surfaced with
gravel from shoulder to shoulder II
the compacted depth Of the gravel
road is TO bee eight inches and the
width twelve feet il will take abSut
$3.50 cubic yards OF gravel to the mile.
and It Is best to make the first layer
about six inches in depth. loose meas
ure. and the second layer about four
inches in depth, loose measure
Gravel should not be dumped direct
ly on the road. as this VIII usually re-
suit in a rough, uneven surface. If
specially devised spreading wagons
are not used the gravel should be
dumped on boards and spread from
them on TO the road.
The gravel should be placed on the
road commencing at the end nearest
the gravel pit. in order that the teams
will aid I'm packing the material. A
spike OF tooth harrow may be used TO
advantage I'm spreading the material.
but II the gravel contains only a small
amount OF binding material the har-
row should not be used. as Il will have
the effect Of bringing the larger peb-
bles to the surface and shaking the
binding material to the bottom.
Each layer II gravel should be rolled
separately. The rolling should begin
at the sides and continue toward the
center until the surface is thoroughly
compacted. The surface layer should
be sprinkled while the rolling T. in
progress. but II a roller and sprinkler
are not available the road should be
constructed IL possible in the spring Of
the year. as the successive rains will
cause the material 10 pack much better
than IL the road were built in the dry
hot summer OF early fall.
II the gravel Is lacking In suitable
binding material and clay or loam Is
available a limited quantity Of such
material may be spread over the sur
face. The clay should be used very
spsringly. however. as Il ahsorbs wa
ter and causes the road to become soft