Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1912-09-05

lSt"tfus tHc ta1 ktI HtSNEs. utsthtl W
tained from stre:ims h usually inferior
to pit gravel for the reason that the ae-
ton OF the water has wern the pebbles
smooth aud practically all the fine
binding material has been removed by
the 81 me agency. Even il clay or loan
Is mixed with river or creek gravel the
result is not likely TO be as satisfactory
as that obtained by the use of pit gray.
el. Fit gravel frequently contains too
much clay or earthly matter. while river
gravel may have too much sand. In
such eases il is sometimes advisable te
screen the gravel 50 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 tie handling OF the gravel care
should he exercised not to separate the
binding material from it, nor should
this binding material be allowed ia
settle TO the bottom in spreading the
material over the road surface. IL
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
this the surface should be sprinkled
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
II fine and uniform to render unneees-
gary any asserting for road building
purposes. but when the gravel. rspe-
cially 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 recrrfsheti. At least 60
per cent by weight of the gravel should
be pebbles above one-eighth inch in
size, aud there. should be no pebbles in
the bottom layer that will not pass
through a two and a half or three inch
ring, and in the top layer there should
be no pebbles which will not pass
through 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 Is per cent of clay
produces better results than 20 per cent.
If the foundation or roadbed is loose
it should be carefully rolled. 1t is
/ quite as important to have solid
foundation fora gravel road as for q
maeadam road Gravel will compact
to about so 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 be
built of gravel instead OF with earth.
or the read may be surfaced with
gravel from shoulder to shoulder II
the cornpactea depth OF the gravel
road is to be eight inches and the
width twelve feet it will rake abelit
900 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
sly on the road, as this win usually re-
suit in a rough. uneven surface. IL
specially devised spreading wagons
are not used the gravel should be
dumped on boards and spread from
them ON TO the road.
The grarel should be placed on the
road commencing at the end nearest
the gravel pit, in order that the teams
will aid in packing the material A
spike or tooth harrow may be used to
advantage in spreading the material.
but If the gravel contains only a small
amount Of binding material the har-
row should not be used, as it viii have
the effect of bringing the larger peb-
bles to the surface and shaking the
binding material to the bottom
Each layer Of gravel should be rolled
separately. The rolling should begin
at the sides and continue toward the
center Until the snrfare is thoroughly
compacted The surface layer should
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