Judith Gap journal. [volume] (Judith Gap, Mont.) 1908-19??, 1912-06-07

between tho larger pieces. Gravel OBJ
tanned from streams Ia usually inferior
to pit gruvel for the reason that the ac-
ton Of the water has worn the pebbles
smooth and practically all the fine
binding material has been removed by
the Same agency. Even II clay OF loam
II mixed with river or creek gravel the
result Is not likely to Ike as satisfactory
~ that obtained By the use Of pit grav-
el. Fit gravel frequently contains too
gravel may have too much sand. In
such cases 1t Is sometimes advisable to
screen the gravel SO as to eliminate the
material which Is too fine or that which
II too coarse. The screef should DO
similar to that which il used in pre-
pairing material for 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 tho
material over the road surface. 1t
will often he found 'adviSa biz to spread
a thin layer OF such binding material
over the surface after the material has
been distributed and rolled. aud after
this the surface should be spriukled
and rolled again Or else rolled wMle
still damp from the rains.
A large part OF the gravel found in
the Atlantic coastal plane IL sufficient
y fine and uniform to render unneces-
sary any asserting for road building
purposes. but when the gravel. cspe-
cially that which il to constitute the
surface layer. contains large pebbles
these should be removed and either
thrown aside or else raked into the
foundation or recrushed. At least 80
per cent by weight Of the gravel should
be pebbles above one-eighth inch in
size, and there should be no pebbles in
the bottom layer that will not pas.
through 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-hnlf inch ring.
Not over 20 per cent Of the mass
should be clay. and this should be uni
f0rmly mixed and should contain no
large Jumps. Ten or Is per cent Of clay
produces better results than 70 per cent.
II the foundation or roadbed IL loose
it should be carefully rolled. 1t IL
quite ~ important to have solid
foundation for a gravel road az for
macadAm 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. II gravel IL abun-
dant. however, these shoulders may be
built Of gravel instead Of with earth.
or the road may be surfaced with
gravel nom shoulder to shoulder. II
the compacted depth Of the gravel
road is to be eight inches and the
width twelve feet it will take about
1850 cubic yards 0f gravel to the mile.
and It IL 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 b. dumped direct
" on the road. a. this viii usually re-
SASS IA IVA8us uu0NC0 bOIIaC0. AZ
specially devised spreading wagons
are not used the gravel should be
dumped on boards and spread from
them on to the road.
Tho gravel should be placed ON the
road commencing at the end nearest
the gravel pit, in order that tho teams
will aid in packing the material. A
spike or tooth harrow may be used to
advantage in spreading the material
but II the gravel contains only a small
amount OF binding material the har-
row should not b used. AZ It will 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 surface il thoroughly
compacted. The surface layer should