The Farmville herald. [volume] (Farmville, Va.) 1890-1934, 1901-02-22
THE USE OF GRAVEL.
"o"d Huilding Instructions PromuI-
gated by the Wisconsin State
Experiment Statfon.

Experiment station.
As gravel is the material chief,
used for the improvement OF countr,
roads the following instruction.
taken from a bulletin issued by III,
Wisconsin experiment station will b.
of interest to many of our readers:
+ IL occasionally happens that nat.
urai gravel beds are found which pos.
sess the right characteristics for max.
ing roads, and when the gravel is lust
right excellent roads may be made
from IL.
There are several important feat.
ures which a good road gravel must
possess:
]. There must be one prevailing
SIZE Of pebble in sufficient quantity SO
that when thoroughly rolled they
press against one another.
?. There must be enough Of m,
hrer sizes q coarse sand and fins
gravel to fill the yoids between IN.
coarser gravel.
B. There must be enough Of fine
loan TO fill the voids between m,
coarse sand and fine gravel and retain
a sufficient amount OF water IN hino
the sand grains together and prevent
their rolling.
4. The coarse and fine gravel and /
,ne sand must be made up Of more OF
less angular fragments in order thai
nat faces Of rock may set togetbe,
and thus lessen the danger OF rollino
and Of crushing under the weight OF
the load.
IL Is not possible 10 give specific
copcise directions for identifying y
good road gravel, but a man who has
seen and worked with it readily rec
ognizes it.
IL VIII be apparent at once that the
several characteristics which have
been pointed out are not likely often
TO occur together in just the right
ratios; and so there will be all nos.
Sible gradations from the ideal gravel,
10 those which will not answer at all
indeed 1t must be said that most
gravel beds have had the finer mate.
'ials so completely washed out that
'nly clean sand and gravel remain:
ma when this is true it is useless tc 4,
ry TO make a road with II. Such ma. }
erlals can only be used 10 temper a
DAD which is too clayey in its texture
y reducing its water capacity. .
IL happens in the majority of case, +,
nat much Of the gravel is too larg. q
nj too rounded to permit close pack. +
1g and fast binding. When this Is =
rue much better qualities may b. 4
'cured by using either the crusher OF $
he screen, or both together. II will q
at once apparent that where much d
the gravel is too coarse, to run Il is
trough the crusher so as 10 reduc. m
ne material 10 a more uniform siz. n,
ld at the same time TO increase ths n
lgularity Of the fragments will make d,
much better road material 10 use &c
ther by itself, to build a road OF O, III
a tempering material. n,
There are many deposits OF gravit, eli
ny which it might appear would h.
axe a good road material. but the %
lnciple must be kept always in mind bo
at too much Of too fine material tn
j take in and retain so much waite, flo
at the binding quality OF the water de
lost -nese gravelly clays occur IN di;
my OF the hills Of the glaciated DOR. tic
ms OF the United Dtates and through otl
ich roads are often cut. me
n the construction of a gravel road Gil
In that OF stone road, II is OF pie
me Importance 10 secure first ot he
properly shaped and Thoroughly Z
led and frmed roadbed before anv ing
lvel is laid on. When this has been daI
le, and a suitable gravel has been par
nd. the next step is 10 spread even. for
over the surface and thoroughly mo
a layer which, when finished. will Am
asure three inches thick.
n the rolling II will be important ~
hrm the outer edges OF the gravel
IN order that the rolling NAV not Mel
e it outward and destroy the slope
uld the gravel be too dry TO pack
must be moistened or the work be
pended to take advantage Of the II
IS. kno
o make a good road there should war
lot less than three three-inch Law. thai
and usually four will be better lsol
course a road six inches thick will IN
a great improvement, and often aos'
re the travel is light and the Ooi'
bed thoroughly made tbroo - Evei
ood gravel. well placed will make ~ G.
reat improvement in the road. eity
ing as a wearing surface. iarS
part