d the number of people benefited are
increased in direct proportion to the improvement of their surface.
Moreover, it is evident that a farm four or five miles from the market
or shipping point located on or near a hard road is virtually nearer the
market than one situated only two or three miles away, but located on a
soft and yielding road. Hard roads are divided here into three
classes--gravel, shell, and stone.

Although it is impracticable, and in many cases impossible, for
communities to build good stone roads, a surface of gravel may
frequently be used to advantage, giving far better results than could be
attained by the use of earth alone. Where beds of good gravel are
available this is the simplest, cheapest, and most effective method of
improving country roads.

[Illustration: GRAVEL ROAD NEAR SOLDIERS' HOME, DISTRICT OF
COLUMBIA]

In connection with the building and maintenance of gravel roads the most
important matter to consider is that of selecting the proper material. A
small proportion of argillaceous sand, clayey, or earthy matter
contained in some gravel enables it to pack readily and consolidate
under traffic or the road roller. Seaside and river gravel, which is
composed usually of rounded, waterworn pebbles, is unfit for surfacing
roads. The small stones of which they are composed, having no angular
projections or sharp edges, easily move or slide against each other, and
will not bind together, and even when mixed with clay may turn
freely, causing the whole surface to be loose, like materials in a
shaken sieve.

Inferior qualities of gravel can sometimes be used for foundations; but
where it becomes necessary to employ such material even for that purpose
it is well to mix just enough sandy or clayey loam to bind it firmly
together. For the wearing surface or the top layer the pebbles should,
if possible, be comparatively clean, hard, angular, and tough, so that
they will readily consolidate and will not be easily pulverized by the
impact of traffic, into dust and mud. They should be coarse, varying in
size from half an inch to an inch and one-half.

Where blue gravel or hardpan and clean bank gravel are procurable, a
good road may be made by mixing the two together. Pit gravel or gravel
dug from the earth as a rule contains too much earthy matter. This may,
however, be removed by sifting. For this purpose two sieves are
necessary, through which the gravel should be thrown. The meshes of one