in most cases, were omitted, much of the surface water would soak into
the ground between the sidewalk and the pavement, doing much good to
trees, shrubs, and grass. The roots of the trees naturally extend as
far, or farther, than their branches, and for their good the ground
under the pavement and sidewalk should be supplied with a certain amount
of moisture.

[Illustration: VI. A tree that gives character to a place.]

[Illustration: Fig. 69. A common form of edge for walk or drive.]

[Illustration: Fig. 70. A better form.]

"The arrangement made for the removal of surface water from the street
must also take care of the surplus water from adjacent lots, so there
is a practical advantage in having the level of the street lower than
that of the ground adjoining. The appearance of houses and home grounds
is also much better when they are higher than the street, and for this
reason it is usually desirable to keep the latter as low as possible and
give the underground pipes sufficient covering to protect them from
frost. Where the ground is high and the sewers very deep, the grades
should, of course, be determined with reference to surface conditions
only. It sometimes happens that this general arrangement of the grades
of home grounds, which is desirable on most accounts, causes water from
melting snow to flow over the sidewalk in the winter time, where it may
freeze and be dangerous to pedestrians. A slight depression of the lot
away from the sidewalk and then an ascent toward the house would usually
remedy this difficulty, and also make the house appear higher.
Sometimes, however, a pipe should be placed underneath the sidewalk to
allow water to reach the street from inside of the lot line. The aim in