AND GROUND SURFACES. 
43 
in half the time required to dry the sticky surface of the other part 
of the field. The advantage did not stop here. The porous char- 
acter given to the soil by the formation of innumerable and invisi- 
ble channels in a vertical direction down through the earth to the 
drains below, had such a tendency to lighten the ground that it 
became much more capable than the harder-surfaced soil to resist 
drouth; and was just as much moister in very dry weather as it 
was dryer in wet weather. This is in consequence of the fact, 
well known to cultivators, that the more porous and deeply worked 
a soil is, the greater is its power of absorbing moisture from the 
atmosphere in times of drouth. In sandy soils with clay sub- 
stratum the effect of drainage is quite as striking in its effect on 
the growth of plants and trees as in clayey lands, though not so 
necessary for comfort in walking upon, or working the soil. A 
wet sandy soil is more apt to be cold and sour than a clayey soil, 
notwithstanding its more comfortable surface ; and the sandy loams 
known as “ springy,” which have veins of quicksand not far below 
the surface, are those which most need drainage, and which are 
most difficult to drain well. 
The top of a hill, or a steep hill-side, is as likely to need sub- 
soil drainage as the bottom of a valley. It is the nature of the sub- 
soil in each case, that renders drains necessary or superfluous, and 
not the relative altitude of the location. Land surveyors are 
familiar with the fact that swamps are most numerous in the 
neighborhood of summit-levels. 
Tile and other earthernware pipes are the best materials 
for common drains ; and for garden and suburban lot drainage, 
should be put down from three to four feet below the surface. 
Professional drainers, or tilers, who use long narrow spades and 
hoes can put down drains four or five feet deep with a small dis- 
placement of soil, and so rapidly that it is not an expensive opera- 
tion to drain thoroughly a half acre or acre suburban lot by a 
series of drains not more than twenty feet apart, provided there is 
a sewer or other good outlet near by. Persons who are about to 
build on suburban lots which require drainage, should have the 
work done in connection with the house main drain, which is 
usually deep enough to be used as a trunk drain for the land ; and 
