care should be taken not to place latrines near existing wells, nor to
dig wells near where latrines have been placed. The necessity of these
precautions to prevent wells becoming polluted is obvious. Screens
made out of any available material are, of course, required for
latrines. This arrangement applies to a temporary camp, and is only
admissible under such conditions.

A deep trench saves labor, and places the refuse in the most
immediately safe position, but a buried mass of refuse will take a
long time to decay; it should not be disturbed, and will taint the
adjacent soil for a long time. This is of less consequence in a merely
temporary encampment, while it might entail serious evils in
localities continuously inhabited. The following plan of trench has
been adopted as a more permanent arrangement in Indian villages, with
the object of checking the frightful evil of surface pollution of the
whole country, from the people habitually fouling the fields, roads,
streets, and watercourses. Long trenches are dug, at about one foot or
less in depth, at a spot set apart, about 200 or 300 yards from
dwellings. Matting screens are placed round for decency. Each day the
trench, which has received the excreta of the preceding day, is filled
up, the excreta being covered with fresh earth obtained by digging a
new trench adjoining, which, when it has been used, is treated in the
same manner. Thus the trenches are gradually extended, until
sufficient ground has been utilized, when they are plowed up and the
site used for cultivation. The Indian plow does not penetrate more
than eight inches; consequently, if the trench is too deep, the lower
stratum is left unmixed with earth, forming a permanent cesspool, and
becomes a source of future trouble. It is to be observed, however,
that in the wet season these trenches cannot be used, and in sandy
soil they do not answer. This system, although it is preferable to