clarify the water
supply.

Water that is not known to be pure should be boiled 20 minutes; it
should then be cooled and aerated by being poured repeatedly from one
clean container to another, or it may be purified by apparatus
supplied for the purpose.

Arrangements should be made for men to draw water from the authorized
receptacles by means of a spigot or other similar arrangement. The
dipping of water from the receptacles, or the use of a common drinking
cup, should be prohibited.

In the field it is sometimes necessary to sterilize or filter water.
The easiest and surest way of sterilizing water is by boiling. Boiled
water should be aerated by being poured from one receptacle to another
or by being filtered through charcoal or clean gravel. Unless boiled
water be thus aerated it is very unpalatable and it is with difficulty
that troops can be made to drink it.

Filtration merely clarifies--it does not purify. The following are
simple methods of filtration:

1. Dig a hole near the source of supply so that the water may
percolate through the soil before being used.

2. Sink a barrel or box into the ground, the water entering therein
through a wooden trough packed with clean sand, gravel or charcoal.

3. Place a box or barrel in another box or barrel of larger size,
filling the space between with clean sand, gravel, moss or charcoal,
and piercing holes near the bottom of the outer barrel and near the
top of the inner. The filter thus constructed is partly submerged in
the water to be filtered.

4. Bore a small hole in the bottom of a barrel or other suitable
receptacle, which is partly filled with layers of sand, gravel, and,
if available, charcoal and moss. The water is poured in at the top and
is collected as it emerges from the aperture below.

The amount of water used by troops is usually computed at the rate of
five gallons for each man and ten gallons for each animal per day.

=1254. Rules of sanitation.= The following rules of sanitation are to
be observed:

Men should not lie on damp ground. In temporary camps and in bivouac
they raise their beds if suitable material, such as straw, leaves, or
boughs can be obtained, or use their ponchos or slickers. In cold
weather and when fuel is plentiful the ground may be warmed by fires,
the men making their beds after raking away the ashes.

When troops are to remain in camp for some time all underbrush is
cleared away and the camp made as comfortable as