elve hours out of the
twenty-four, so that the rate would be twice the average rate, and with
this correction, two quarts of water could be drawn in five minutes.

But even this is too slow, and if one were to take a quart cup to a
kitchen faucet and note the time necessary to fill the measure with the
water running at a satisfactory rate, he would find that unless the cup
was filled in about ten seconds it would be considered too slow a flow.
Since it is possible for more than one fixture to be in use at the same
time, the pipes ought to be able to deliver the total amount running
from different faucets open at the same time, and if it is considered
possible for three faucets to run at once, as, for instance, the kitchen
faucet, bath-room faucet, and barn faucet, then the supply pipe must be
able to deliver, under our assumption, three quarts in ten seconds, or
at the rate of about six thousand gallons a day. It is necessary,
therefore, to distinguish carefully between the total quantity of water
used per day and the rate at which such water is used.

The first of these requirements governs the size of the reservoir from
which the water comes or the yield of the well or spring, or the
capacity of a pump from a pond to a distributing tank; the other
requirement governs the size of the pipe or faucet or the capacity of a
pump which supplies direct pressure. It should be noted also that with
ordinary fixtures, the rate of delivery and the corresponding sizes of
the fixtures are not affected by the number of persons in the house,
whereas the first requirement, that is, the total quantity of water used
per day, is directly affected by the number of persons.

_Variation in maximum rates of water-use._

The quantity of water used, however, is not uniform throughout the day
or the week. It is commonly known, for instance, that on Monday, or
wash-day, when the well is the only supply, a great deal more water has
to be carried on that day than on any other day in the week, and this
same increased demand for water is made when the water comes in pipes
into the house. Probably about half as much water again is used on
Monday as on other days.

Again, in the hot weather of summer, more water is used for bathing and
laundry purposes than in cold weather. But, on the other hand, there is
a great tendency in cold weather to let the water run in a slow stream
from faucets in order to prevent freezing. This has been found to just
a