tank in the attic, the pressure in the bath-room
being not more than ten feet, and while the water flowing through a
three fourths inch pipe was noticeably slow, it was not so slow as to
discredit the supply.

A height or head of twenty feet above the highest fixture in the house
would be better and ought to be secured whenever possible. This head is
obtained by having the source of supply higher than the highest fixture,
not merely the twenty feet mentioned, but also an additional height
necessary to offset the frictional losses caused by the running water.
The loss from this source in case of fire supply has already been
referred to, but for purely domestic supplies the loss is appreciable.
The maximum rate as already indicated is not more than 7000 gallons per
day, whereas the fire rate both for single houses and for a small hamlet
is about a million gallons a day. For the lower rate, as well as for
rates one half and twice this rate, the friction loss in vertical feet
per 100 feet run in small pipes is shown in the following table:--

TABLE X. SHOWING LOSS OF HEAD BY FRICTION, FOR DIFFERENT QUANTITIES OF
FLOW, AND IN DIFFERENT SIZES OF PIPES

========================================================================
Rate of Flow | | | | |
in Gallons | | | | |
Per Day | 1/2" Pipe | 5/8" Pipe | 3/4" Pipe | 1" Pipe | 1-1/4" Pipe
-------------+-----------+-----------+-----------+---------+-------------
3500 | 13.95 | 4.81 | 2.35 | 0.66 | 0.25
7000 | 47.17 | 17.30 | 7.45 | 2.04 | 0.74
14000 | 163.09 | 57.8 | 25.00 | 6.64 | 2.41
========================================================================

The table shows how much additional elevation is needed over the 20 feet
already referred to. For example, suppose it is decided that a rate of 1
quart in 10 seconds is to be maintained from three faucets or a rate of
7000 gallons per day. Suppose that a pond 4000 feet away is found to be
50 feet above the highest faucet in the house, and it is a question what
size pipe ought to be used. By the table a 1-inch pipe loses 2.6 feet
per 100 feet or 104 feet in the 4000 feet, an impossible amount when
only 50 feet are available, although the size would be entirely proper
if the difference of level was 124 feet or anything greater. A
1-1/4-inch pipe, however, lose