s only 0.74 foot in 100 or 39 feet per
mile, so that the 1-1/4-inch pipe would be necessary, although that size
would answer even if the pond were a mile and a quarter away.

When water from a well is pumped to an elevated tank there is the same
necessity of providing about 20 feet difference in level between the
tank and the highest fixture, but the length of pipe involved being
small, the friction losses are not great. It should be noted even here
that too small a pipe may reduce the pressure, a 1/2-inch pipe causing a
loss of 47 feet in a 100-foot pipe line. If a tower is built by the side
of the house, the distance down to the ground, across to the house, and
up to the second floor would hardly be less than 50 feet, and this is a
loss of 23-1/2 feet, which means that the tank would have to be set
higher in the air by this amount. With a 3/4-inch pipe, it should go 3.7
feet, and with a 1-inch pipe but a foot higher than the level necessary
to make the water flow out of the faucet at the rate already specified.

CHAPTER VII

_QUALITY OF WATER_

A pure water-supply has always been regarded as desirable and its value
can hardly be overrated, from the standpoint of health, happiness, or
economy. From the earliest history, no crime has been so despicable as
that of deliberately poisoning a well from which the public supply was
obtained, and in the past no charge more quickly could stir the populace
to riot. In Strassburg in 1348 two thousand Jews were burned for this
crime charged against them; and as late as 1832 the Parisian mob,
frantic on account of the many deaths, insisted that the water-carriers
who distributed water from the Seine, shockingly polluted with sewage as
it was, had poisoned the water, and many of the carriers were murdered
on this charge.

Yet no water, as used for drinking purposes, is absolutely pure,
according to the standards of chemistry. Distilled water is the nearest
approach to pure water obtainable, and it is said by physicians that
such water is not desirable as a habitual and constant beverage. The
human body requires certain mineral salts particularly for the bones and
muscles, and while these salts are provided in a large measure by food,
a number are also furnished by drinking water. On the other hand, a
wonderful natural process is accomplished by distilled or approximately
pure water in that the water tends to dissolve, to add to itself, and to
carry away whatever excess o