l.1
    The elevated tank or gravity system is generally the cheapest to install.
it requires a tank having an inlet, an outlet, and safety overflow leading
into a sink or drain. The tank may be placed in the attic of the house if
for
house use only, or in the barn, on a tower or buried in a near-by hill. The
objection to a tank in the house is that the size is limited on account of
the
weight of the water.
    The tank may be made of wood, concrete or steel. Wood is the best
material to use for the tank. It does not sweat, will not rust, less trouble
                           to erect, easier to keep from freezing, and will
When a gravity system will last 15 to 20 years. Where a large capacity is
distribute it for you.   necessary, steel or concrete must be used. In
                            the northern part of the state an exposed tank
will give trouble unless well protected. A tank must be high to provide
enough pressure to be of service, at least six feet above the point of delivery
for every 100 feet of x inch pipe through which the water flows. Tanks
are heavy and must be supported by heavy timbers. A good location for a
gravity tank is in the hay mow. A tank made of steel six feet in diameter
and eight feet deep will hold 1,688 gallons. It would cost you not over $100
to install this tank. This figure includes tank, 200 feet of lead pipe for
the
house, fittings and labor of installing.
     In an air and water (or hydro-pneumatic) system, air and water are
stored in an air tight tank. It is an improvement over the elevated system
                           because the tank can be placed in the basement
When air will do the job. of the house or in the ground near the well.
                           An outfit large enough for a family of six, water
 for six horses, 20 head of cattle, and 10 hogs, can be installed for $200.
              Tank 4 feet x 16 feet ................$ 150.00
              Power pump ..........      .              40.00
              Pipe fittings .......................  5.00
              Air gauge and water glass  .  .......   5.00
                       Total .............$ 200.00
   small tank for house use only could be easily installed for $100.00.
     The principle on which this system operates is, as water is pumped in
     the bottom and rises, the air above is compressed. This pressure is
in-
   eased depending upon the amount of water forced in. The expansion of
   .e air forces the water out. This system, to be successful, must be pro-
   *ded with a pump which will pump both air and water-separately or at the
 -tme time. Extra amounts of air will be needed from time to time to pre-
   nt waterlogging, for as water is drawn from the tank air is absorbed by
   and carr'ed out so that fresh air must be supplied to take care of this
loss.
     The power required to run such an outfit is small. A 2-horse power
   tgine would furnish -this power besides enough power for other home con-
 viniences. A windmill would furnish ample power.
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