s best), and put the other
end of the tube over a piece of glass tubing not less than
5 or 6 inches long. Hold up the glass tube and the funnel,
letting the rubber tube sag down between them as in Figure
1. Now fill the funnel three fourths full of water. Raise the
glass tube higher if the water starts to flow out of it. If
no water shows in the glass tube, lower it until it does.
Gradually raise and lower the tube, and notice how high the
water goes in it whenever it is held still.

This same thing would happen with any shape of tube or funnel. You
have another example of it when you fill a teakettle: the water rises
in the spout just as high as it does in the kettle.

[Illustration: FIG. 1. The water in the tube rises to the level of the
water in the funnel.]

WHY WATER FLOWS UP INTO YOUR HOUSE. It is because water seeks its own
level that it comes up through the pipes in your house. Usually the
water for a city is pumped into a reservoir that is as high as the
highest house in the city. When it flows down from the reservoir, it
tends to rise in any pipe through which it flows, to the height at
which the water in the reservoir stands. If a house is higher than the
surface of the water in the reservoir, of course that house will get
no running water.

WHY FIRE ENGINES ARE NEEDED TO FORCE WATER HIGH. In putting out a
fire, the firemen often want to throw the water with a good deal of
force. The tendency of the water to seek its own level does not always
give a high enough or powerful enough stream from the fire hose; so a
fire engine is used to pump the water through the hose, and the stream
flows with much more force than if it were not pumped.

_APPLICATION 2._ A. C. Wheeler of Chicago bought a little farm
in Indiana, and had a windmill put up to supply the place with
water. But at first he was not sure where he should put the
tank into which the windmill was to pump the water and from
which the water should flow into the kitchen, bathroom, and
barn. The barn was on a knoll, so that its floor was almost as
high as the roof of the house. Which would have been the best
place for the tank: high up on the windmill (which stood on
the knoll by the barn), or the basement of the house, or the
attic of the house?

[Illustration: FIG. 2. Where is the best location for the tank?]

_APPLICATION 3._ A man was about to open a garage in San
Fr