ls could be substituted for these
pillars and all the coal could be taken out.

In using the coal we waste about another quarter. Stoves and furnaces
are usually built so poorly that a large part of the value of the coal
escapes as gas and smoke. In large cities and manufacturing districts
the smoke becomes a great nuisance. In the making of coke from coal,
enormous quantities of coal tar and gas have been lost. Most engines
consume a far greater amount of coal than they should in doing a given
amount of work. Most of us do not know how to use coal economically in
our homes, and thus aid not only in wasting the coal supplies but in
making the cost of living higher than it should be. All together, in the
handling of coal we lose fully half of it. The coal supply of the earth
is disappearing very fast, and at the rate at which its use is now
increasing it may not last more than one hundred years.

If we cannot use coal without wasting so much, would it not be wiser for
us to turn our attention more fully to the sources of power in the
streams which are flowing down all our mountain sides? The use of this
power when turned into electricity would enable us to save a large part
of the coal, oil, and gas that are now used, and so make them last
longer.

It is far easier to waste oil and gas than coal, for, when we have
drilled holes in the earth, unless we are very careful the gas will
escape into the air and the oil will become mixed with water, so that it
will be difficult for us to get it.

Oil and gas are confined under great pressure hundreds and often
thousands of feet below the surface. To make clear how easy it is to
waste them, we might compare them to the compressed air in an
automobile tire. If the tire is punctured by a nail, the air issues
suddenly with a sharp, whistling sound until the pressure inside is gone
and no more will come out.

For many years we have been puncturing the crust of the earth, where oil
has been discovered, and letting the oil and gas escape. We have saved
most of the oil, but nearly all the gas has been wasted. The gas will
finally stop coming out when the pressure is gone, just as the air did
in the automobile tire.

On the opposite page is a picture of a "gusher" in the Sunset oil field,
California, which tells the story of how we are permitting the valuable
substances within the earth to be wasted. In drilling this well the oil
men suddenly struck a deposit of oil and gas under