year, and by even the best methods known a large proportion of the
heat units is wasted. Great effort should be made to improve the
locomotives so that they will consume less coal; but as long as the
railroad companies own the coal mines, as they do in many instances,
they can obtain coal so cheaply that the cost of the improved form of
engine is greater than the amount saved.

Another great use lies in the manufacture of coke, which is used in the
making of steel, and here, too, we see where great wastes have existed.
The old form of coke-oven was called the bee-hive on account of its
shape. These old style ovens consume all the coal with the exception of
the fixed carbon which is left behind as coke. At the prices which
prevailed in 1907, the value of the by-products wasted in bee-hive
coke-ovens was a little over $55,000,000--surely a loss worth
considering. A different form of coke-ovens is much used abroad and is
coming into use in this country. This is the retort or by-product oven,
sometimes called the recovery oven.

The bee-hive ovens are usually located near the mines where the cost of
coal is low, with small expense for transporting it. On the other hand,
the by-product ovens are established near the larger cities in order to
dispose of their gas and other by-products. Here the cost of
transportation must be added to that of the coal, but the products are
marketed near by instead of at a distance, as in the case of the
bee-hive ovens. The most improved by-product ovens produce not only coke
and gas, but coal-tar, pitch, ammonia, and creosoting oils, all
extremely valuable and adding greatly to the value of the output of the
ovens.

Electricity is another form of light and power which involves a large
waste of the energy of coal; only one-fifth of one per cent., that is,
one-five hundredth of the value of the coal is used in electricity, and
there is at present no known remedy for this.

There are methods, however, of lessening even this waste, and these are
constantly receiving more attention. One is for the electric plants
located in cities to sell their exhaust steam or water heated by the
coal as it is converted into electric power, as a by-product. The
electric power-house thus becomes a central heating plant to supply
stores, offices, and residences. Another system being tried abroad,
though scarcely past the experimental stage in this country, establishes
great electric power-houses at the coal min