calculating the horsepower of the
world, making us feel cheap in talking about our steam engines and
dynamos when a minutest fraction of the waste dynamic energy of the
solar system would make us all as rich as millionaires. But the heavenly
bodies are too big for us to utilize in this practical fashion.

And now the chemists have become as exasperating as the astronomers, for
they give us a glimpse of incalculable wealth in the meanest substance.
For wealth is measured by the available energy of the world, and if a
few ounces of anything would drive an engine or manufacture nitrogenous
fertilizer from the air all our troubles would be over. Kipling in his
sketch, "With the Night Mail," and Wells in his novel, "The World Set
Free," stretched their imaginations in trying to tell us what it would
mean to have command of this power, but they are a little hazy in their
descriptions of the machinery by which it is utilized. The atom is as
much beyond our reach as the moon. We cannot rob its vault of the
treasure.

READING REFERENCES

The foregoing pages will not have achieved their aim unless their
readers have become sufficiently interested in the developments of
industrial chemistry to desire to pursue the subject further in some of
its branches. Assuming such interest has been aroused, I am giving below
a few references to books and articles which may serve to set the reader
upon the right track for additional information. To follow the rapid
progress of applied science it is necessary to read continuously such
periodicals as the _Journal of Industrial and Engineering Chemistry_
(New York), _Metallurgical and Chemical Engineering_ (New York),
_Journal of the Society of Chemical Industry_ (London), _Chemical
Abstracts_ (published by the American Chemical Society, Easton, Pa.),
and the various journals devoted to special trades. The reader may need
to be reminded that the United States Government publishes for free
distribution or at low price annual volumes or special reports dealing
with science and industry. Among these may be mentioned "Yearbook of the
Department of Agriculture"; "Mineral Resources of the United States,"
published by the United States Geological Survey in two annual volumes,
Vol. I on the metals and Vol. II on the non-metals; the "Annual Report
of the Smithsonian Institution," containing selected articles on pure
and applied science; the daily "Commerce Reports" and special bulletins
of Depa