Transcriber's Notes:

1. Subscripts have been marked with an underscore character in front
with text surrounded in curly braces, for example: H_{2}O (formula
of water).

2. Inconsistent hyphenation of words preserved.

3. Several misprints fixed. A full list of corrections can be found at
the end of the text.



[Illustration: LIGHT AND LIBERTY]




The Century Books of Useful Science


ARTIFICIAL LIGHT

ITS INFLUENCE UPON CIVILIZATION

BY
M. LUCKIESH

DIRECTOR OF APPLIED SCIENCE. NELA RESEARCH LABORATORY,
NATIONAL LAMP WORKS OF GENERAL ELECTRIC COMPANY