Transcriber's Notes:

  1. Inconsistent hyphenation of words preserved.
  2. Several misprints corrected. Hover over underlined word in the text to see the corrections made. A full list of corrections can be found at [the end] of the text.
  3. On [page 19], Aristophanes's period is noted as (488-385 B. C.); Aristophanes was born circa 448 B. C.

LIGHT AND LIBERTY

The Century Books of Useful Science

Artificial Light