"Mr. Williams has presented these scientific subjects to the popular mind with much clearness and force. It may be read with advantage by those without special scientific training."
RELIGIOUS TELESCOPE, Dayton, Ohio:
"It is historic, scientific, and racy. A book of intense practical thought, which one wishes to read carefully and then read again."
NEW YORK SCHOOL JOURNAL:
"A volume of handy science, not only interesting as an abstract subject, but valuable for its clear expositions of every-day science. Of Professor Williams as an authority upon such subjects, it is unnecessary to comment. He already has a fame as a scientific writer which needs no recommendation."
PALL MALL GAZETTE, London, England:
"Original and of scientific value."
GRAPHIC, London:
"Clear, simple, and profitable."
CANADA BAPTIST, Toronto: