Popular Science Monthly/Volume 7
DR. WILLIAM WHEWELL
THE
POPULAR SCIENCE
MONTHLY.
CONDUCTED BY E. L. Youman.
VOL. VII.
MAY, 1875, TO OCTOBER, 1875.
NEW YORK:
D. APPLETON AND COMPANY,
549 & 551 Broadway
1875.
Entered, according to Act of Congress, in the year 1875,
By D. APPLETON & CO.
In the Office of the Librarian of Congress, at Washington.