Established by Edward L. Youmans

APPLETONS’

POPULAR SCIENCE

MONTHLY

EDITED BY

WILLIAM JAY YOUMANS

VOL. LVI

NOVEMBER, 1899, TO APRIL, 1900

NEW YORK

D. APPLETON AND COMPANY

1900

COPYRIGHT, 1900,

BY D. APPLETON AND COMPANY.

APPLETONS’

POPULAR SCIENCE

MONTHLY.