Front matter
Reading edition
BY
SAMUEL PIERPONT LANGLEY, Ph.D., LL.D.
DIRECTOR OF THE ALLEGHENY OBSERVATORY, MEMBER NATIONAL ACADEMY, FELLOW ROYAL ASTRONOMICAL SOCIETY, ETC., ETC.
Illustrated
BOSTON. TICKNOR AND COMPANY 211 Tremont Street 1888
Copyright, 1884, 1885, 1886, and 1887, by the Century Co.; and 1887, by S. P. Langley.
All rights reserved.
University Press: John Wilson and Son, Cambridge.