SMITHSONIAN MISCELLANEOUS COLLECTIONS 
VOLUME 134, NUMBER 1 
Roebling Fund 
PERIODS RELATED TO 273 MONTHS 
OR 22-3/4 YEARS 
By ' 
C. G. ABBOT 
Research Associate, Smithsonian Institution 
H 
eneee 
Pre 
(PuBLicaTION 4265) 
CITY OF WASHINGTON 
PUBLISHED BY THE SMITHSONIAN INSTITUTION 
SEPTEMBER 13, 1956 
