Introduction ix 
precession in right ascension between 60 and 70 of declination, and precession in declination are 
derived from the tables given in Oeltzen's Argelander's Northern Zones (45 to 80). 
IN CONCLUSION 
I wish to express my obligations to Professor George E. Hale for his friendly interest in this 
work, and his valuable aid in bringing about its publication; to the officers of the Carnegie Institu- 
tion for their liberality in authorizing its presentation in printed form in the manner desired by the 
author; and to Professor Edwin B. Frost for his counsels and assistance during the prosecution of 
the observations at the Yerkes Observatory, and the passage of the manuscript through the press. 
S. W. BURNHAM. 
THE UNIVERSITY OF CHICAGO 
Yerkes Observatory, 
July, 1906. 
