INTRODUCTION TO THE 

 From circumpolar stars. 



As these are wholly independent of tabular places, preference is given to the latitude resulting 

 from them, though differing in excess from the determination by quick moving stars more than 

 half a second of arc. Combining the four partial determinations of circumpolar stars by 

 weights derived from the sum of the numbers of observations at each culmination by their 

 product, the adopted latitude is 



33 26'25".89, 



and comparing each of the observations with this, the probable error, by the method of least 

 squares is 0".0866. 



The equatorial is 53$ feet to the south of the meridian circle. 



LONGITUDE. 



The longitude of the circle computed by Mr. S. L. Phelps, from moon culminations and 

 occultations observed during the same period is as follows,* the corrections to the moon's tabular 

 place, referred to in both series, having been computed by the methods given by Professor Benj. 

 Pierce in the Annual Report on the progress of the United States Coast Survey for 1854, pp. 

 115*-*120. 



The equatorial is 16 feet to the west of the meridian circle. 



Longitude from corresponding moon culminations. 



A public acknowledgment igdue to the Astronomer Royal, Q. B Airy, onq.; Professor Clmllis, Cambridge, (England :) 

 M. J. Johnson, eq., RadcllfTc astronomer, and Profcsaors Bochc and Bond for their prompt courtesy in communicating 

 observation* of moon culminatioim in advance of publir.itiuM, ami to l.i.-ut, nant M. F. Maury, Superintendent United States 

 Naval Obncrvatory, for the apparent places of the group of stars preceding \ " Orionia, which Mr. James Ferguson deter- 

 mined by mlcromctrlcal dlfferentiationn with the latter filar. 



