LATITUDE, AND OBSERVATIONS OF AZIMUTH. 



491 



The corrections for runs of the microscope-micrometers, for an arc of 100", 

 are as follows. They are the means of determinations at four or six different 

 parts of the circle. 



LATITUDE OF BURNHAM. 



Observations of zenith distance of 28 stars were taken with face of the 

 vertical circle alternately east and west, and all corrections proper for such 

 observations were applied. The North Polar Distances of the stars were 

 taken, as far as possible, from the Greenwich Catalogue of 2260 Stars for 

 1864. For stars near the South Pole the polar distances were taken from the 

 Cape Catalogue 1860, and the Melbourne Catalogue 1870. The results were 

 as follows : 



Co-latitude of Burnham 



o / // 



By 19 stars North of the Zenith 46. 23. I i'5g 



9 stars South of the Zenith 46. 23. 1 2'i5 



o / // 



Adopted Co-latitude .... 46. 23. 1 1 '9 



, , Latitude 43. 36. 48' i South. 



OBSERVATIONS OF AZIMUTH WITH THE ALTAZIMUTH. 



In making an observation, the instrument is clamped in azimuth, and the 

 zenith-distance slow-motion is used to make the transit of the object take 

 place over the middle of each vertical wire. The striding level is applied in 

 both positions to determine the error of level, after the four microscopes of 

 the horizontal circle have been read. The instrument is then reversed, 

 another transit observed in a similar manner, the circle read, and the level 



