LATITUDE OF THE SYDNEY OBSEKVATORY. 93 



LATITUDE OF the SYDNEY OBSERVATORY. 



By 0. J. Merfield, f.r.a.s., 



Mitgliecle.r der Astronomischen Gesellschaft. 



[Read before the Royal Society of N. S. Wales, December 6, 1905.2 



1. Introduction. 



2. Observation and Methods. 



3. Details of Results and the final deductions. 



4. Conclusion. 



This forms an appendix to a paper 1 on the " Provisional 

 Determination of Astronomical Refraction, from observa- 

 tions made with the Meridian Circle Instrument of the 

 Sydney Observatory." 



1. Introduction. 

 The adopted latitude of the Sydney " Meridian Circle 

 Instrument " is 



4> = -33° 51'41-'l 

 and this valae has been used for many years — since 1860 — 

 in all reductions of observations made at the Observatory. 

 The above value of the latitude was determined by the 

 Rev. W. Scott, m.a., 2 with a transit instrument, during the 

 month of June 1859. The method used in the investigation, 

 was to observe the zenith distance of a star, and after 

 correcting the observation for refraction, this distance was 

 added to or subtracted from its tabular north polar dis- 

 tance, according as it was north or south of the zenith; the 

 result diminished by 90 degrees, represented the numerical 

 value of the observed latitude. 



1 This Journal, Vol. xxxix., p. 76. 



2 The Government Astronomer for New South Wales during the years 

 1856-62. 



