AT THE OBSERVATORY AT PARAMATTA. 7 



If one of the stars has north declination, the formula is — ^ 1 ^ = la- 



titude. 



Thus in the mean of the zenith distances of 



a Ceti, Procyon, a Orionis, and Rigel z =35 48 59.56 Declinat, 5 = I b 14.3 N. 



and the zenith distance of /3 Argus, 6th Oct. 2' = 35 10 3.08 J' = 68 59 0.3 S. 



§(2 - 3') = 19 28.24 \{S' -S) -33 29 22.98 



i(2 — s') = 19 28.24 



Latitude = 33 48 51.22 



The mean of the zenith distances of the 



Tropic of Capricorn is z = 10 21 1.31 Obliquity J = 23 27 44.58 N. 



Zenith distance of Canopus a' = 18 47 7.61 Declinat. S' = 52 36 8.39 S. 



1(2' -s)= 4 13 3.15 i{S' + S) =38 156.48 



1(2—2) = 4 13 3.15 



Latitude = S3 48 53.33 



The zenith distance of the 



Tropic of Cancer is 2 =57 16 25.3 Obliquity J = 23 27 44.22 N. 



« Trianguli a' = 34 52 28.4 Declinat. S' = 68 41 33.44 S. 



i(2-2') = 11 11 58.4 l(S'-i) =22 36 54.61 

 Hence, Latitude 33 48 53.03 



If one of the stars is below the pole, and the other below the equator, the 

 formula becomes .... Colatitude = ^{z' — z) -{• |(5' + 5). 

 Thus the zenith distance of 



Tropic of Cancer 2 = 5°7 I'e 25.3 Obliquity S = 2'3 27 44^22 



|8 Argus, S. P. 2' = 77 11 58.2 Declinat. S' = 68 59 2.22 



1(2' -2)= 9 57 46.45 US' + S) =46 13 23.22 

 Hence, Latitude 33 48 50.33 

 The mean of the latitudes thus found is 33 48 52.0 



3. Latitude by Reichenbach's Circle without Repetitions. 



In the following observations, the level has been kept invariably in the same 

 position to the great circle, which has never been revolved about its axis. But 

 the circle has been alternately revolved 180° in azimuth, in order to observe 

 one and the same star on the meridian right and left of the division answering 

 to the zenith. The great circle being at the same time kept by means of the 



