16 MR. RUMKER'S OBSERVATIONS 



Latitude. 



o / // 



Feb. 1823, Sirius. — Two observations mural circle 33 48 45.00 



', Canopus „ „ 50.74 



June 1826, |8 Centauri „ „ 49.75 



. , 2 « Centauri „ „ 51.15 



July 1826, 2 a Centauri „ „ 46.72 



March 1828, Canopus „ „ 52.20 



July 1828, /3 Crucis „ „ 47.73 



Mean of all the latitudes observed alternately direct and by reflection 33 48 49.1 



And assembling all the observations for the latitude, we find 



o / // 



With Repeating Circle, by repetitions on stars north and south of zenith 33 48 51.72 



Ditto without repetitions Ditto „ „ 48,55 



With Mural and Repeating Circle alternately direct and by reflection . . „ „ 49.10 



Latitude of the Observatory at Paramatta 33 48 49.79 



III. Longitude of the Observatory. 



The great distance of the meridian of the Observatory at Paramatta from 

 that of any other established Observatory, renders the determination of its 

 longitude more than usually difficult. Corresponding observations of occul- 

 tations and eclipses cannot be obtained, so that the longitudes deduced from 

 this kind of observations must depend upon the correctness of the lunar 

 tables, and must therefore deviate from the truth considerably more than they 

 would were they compared with corresponding observations. On the same 

 account the uncertainty of the moon's horary motion during intervals of 

 fifteen hours and upwards, must introduce inaccuracies in the longitudes de- 

 rived from the transits of the moon and stars in her parallel, even if compared 

 with corresponding observations made in Europe. 



The number of observations instituted for the longitude is, however, suffi- 

 ciently great to establish this point with nicety when they are all computed. 

 In a geographical view, the longitude of Paramatta and Sydney is well enough 

 known already; and in an astronomical view, the longitude is an object of 

 much less importance than the latitude. 



1. Lunar Observations. 

 The following distances of the sun from the moon wei-e observed by Sir 



