so 
MR. RUMKER’S OBSERVATIONS 
truth than that of the transit observations : it must be recollected at the same 
time that /3 Hydri is within 12° of the Pole, and all the other stars are circum- 
polar with the exception of Canopus. 
Besides the times of the equinoxes, equal altitudes of various stars were 
observed during their conjunction and opposition with the sun, and thus the 
right ascensions of the following stars have been established. 
Stars. 
Mean /R begin- 
ning of 1828 . 
Annual 
Variat. 
Number of Observations*'. 
/3 Hydri 
a Eridani 
Canopus 
(S Argus 
/3 Crucis 
2 a Centau. 
° 4 8 30.6 
22 49 26.13 
95 2 1.9 
137 48 59.36 
189 26 1.3 
217 0 2.8 
39-09 
33.428 
19.81 
10.908 
51.296 
66.856 
27 Set of equal Altitudes 
31 
22 
13 
30 
20 
Each set of equal altitudes comprehends from 20 to 50 observations on each 
side of the meridian. A set of absolute altitudes has been counted for half a 
set of equal altitudes. 
The above stars in their upper and lower culminations, form in different 
parts of the meridian so many meridian marks established without the assist- 
ance of the transit : thus it is not likely that the optical axis of this instrument 
could pass on the same day at the precise time through each of them, unless 
the plane in which it moves be that of the meridian. 
South Polar Distances of Circumpolar Stars deduced from their Superior 
and Inferior Culminations observed at Paramatta. 
The refractions and reductions for aberration, nutation and precession to 
the mean places in the beginning of 1828, have been computed for each ob- 
servation separately, and their mean has been applied to the mean of the mi- 
croscopes for upper and lower culminations. The half difference between the 
two thus corrected, gives the mean south polar distance for January 1, 1828. 
The half sum is the polar point, which will serve hereafter for the reduction 
of the remainder of the stars. 
* In determinations of positions of stars or of geographical places, the number and quality of ob- 
servations upon which they are founded should always be stated, in order that their due weight may 
be attached to them in comparisons with succeeding observations. 
