AT THE OBSERVATORY AT PARAMATTA. 
m 
1828. 
Nov. 28. — At l h 4 m 18 s the Comet followed a Star (y) in l s .8, being 30' 10" North thereof. 
The place of this Star according to Hist. Cel. is { Decl. 10° 51' 31". 
At l h 16 m the Comet preceded a star (z) 42% and another star (a) 56 s ; and was South of 
a, 22' 15". 
Dec. 5.— At l h l m 0 s the Comet followed a Star (/3) in l m 2% and was 5' 26" North thereof. 
At l h 31 ra 42 s , the Comet preceded 14 Delpliini 28 s . 12, and was 13' 50" South thereof. 
Fixed Stars. 
Determination of the Right Ascensions of some of the principal Stars of the 
Southern Hemisphere, by absolute, and equal Altitudes. 
1 . Absolute Altitudes. 
The weakness of the axis of the transit in Paramatta rendered it impossible 
for its optical axis to move in one and the same plane in passing from the 
north to the south of the zenith ; so that I could not place implicit confidence 
in the right ascensions of the southern stars deduced from the northern by 
means of this instrument. I was therefore desirous to establish the right 
ascensions of some of the principal southern circumpolar stars, independently 
of the transit, by methods not subject to any constant error, and I resorted first 
to repetitions with Reichenbach’s circle for observing the hour angles of these 
stars when near their greatest azimuth circle, corresponding to times of the 
sidereal clock, whereof the error was ascertained on the same days from equal 
altitudes of the Sun, Sirius, and other known stars. Not to lose the time de- 
voted at night to the transit and mural circle, I made these observations in the 
day-time, having constructed for that purpose a table of azimuths and altitudes 
for the star from 5 to 5 minutes, which enabled me to find the star at any time 
for the left observation ; and as the table contained also the double zenith 
distances, I had but to advance the nonius of the small circle by that quantity, 
in order to have the star again in the field after half a revolution in azimuth. 
Thus I could continue the repetitions to any extent with greater ease and 
accuracy in the day-time than at night. The observations were made as much 
as circumstances would admit east as well as west of the meridian, in order 
to let the errors of the instrument compensate each other. The observations 
were chiefly made at the time when the star’s azimuth was a maximum, and 
