On the Longitude of the Sydney Observatory. 
By Joun Trssvrt, F.R.AS. 
[Read before the Royal Society of N.S.W., 2 June, 1880.] 
In June, 1878, I had the pleasure of reading before a General 
Meeting of the Royal Society of N.S. W.a paper on a proposed correc- 
tion to the adopted longitude of the Sydney Observatory, and a 
days subsequently I contributed to the Astronomical Section a cores 
8 paper on the same subject. The correction to the longi 
e, 10h. 4m. 45-74s. E., was based on the longitude of my own 
Ohiversicat: derived from ten lunar occultations of stars and the 
m. 15-70s. E., its correction from the ten occultations 
+ 6°84s., the telegraphic difference of longitude + 1m. 28°83s., 
and the concluded longitude of the Sydney Observatory 10h. 4m. 
51:37s. E. East t longitude i is here supposed to be positive. The 
occultations were all disappearances at the moon’s dark limb, and 
e corrections of the moon’s places were derived from the pub- 
lished observations at Greenwich alone. Since 1878 I have been 
enabled to extend my investigation to thirteen additional occulta- 
tions, so that it now comprises altogether twenty-three occultation- 
phases, of which nineteen are disappearances at the dark, and four 
are reappearances at the © righ t, limb. For the occultations down 
to the close of 1875 the corrections of the Nautical Almanac 
io 
ree 25’ 53 0” a 99995576 will, therefore, represent respectively 
the g geocentric latitude and the log. — In 
the sxtjotned table will be found certain data employed in the 
