224 REPORTS FROM THE SECTIONS. 
i0h. 4m. 5108s. In 1873 fourteen comparisons were obtained, 
and the mean longitude derived was 10h. 4m. 51:07. In 1874 
irteen comparisons were obtained, and the mean tongivaall 
derived is 10h. 4m. 50°47. For abbeys years I have not yet 
received the moon observations from Greenwich. We have then, 
as the result of my own observations euanaial with correspond- 
ing observations at Greenwich— 
mm: 8 
1863 Ta 10 4 50°50 
1871 ms 50°91 
1872 51-08 
1873 51-07 
1874 50°47 
Givingamean 10 4 50.806 
which differs by 5-Ols. from that determined by the Rev. W. 
Scott, although the same instrument and method of observ ation 
were used by both of us ; and it is therefore obvious that between 
the Rev. W. Scott and myself there is a personal equation when 
observing the moon different from that between us when observing 
Just as has been found to be the case at Greenwich, the 
quantity is really a very small one—only 0°20—which produces 
this Sitloretins of 5s. in the longitude, and I am not surprised to 
oe it; forbetween us, when observing stars, there was a differen ce 
Tt must not, however, be sie ae that there is very great 
difficulty in determining t the moon’s position, and the observations 
made at Greenwich on all dead occasions for determining the 
question that extreme care is necessary in observing the moon. 
Now, turning to other sources for data upon the longitude of 
Sydney, we have first and most im important, the longitude of 
Melbourne ; this, Mr. Ellery has found from a large number of 
moon observations to be 9h. 39m. 54 ‘80s. ; a very careful deter- 
mination of the difference in longitude between the two observa- 
tions by means of the telegraph linee makes it 24m. 55:77s., and 
this added to 9h. 39m. 54-80s. givesus 10h. 4m. 50°57s. as the 
longitude of Sydney. 
In 1874, Major Palmer, while in New Zealand with the Transit 
of Venus ety found the longitude of ptt New 
Zealand, to be 1 lh. 39m. 481s. and as “the New 
the land lines at each end, so 
Sra nee a Was Pee 
