30 
MR. RUMKER’S OBSERVATIONS 
ramatta and Sydney, the difference of longitude between both places was 
found 51 ".93. 
My calculation of the above solar eclipse observed by Sir Thomas Brisbane 
in Sydney, and myself at Paramatta, gives 
From Beginning. 
h m 
rri • . f Sydney 21 26 51.8 
rile conjunction at | p^ ran 4 tta . _ 21 25 55 . 32 
Hence Diff. of Long. 
End. 
h m s 
21 26 34.38 
21 25 42.40 
56.48 51.98 
But I believe we must reject the results from the beginning, and hold our- 
selves to that from the end 5P.98. 
Professor Wurm has computed my observations at Paramatta of the transit 
of Mercury over the sun’s disk 5th November 1822, as follows : 
Conjunction. 
Inner Contact, 
h m s 
Immersion 23 7 19.78 
Emersion 1 49 8.43 
Outer Contact. 
Immersion 23 4 39.20 
Emersion 1 52 6.92 
0 5 35.48 + 27-087 x. 
0 8 13.66 — 1 3.297 <r. 
0 6 32.82 + 25.944 x. 
0 8 10.02 — 1 2.953 x. 
Professor Wurm has also calculated the observations made of this pheno- 
menon by Sir Thomas Brisbane at Sydney, and has had the goodness to com- 
municate his calculation to me, viz. 
Conjunction. 
h m s h m s /7 
‘Immersion . . 23 8 6.28 0 6 52.20 + 27-068 x. 
Emersion. . . 1 50 1.83 0 9 3.42 — 13.286 x. 
Inner Contact, 
h m s 
23 8 6.28 
1 50 1.83 
Outer Contact. 
23 5 23.22 
1 53 0.34 
0 7 22.08 + 25.923 x. 
0 9 0.68 — 12.943 x. 
Sydney mean time^ 
Immersion . 
^Emersion . . 
Professor Wurm adds : 
“Thence follow immediately the differences of longitude between Sydney 
and Paramatta : 
Per Immersion. 
Per Emersion. 
-f 49.76 + 0.011 x. 
+ 50.66 + 0.010 x. 
By inner contact -f 49.30 — 0.024 x. 
By outer contact + 49.26 — 0.021 x. 
“ The mean of all four phases gives + 49 s .75, or that of the inner contact 
only (as the observation most to be depended on) + 49 s .53, which result 
cannot be materially altered by the small coefficient of x. I found, however, 
x = + 3\917- 
