On the Great Comet of 1843. 
Date. 
B. Cc. 432 
A. D. 268 (?) 
442 (?) 
617 
968 
1143 (*) 
1317 
1493 
1668.2 (*) 
1843.2 
Date. 
B. c. 60 (*) 
A. p. 290 (*) 
639 (?) 
815 
990 ? 
1165 
1340 * 
1516? 
1689.95 (*) 
1865.04 
Periods of eight revolutions 
preceding the recent ap-|Single revolutions and mean 
pearance. 
13 175.00 
9X 175.02 
8X 175.15 
7X 175.17 
5X 175.04 
4X 175.05 
3X 175.40 
2X 175.10 
1X 175.00 
Periods of eight revolutions 
preceding expected return|Single revolutions and 
in 1865.04. 
11 175.00 
9X 175.00 
7X 175.14 
6X 174.99 
5X 174.99 
4X 175.23 
3X 174.98 
2% 174.47 
1X 175.00 
Date. 
B. c. 213 
A. D. 488 
837 
1012 (*) 
1362 (*) 
1537 (*) 
1886.91 
Periods of eight revolutions 
preceding expected return|Single revolutions and mean 
nol 
period. 
72 X21.878 
64 « 21.894 
56 X 21.896 
40 X 21.880 
32 21.881 
24 21.925 
16 X21.888 
8X 21.875 
88 & 21.875 
72X 21.875 
56 X 21.892 
48 x 21.874 
40 x 21.874 
32 & 21.904 
24 21.873 
16 21.809 
8X 21.875 
period. 
Rx 174.99 
8x 174.85 
6X 174.97 
5X 174.96 
3X 174.94 
2x 174.91 
96 X 21.874. 
64 21.856 
48 X 21.871 
40 21.870 
24 21.867 
16 21.864 
203 
104 21.876 
mean 
We have stated the opinion of several able astronomers, that 
the densest portion of the nebulosity of the recent comet (neces- 
sarily selected as the proper point for micrometric measures) was 
eccentric towards the sun from the real head or centre of gravity 
of the comet, tail and nebulous envelope. 
In fact the comet nev- 
er presented any appearance of a distinct kernel or head, but only 
a vague and ill-defined nebulosity or cloud, gradually condensed 
towards the centre, or, according to Messrs. Herrick and Bradley, 
towards a point nearer the sun than the centre of the disc (if we 
may so call it) of the nebulosity. In Prof. Bartlett’s letter, men- 
