426 
Kometen. 
1828 : 
Mean time Bremen 
Appar. _/R 
Appar. 
Déclin. 
Nov. 
3. 
12 h 
8' 
— 
343° 
7' 
44" 
+ 
24° 
10' 
6' 
55 
4. 
12 h 
ir 
— 
CO 
J—a 
O 
57' 
52" 
+ 
23° 
45' 
17' 
55 
5. 
ll u 
40' 
— 
340° 
46' 
52" 
+ 
23° 
20' 
33' 
55 
9. 
ID 
13' 
59" 
336° 
5' 
54" 
+ 
21° 
29' 
19' 
55 
10. 
ID 
38' 
50" 
334° 
55' 
16" 
+ 
20° 
58' 
2' 
55 
25. 
7 h 
23' 
20" 
319° 
27' 
4" 
+ 
12° 
48' 
35' 1 
55 
27. 
7 h 
16' 
8" 
317° 
32' 
2" 
— 
— 
— 
Dec. 
1. 
7 h 
11' 
17" 
313° 
45' 
3" 
+ 
9° 
16' 
31' 
55 
1. 
8 h 
36' 
21" 
313° 
41' 
35" 
— 
— 
— 
55 
6. 
6* 
28' 
14" 
308° 
56' 
36" 
+ 
6° 
10' 
9' 
55 
9. 
6 b 
7' 
48" 
305° 
54' 
59" 
+ 
4° 
10' 
14' 
55 
10. 
6* 
35' 
19" 
304° 
51' 
21" 
“T 
3° 
28' 
13' 
55 
15. 
5 h 
38' 
44" 
299° 
17' 
2" 
— 
0° 
14' 
15' 
The first observations owing to the faintness of the comet, are 
uncertain. The comet was a very diffuse and feeble nebula, whose 
middle it was difficult to estimate with any certainty; after the end 
of November it was easier to observe. I purposely used, for these 
observations, the same telescope and magnifying power with which I 
observed it in 1795, 1805 and 1825, that I might, as far as recollection 
would enable me, assure myself whether, in the thirty-three years past, 
it had undergone any change of appearance not dependent on its difference 
of situation with respect to the sun und earth; but the bad weather, 
and a sky scarcely ever free from haze, prevented my forming any 
tolerable judgment on this point. In the year 1805 only did I see 
any tail distinctly to this comet; this time, and in 1795, I could perceive 
no trace of any. Perhaps however, after the 10 th December, when it 
approached its perihelion, it may have exhibited a tail, and I am very 
desirous to get information on that point. On the 15 th , when I last saw 
it, it was very hazy. 
This appearance of the comet has, it seems to me, established two 
important points: 1 st , That it has no light of its own, and shines only 
by the reflection of that of the sun; 2 al 9 That this comet actually does 
suffer a resistance in that part of space wherein it moves. 1 ) The Ephe 
meris of Encke, calculated on the hypothesis of such resistance, indi 
cates only a small and nearly constant error, giving the AH only about 
2' or 3', and the declination 1' too small: On the other hand, that of 
Damoiseatt, who supposes no resistance, gave a very variable error, 
which, after the middle of November, increased to an uncommon extent. 9 
9 Vergl. Astronomisches Jahrbuch fur 1826, S. 133 f., wo Encke diese von 
Olbers schoii damals ausgesprochene Ansicht weiter ausflihrt. Sch.