738 EAEL OF EOSSE ON THE CONSTEUCTION OF SPECULA OF 6-FEET APEETUEE, 
List of Stars in the Dumb-bell Nebula, H. 2060, measured in autumns of 1850 and 
1851, Origin taken at a (a of M. Steuve) ; brightest star in sp. quarter. By 
Mr. Bindon Stoney. 
Name in 
observing- 
book. 
M. Struve’s 
name. 
X. 
Y. 
No. of 
observa- 
tion. 
X in 
M. Struve’s 
list. 
T in 
M. Struve’s 
list. 
t! 
// 
// 
/3 
d 
+ 154-4 
+ 17-5 
2 
+ 152-5 
+ 12-8 
c 
+ 325-3 
+ 63-1 
2 
-t- 321-1 
+ 62-8 
y 
e 
+ 172-8 
+ 98-6 
3 
172-5 
+ 98-8 
f 
+ 172-3 
+ 144-5 
2 
+ 174-6 
+ 142-2 
e 
9 
+ 173-9 
+ 193-2 
2 
+ 174-3 
+ 191-5 
9 
h 
+ 246-2 
+ 100-5 
2 
+ 251-1 
+ 101-7 
K 
k 
+ 187-4 
-121-3 
2 
+ 186-8 
— 121-0 
u 
w 
+ 323-5 
— 115-0 
2 
+ 317-7 
— 102-0 
0 
V 
+ 303-6 
+ 183-4 
2 
+ 308-3 
+ 186-3 
? 
h 
+ 23-0 
+ 199-7 
2 
+ 21-6 
+ 199-7 
tr 
0 
+ 46-8 
+ 149-5 
3 
+ 49-6 
+ 144-0 
TT 
P 
+ 48-1 
+ 61-3 
2 
+ 60-6 
+ 57-9 
r 
«' 
- 10-9 
- 59-8 
2 
— 12-3 
— 57-2 
i 
+ 235-8 
+ 70-8 
1 
+ 238-2 
+ 71-5 
‘ 
+ 223-0 
+ 51-4 
1 
! A 
+ 54-4 
- 22-8 
2 
1 X 
+ 304-6 
+ 21-3 
1 
; 
+ 73-6 
— 136-8 
1 
9 
+ 63-6 
— 122-6 
1 
w 
• • • 
+ 142-6 
+ 60-4 
1 
1 V 
r 
+ 398-2 
- 91-6 
1 
+ 396-9 
- 74-0 
A is the extremity of the bright mass of nebulosity in the sp. quarter. 
[Observations of Stars in the Dumb-bell Nebula, Messier 27, H. 2060. By M. O. Steuve. 
The following list of observations contains all stars which can be seen, by the Pulkova 
refractor, in the Dumbell Nebula. Sometimes I had a faint suspicion of some stars 
more visible on the ground of the nebula, but they were not seen distinctly enough to 
allow an exact micrometrical determination of their places. It will be interesting to 
see how many stars more Lord Kosse’s great reflector will show in this nebula ; from 
this comparison some approximate judgment might be formed about the respective 
space-penetrating powers of the two instruments. My observations extend as far as 1 
was able to trace the nebulosity, I think there is only one star in the lists situated 
quite out of the nebula. This star was observed merely for the sake of control. 
Probably Lord Posse’s large reflector will extend considerably further the boundaries of 
the nebulosity ; but to compare the relative powers of the two instruments, it will be 
necessary to confine the enumeration of the stars to the same boundaries which are 
approximately indicated by the stars in the following list. As fundamental point for 
the triangulation, I selected the star a of the 10th magnitude, situated near the S.W. 
corner of the nebula. It cannot be mistaken, for it is far the brightest object in the 
whole nebula. All observations have been made with illuminated wires in the dark 
field, and with a power of 207. 
