742 EAEL or EOSSE ON THE CONSTEHCTION OF SPECULA OF 6-FEET APEETUEE, 
To these relations must be added the mean value of the two observed relations N n 
(April 7, May 3) which gives N n ang. pos. =14° 51', distance =265"-65. 
These relations between the four principal objects form the base from which the 
places of the other stars are deduced by resolutions of the triangles formed by the 
observed directions. The following Table contains the results of my calculations. It 
gives the places of all observed objects with regard to N, the apparent centre of the 
greater nebula, and that of the star g to h. 
Ang. Pos. 
Distance. 
N n 
14 51 
265*65 
Na 
229 26 
88*57 
N6 
108 54 
243*63 
N J 
277 27 
121*9 
Ne 
161 47 
104*4 
N/ 
309 2 
189*9 
N A 
210 51 
174*2 
221 25 
202*6 
NA 
51 47 
115*1 
NZ 
54 48 
518*0 
N m 
190 24 
250*0 
hg 
267 5 
44*7 
Our observations contain several controls, by which it is proved that the deduced 
places of the stars, with regard to N, might be judged all exact within 2". This exact- 
ness must be regarded as very satisfactory, if we consider the extreme faintness of the 
observed objects. I estimate a star to be of the 14th magnitude if it is more suspected 
than distinctly seen in a dark night. Hence it follows that the greater part of the 
stars in our list are close to the extremity of measureableness in the Pulkova refractor. 
Another cause which troubles the agreement of results is the indistinctness of the 
centre of the greater nebula N. The centre of the small nebula n is much more 
distinct : all observations of the dimensions of the nebula, or of knots in it, have been 
omitted by me, as they can be observed with much more accuracy by Lord Posse’s 
powerful telescope. 
The Earl of Eosse communicated to me the following relations of sixteen objects in 
the nebula, as observed through his telescope. I add to that list the differences of our 
measures (S— E) for the objects which appear to be identical. 
