84 THE NEBULA IN ANDROMEDA. 



No. 8 of the same catalogue lies so near to the southern boun- 

 dary of the nebula, that, according to the dimensions assigned to it, 

 it should also be considered as connected. 



The most interesting feature of the nebula is the existence of 

 the dark bands or canals before referred to. That which is nearest 

 the nucleus is the longest and the most distinct. It commences 

 somewhat abruptly near a group of small stars, in A. R. 0'' 32"' 36' 

 and Dec. 40° 07' ; its breadth being about one minute and one half 

 of arc. For about half a degree, to A. R. 0" 34"- 10^, Dec. 

 40° 30', it is marked with great uniformity ; its sides being to all 

 appearance perfectly straight, suddenly terminated, and slightly 

 diverging. Soon after passing the parallel of the nucleus, it ap- 

 pears to bend towards the following side, becoming fainter and less 

 regular ; beyond the parallel of 40° 50' it can no longer be traced 

 with certainty. 



The second commences at a point a few minutes north-preced- 

 ing the first, and is there distant from it about four minutes of arc. 

 It closely resembles its companion, excepting that, as it occurs in 

 fainter light, it is less distinct, and is sooner lost after passing the 

 nucleus. 



The two are inclined to each other by an angle of about three 

 degrees, their distance apart increasing towards the north. Their 

 sides seem to have a common point of divergence. 



Sir John Herschel, in his catalogue of nebulae published in the 

 Philosophical Transactions for 1833, refers, with an expression of 

 astonishment, to a structure evidently analogous to that just de- 

 scribed, though on a scale greatly inferior, which occurs in h 1357 

 and 1376 ; engravings of both, faithfully representing the originals, 

 accompany the catalogue. It may be noticed that these three 

 most interesting objects lie almost precisely in a great circle of 

 right ascension, which intersects the milky way at right angles. 



