180 OBSERVATIONS ON NEBULiE 



tain the fainter stars of the eleventh and twelfth magnitudes, where such were deemed de- 

 sirable. The nebula itself was decidedly fainter with 220 than with 80, and on this account, 

 as well as from its great extent, the nebula was examined and figured principally with the 

 lowest power. (These remarks apply also to the powers commonly used on the other 

 nebulae.) 



I think the nebula terminates near a pretty bright star (1 ;) I cannot certainly trace it far- 

 ther. Two bright stars of my first magnitude, or rather higher than any magnitude of my 

 scale, lie a little to the left hand of this extremity. Much of the nebula was roughly figured 

 last night; the figuring to-night completed in the network portion — also, in the faint band 

 down to the bifurcation. The character of this band seems to change as it approaches the 

 network, beginning to break up into windings and hollows, as if it partially partook of the 

 strange peculiarity of that portion in its approach thereto. The other end of the nebula 

 seems disposed, if I may so speak, to break up into rifts and branches nearly parallel, and is 

 certainly very different in its characteristics from the upper portion. 



Jiug. 1 9. — Nebula Cygni. Thirty or forty stars were added to the extreme lower por- 

 tion, of which not one-half are new. The description of the nebula by lines begun. I am 

 still uncertain about the three loops mentioned on the 9th. If they are as suspected, there is 

 reason to believe the same in many places all around. Indeed, the whole back-ground of 

 the heavens around the network, and in some places below, seems intersected with loops of 

 suspected nebulosity; it is certainly different in appearance from other portions of the hea- 

 vens. The loops and lace-work, which are certainly visible, probably fade off into such as 

 we cannot see, or, at least, can but suspect. 



I am not entirely certain of the subdivision into two of the larger bifurcate branch, first 

 noticed August 7th. With 220, two or three minute stars are set down in each of the sup- 

 posed branches, which certainly add to the effect, if they do not produce it. But, with con- 

 siderable attention, the division seems to exist above and below the place where these minute 

 stars are, the nebula between the two minor branches being not much inferior to either of 

 them in brightness. The other division, that of Herschel, is tolerably black, and very dis- 

 tinct. On the whole, I think the existence of a second division is confirmed. 



^ug. 20. — The description of the Nebula Cygni by lines completed. The stars in the 

 extreme lower part of this nebula are not so accurately placed as at the bifurcation and in the 

 network, nor do they descend to as definite and equal a limit in the scale of magnitudes. 

 But such care is obviously of less use in this lower diffuse part. 



The star (83,) at the bifurcation, was suspected to be a nucleus. With 220 it appears 

 somewhat blotty, and different from other equal stars in the vicinity. It is in the very 

 brightest portion of the nebula, at the principal bifurcation. With long attention, I am still 

 uncertain whether this be a nucleus or a kind of nebulous star. To determine this point 

 must require a telescope of greater light, or, at least, a better eye. Mr. Smith had no oppor- 

 tunity of examining this point. 



