WITH A FOURTEEN FEET REFLECTOR. 



209 



observed in it are, 1st, the resolvable knot in the following portion of the bright branch, which is, in a 

 considerable degree, insulated from the surrounding nebula; strongly suggesting the idea of an absorption 

 of the nebulous matter' ; and, 2dly, the much feebler and smaller knot at the north preceding end of the 

 same branch, where the nebula makes a sudden bend at an acute angle m. With a view to a more exact 

 representation of this curious nebula, I have, at different times, taken micrometrical measures of the rela- 

 tive places of the stars in and near it", by which, when laid down as in a chart, its limits may be traced 

 and identified, as I hope soon to have better opportunity to do than its low situation in this latitude will 

 permit. 



V. 19; h. 2092 and 2093. 



59. Sir William Herschel. " On the Construction of the Heavens." Phil. Trans. 1785, Part I. 

 The 2d and 3d of the seven "very compound nebula;, or milky ways," which "cannot be otherwise 

 than of a wonderful magnitude, and may well outvie our milky way in grandeur,'" both belong to this 

 extensive nebula: 



The second" is an extremely faint milky ray, above ^ of a degree? long, and 8 or 10' broad p; extended 

 from north preceding to south following. It makes an angle of about 30 or 40 degrees with the meridian, 

 and contains three or four places that are brighter than the rest. The stars of the Galaxy are scattered 

 over it in the same manner as over the rest of the heavens. It follows « Cygni 11.5 minutes of time, and 

 is 2° 19' more south. 



The third'i is a branching nebulosity of about a degree and a half in right ascension, and about 48' ex- 

 tent in polar distance. The following part of it is divided into several streams, which, after separating, 

 meet each other again towards the south. It precedes ^ Cygni 16'n in time, and is 1° 16' more north. I 

 suppose this to be joined to the preceding one; but, having observed them in different sweeps, there was 

 no opportunity of tracing their connexion. 



Sir William Herschel; First Catalogue of 1000. Phil. Trans. 1786, Part II. 



CI. 



No. 



Date. 



Star. 



Difl\ of R. A. 



DifF. of Decl. 



No. of 

 Obs. 



Remarks. 



V. 



14 



Sept. 5, 



1784. 



52 (k) Cygni 



Foil. 



lira 24^ 



North 



0=44' 



2 



Branching nebulosity, extending in R. A. 

 near li", and in P. D. 52'. Tlie following 

 part divides into several streams, uniting 

 again towards the south,(r) 



Sir William Herschel. " Astronomical Observations relating to the Construction of the Heavens, ar- 

 ranged for the purpose of a critical examination, d^c." Phil. Trans. 1811, Part II. Under the first 

 of the many classes into which he had arranged them, we have: 



1. Of Extensive Diffused Nebulosity. 



The first article of my series will begin with extensive diffused nebulosity, which is a phenomenon that 



m Art. 47. 2; Art. 49. 4; Art. 50. 1. 



n In Sir J. Herschel's present drawing, the places of at least four or five stars seem to have been settled by 

 measurement. o Corresponding to h. 2092; Art. 64. 



p I should think over-estimated. q & r Corresponding to h. 2093; Art. G4. 



VII. — 3 c 



