WITH A FOURTEEN FEET REFLECTOR. 



205 



Former Observations of these Nehulce. 



55. All the light which we can obtain on the past history of these nebulae 

 becomes of great moment in the inquiry, 'Whether their present form and 

 character are now sufficiently well determined to be a standard for the future?' 

 I have therefore collected into one group in order of time such scattered notices 

 of each as I have been able to find; the collection of which, as independent 

 observations, differing greatly in point of time, is of considerable interest in 

 detecting some important errors, and in ascertaining the probable stability of 

 the nebulae. And, furthermore, the distinguishing characteristics of that mode 

 of observing and describing the nebulae, which it is a chief object of this paper 

 to explain, will be more distinctly illustrated by a comparison of former with 

 the present observations. 



56. At the time of pursuing these inquiries with the 14 feet Reflector, the 

 great catalogue of Sir J. Herschel, (Phil. Trans. 1833,) was the only one with 

 which Mr. Smith and myself were acquainted; the common abridgment of the 

 Philosophical Transactions previous to 1800, contains of the elder Herschel's 

 catalogues, only a very full preface and explanation of the observations, with 

 the unfortunate omission, however, of the observations themselves, — an arrange- 

 ment not very well adapted to the convenience of future observers. Recently, 

 however, having access to the greater part of the original papers, I am enabled 

 to extract from them: 



H. v., 10, 11, 12; H. IV., 41; h. 1991.* 



40 of the 145; Sh. 379.t 



57. iStV ^Nilliam Herschel; First Catalogue of 1000. Phil. Trans. 1786, Part II. 



Cl. 



V. 



No. 



Date. 



star. 



Diff. of R. A. 



Diff. of Decl. 



No. of 

 Obg. 



Remarks. 



I 10 



July 12, 



1784. 



.5 (i) Sagittarii 



Foil. 



2m 4-25 



North 



0°49' 



1 



Three nebula, faintly joined, form a trian- 

 {Tle. In tiie middle (a) is a double star. 

 Very faint, and of great extent. 



* Synonyms of the nebula. 

 VII. 3 B 



t Synonyms of the triple star in its centre. 



