, [ - 475 ] 



LXVIII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from p. 399.] 

 February 15, 1866. — Lieut-General Sabine, President, in the Chair. 

 npHE following communication was read : — 

 -*- " Further Observations on the Spectra of some of the Nebulae, 

 with a Mode of determining the Brightness of these Bodies." By 

 William Huggins, F.R.S. 



. In the first part of this paper the author continues his observations 

 on the spectra of nebulae and clusters. The results already presented 

 by him to the Royal Society are confirmed by his new observations, 

 namely, that with his apparatus clusters and nebulae give either a 

 continuous spectrum or a spectrum consisting of one, two, or three 

 bright lines. The positions in the spectrum of these lines are the 

 same as those of the bright lines of the nebulae described in his former 

 papers. 



On account of the faintness of these objects the author was not 

 able to ascertain whether the continuous spectra which some of the 

 nebulae give are interrupted by dark lines in a manner similar to 

 the spectra of the sun and fixed stars. Some of these spectra appear 

 irregularly bright in some parts of the spectrum. 



The nebulae which follow have a spectrum of one, two, or three 

 bright lines ; in addition to which, in the case of some of them, a 

 faint continuous spectrum was visible. These bodies are probably 

 gaseous in constitution. 



No. 2102 .. 



. . 27 H. IV. 



No. 



4499 . 



... 38H.IV. 



4234 . . 



.. ! 52. 





4827 . 



... 705 H.I. 



4403 . . 



. . 17 M. 





4627 . 



. .. 192 H.I. 



4572 .. 



.. 16H.IV. 









The following 



nebulae and cluste 



rs give 



a continuous spectrum : — 



No. 105 .. 



18H.V. 



No. 



4315 



14 M. 



307 .. 



.. 151 H.I. 





4357 



... 190 II. II. 



575 .. 



.. 156 H.I. 





4437 



1 1 M. 



1949 .. 



81 M. 





4441 



... 47 H.I. 



1950 .. 



82 M. 





4473 



. . . Auw.N.44. 



3572 . . 



51 M. 





4485 



... 56 M. 



2841 . 



.. 43H.V. 





4586 



. . . 2081 h. 



3474 . . 



63 M. 





4625 



... 51 H.I. 



3636 .. 



3 M. 





4627 



... 192 H.I. 



4058 .. 



.. 215 H. I. 





4600 



15H.V. 



4159 .. 



.. 1945 7i. 





4760 



207H.II. 



4230 . . 



13 M. 





4815 



53 H. I. 



4238 . . 



12 M. 





4821 



... 233H.II. 



4244 . 



50H.IV. 





4879 



... 251 H.II. 



4256 . 



10 M. 





4883 



... 212 H.II. 



The second part of the paper contains an account of a mode of 

 determining approximatively the intrinsic brightness of some of the 

 nebulae. 



Analysis by the prisms shows that some of the nebulae consist 



