ME. W. HUGGINS ON THE SPECTEA OF SOME OF THE NEBULA. 391 



[No. 4586. 2081 h. R.A. 20'> 27" 19»-8. N.P.D. 83° 3' 41"-3. Bright cluster.] 



Spectrum continuous. 



[No. 4625. 2097 h. 52 H. I. R.A. 20»' 54-" 43»-8. N.P.D. 74° 21' 5r-7. Bright; 

 pretty large ; round ; gradually brighter in the middle.] 



"Eound. Bright middle." — Lord RosSE*. 



Spectrum continuous. 



[No. 4600. 2088 h. 15 H. V. R.A. 20'' 39™ 53^ N.P.D. 59° 47' 14"-8. Pretty 

 bright ; k Cygni involved.] 



" It is very long and winding, and runs northward from k full 2 fields' breadth (30"). 

 The nebulosity is milky, and does not seem to arise from small stars in the Milky Way 

 ill seen." — Sir John HsRSCHELf . 



" This nebula resembles the Milky Way, and is full of dark uneven rifts or lanes. 

 There are portions of its preceding edge clearly resolvable." — Lord RossE J. 



I was not able to obtain a satisfactory spectrum of the nebula. The spectrum of the 

 involved star was carefully examined. No peculiarity was observed in the continuous 

 spectrum of the star. I have, however, the impression that the spectrum of the star, 

 from about F towards the more refrangible end, appeared bright relatively to the other 

 part. This might arise from groups of dark lines in the less refrangible portion of the 

 spectrum. 



[No. 4760. 2149 h. 207 H. IL R.A. 22'' 1™ 37^-4. N.P.D. 59° 20' 35"-6. Bright; 

 extremely resolvable.] 



" There is no doubt this nebula is a cluster." — Lord OxMANTOWisr. 



Spectrum continuous. 



[No. 4815. 2172 h. 53 H L R.A. 22'' 30'° 39'-5. N.P.D. 56° 20' 5" -6. Bright; 

 pretty large ; suddenly much brighter in the middle §.] 



" Stars sparkling near centre." — Lord Oxmantown. 



Spectrum continuous. 



[No. 4821. 2173 h. 233 H. IL R.A. 22'' 30'" 44^ N.P.D. 66°55'34"-6. Considerably 

 bright; small ; very suddenly much brighter in the middle, star 11th mag.] 



Spectrum continuous. 



[No. 4879. 2199 h. 251 H. IL R.A. 22'' 53-" 8«. N.P.D. 74° 46' 10". Pretty bright; 

 very gradually brighter in the middle.] 



Spectrum continuous. 



[No. 4883. 2201 h. 212 H. II. R.A. 22'' 54-" 1>Q. N.P.D. 60° 36' 32"-2. Consi- 

 derably bright ; gradually much brighter in the middle ; barely resolvable.] 



" Centre almost certainly resolvable." — Lord Oxmantown. 



The spectrum does not consist of one or two lines only. I believe that it is continuous. 



The discovery by means of prismatic observation, that some of the nebulae are gaseous 



* PhUosophical Transactions, 1861, p. 734. f Ibid. 1833, p. 468. J Ibid. 1861, p. 733. 



§ See drawing by Lord Eosse, Philosophical Transactions, 1861, Plate XXX. fig. 39. 



3h2 



