MK. W. HUGGINS ON THE SPECTRA OF SOME OF THE KBBULiB, 397 



Measures of this nebula by former observers — 



1833, diam. = 8 Sir John Heeschel*. 



1856, March, diam. = 6 D'Akrest| 

 1856, June, diam. = 8 D'Abbest) 



1864, August, diam. = 9-6 Schultz 

 =14-5 AuwERsI 



}t 



Nebula No. 4514. 2050 h. 73 H. IV. I made careful measures of this object on two 

 occasions. Wire micrometer with dark ground illumination. 

 1865. Nov. 25. Power 333. Mean of six measures 31"-06. 

 1865. Dec. 15. Power 680. Mean of three measures 30"-66. 



I think the measures of Dec. 15 are entitled to more confidence than those of Nov. 25. 

 I should prefer to take as the most probable value — Diam. in K.A. =30"-8. 



1833. Diam. in R. A. =45" -5. Sir John Herschel§. 

 1864. Diam. inR.A.= 0'-4. Schultz ||. 



* Philosophical Transactions, 1833, p. 458. 



t Beobachtungen der Nebelflecken und Sternhanfen, p. 341. 



X Astronom. Nachrichten, No. 1541, p. 70. § Philosophical Transactions, 1833, p. 464. 



II Astronom. Nachrichten, No. 1541. 



MDCCCLXVI. 3 I 



