308 Royal Society : — On the Spectra of Southern Nehulce. 



April 2. A pretty well defined and bright short line was dis- 

 tinctly visible in the spectroscope, accompanied by a considerably 

 fainter and more refrangible companion. Principal line measured 

 with the wires and found to be D + 2*l = 4-4 (6 = 3-97, F = 5'03), 

 i. e. 6 + 0-4. 



No. 4083. [M 15 h 12 m : N.P.D. 87° 25' : ! ! ; globular cluster, very 

 bright, large, extremely compressed in the middle.] 



April 5. Seen in telescope as a slightly oval nebulous ball, easily 

 seen but not very bright (perhaps owing to moon, nearly full) ; found 

 with some difficulty in spectroscope ; a faint continuous spectrum of 

 considerable width ; no trace or suspicion of lines. 



No. 4173. (Seen easily in telescope; but looked for in spectro- 

 scope for two hours in vain.) 



No. 4390. [M 18 h 6 m : N.P.D. 83° 10': planetary nebula ; very 

 bright, very small, little hazy.] 



April 6. Scarcely recognized as a nebula in the telescope. Seen in 

 spectroscope : a short bright line with a fainter one on the more 

 refrangible side, and a third strongly suspected. (Knowing so well 

 the relative positions of the "usual" lines, it is impossible that an 

 unprejudiced corroborative opinion can be offered on such slight 

 foundation as I have.) A very slight extension laterally was given 

 in this instance with the cylindrical lens. 



No. 2102. [M 10 b 18 m : N.P.D. 107° 59': !!; planetary nebula, 

 very bright, little extended.] 



April 9. Seen at once in telescope with low power ; and seen dis- 

 tinctly in the spectroscope as a bright and a faint line (the third 

 line not seen) ; principal line measured with the wires and found 



= D + j^jg = 2-15 j,or 6 + 0=48, F=6 + 1'06. 



D+ ^2-^ = 2-36 [=6 + 0-69, 



No. 1179. Nebula in Orion. Examined for comparison. The 

 spectrum of this nebula shows the three lines distinctly, and three 

 only ; they were measured (with the wires), and the results were : — 



"2-17 1 



D+ 1 2-20 = 2-19 I =6 + 0-52, 

 2-21 J 



and 



D+ 2-78 =6 + 1-11. 



The places and descriptions of the objects enclosed within brackets 

 are taken from Sir John Herschel's "General Catalogue of Nebulae " 

 in the Phil. Trans, for 1864. 



P.S. — The other day a storm passed over us. As there was agood 

 deal of lightning, I took the opportunity to examine its spectrum. 

 I saw, as I expected, numerous bright lines ; the blue nitrogen one, 



