ASTRONOMY WITH AN OPERA-GLASS. 751 



soon as tbe glass is turned upon them. Castor is white, with occa- 

 sionally, perhaps, a suspicion of a green ray in its light. Pollux is 

 deep yellow. Castor is a celebrated double star, but its components 

 are far too close to be separated with an opera-glass, or even the most 

 powerful field-glass. You will be at once interested by the singular 

 cortege of small stars by which both Castor and Pollux are surrounded. 

 These little attendant stars, for such they seem, are arrayed in sym- 

 metrical groups — pairs, triangles, and other figures — which, it seems 

 difficult to believe, could be un- 

 intentional, although it would 

 be still more difficult to suggest 

 any reason why they should be 

 arranged in that way. 



Our little map of Gemini will 

 show you the position of the prin- 

 cipal stars of the constellation. 

 Castor and Pollux are in the 

 heads of the Twins, while the 

 row of stars marked in the map 

 Zi (£), Gamma (y), Nu (v), Mu 

 (/a), and Eta (17), marks their 

 feet, which are dipped in the 

 edge of the Milky-Way. One 

 can spend a profitable and pleas- 

 urable half-hour in exploring the wonders of Gemini. The whole 

 constellation, from head to foot, is gemmed with stars which escape 

 the naked eye, but it sparkles like a bead-spangled garment when 

 viewed with the glass. Owing to the presence of the Milky-Way, the 

 spectacle around the feet of the Twins is particularly magnificent. 

 And here the possessor of a good opera-glass can get a fine view of a 

 celebrated star-cluster known in the catalogues as 35 M. It is situated 

 a little distance northwest of the star Eta, and is visible to the naked 

 eye, on a clear, moonless night, as a nebulous speck. With a good 

 glass you will see two wonderful streams of little stars starting, one 

 from Eta and the other from Mu, and running parallel toward the 

 northwest ; 35 M is situated between these star-streams. The stars 

 in the cluster are so closely aggregated that you will be able to clearly 

 separate only the outlying ones. The general aspect is like that of a 

 piece of frosted silver over w T hich a twinkling light is playing. A 

 field-glass will bring out more of the component stars. The splendor 

 of this starry congregation, viewed with a powerful telescope, may be 

 guessed at from Admiral Smyth's picturesque description : " It pre- 

 sents a gorgeous field of stars, from the ninth to the sixteenth magni- 

 tude, but with the center of the mass less rich than the rest. From the 

 small stars being inclined to form curves of three or four, and often 

 with a large one at the root of the curve, it somewhat reminds one of 



Gemini 



