Work for the Telescope. 277 



A little to the E., somewhat N., of £, and consequently just 

 above it, as it declines towards the W.,* hes the famous cluster 

 Prcesepe, visible to the naked eye as a nebulous spot. It 

 scarcely comes within the scope of the present list, belonging 

 rather to the class of Groups and Clusters, of which it is one 

 of the most conspicuous. However, as we are so near to it, 

 we shall probably feel disinclined to let it pass. Our lowest 

 power will be required to enlarge the field, and comprehend at 

 once as much as we can of this magnificent cluster, which, 

 after all, will probably much exceed our limits. 



6. l Gancri. 30"" 1. 307 o, 8. 5i and 8. Pale orange and 

 clear blue. Herschel I. made the smaller deep garnet, 

 1782, February 8 • bluish, December 28; blue, 1785, March 

 12. Eelatively stationary, but there seems to be a common 

 motion in space. A beautifully-contrasted pair, hi which, as 

 usual, the hue of the larger component is taken from the less 

 refrangible end of the spectrum, an arrangement too general 

 not to indicate the footsteps of some unknown law. To find 

 it, a line is to be drawn from Prsesepe to Polaris, bearing a 

 little to the left ; where another line passing between Castor and 

 Pollux would intersect the first at right angles, we come upon 

 this star, which, though not bright, is the most conspicuous for 

 several degrees around. 



7. e Hydrce. 3"-4. 198°-4. (1837-11.) 3"'6. 203°-2. 

 (1843-14.) Fletcher, 208°-52. (1852-96.) 4and8|. Pale yellow 

 and purple. The small star in this beautiful object was missed 

 by Herschel I., and Dawes therefore suspects that it may be 

 variable. Struve discovered it, and his measure confirms the 

 idea that it may be in orbital motion, with a possible period of 

 450 years. It may be found thus : — a line drawn from Polaris 

 through Pollux, will fall upon Procyon, a 1st magnitude star 

 in Canis Minor. Another line carried from Procyon to 

 Eegulus passes just above a little group of stars, rather nearer 

 to Procyon of the two, marking the head of Hydra. The 

 most northerly of these is e. 



Here we suspend for the present our selected list of double 

 stars, proposing to resume it in our next number, together with 

 other matter of special interest during the month. 



* The student maybe reminded that N., S., E., and W. are always understood 

 a,s expressing the bearings of objects tvhen they are on the meridian, and that, in 

 proportion as they are removed from it, they cease to be synonymous with above, 

 belotv, to the left or right. 



VOL. I. — NO. IV. 



