PLEASURES OF THE TELESCOPE. 797 



We come now to Ursa Major's principal attraction , frequent- 

 ly called Mizar. The naked eye perceives near it a smaller star, 

 called Alcor. With the three-inch glass and a medium power we 

 divide Mizar into two bright stars brilliantly contrasted in color, 

 the larger being white and the smaller blue-green. Beside Alcor, 

 several fainter stars are seen scattered over the field of view, and, 

 taken all in all, there are very few equally beautiful sights in the 

 starry heavens. The magnitudes of the double are three and 

 four, distance 14*5", p. 148. The large star is again double, al- 

 though no telescope has been able to show it so, its duplicity 

 being revealed, like that of /3 Aurigse, by the periodical splitting 

 of the lines in its spectrum. 



Ursa Major contains several nebulee which may be glimpsed 

 with telescopes of moderate dimensions. An interesting pair of 

 these objects, both of which are included in one field of view, is 

 formed by 1949 and 1950. The first named is the brighter of the 

 two, its nucleus resembling a faint star. The nebula 2343 pre- 

 sents itself to us in the form of a faint, hazy star, but with large 

 telescopes its appearance is very singular. According to a pic- 

 ture made by Lord Rosse, it bears no little resemblance to a skull, 

 there being two symmetrically placed holes in it, each of which 

 contains a star. 



The portion of Canes Venatici, represented in map No. 26, con- 

 tains two or three remarkable objects. 2 1606 is a close double, 

 magnitudes six and seven, distance 1", p. 336. It is a pretty sight 

 with the five- inch. The double star 2 is singular in that its larger 

 component is red and its smaller blue ; magnitudes six and eight, 

 distance 11 '4", p. 260^ Still more beautiful is 12, commonly 

 called Cor Caroli. This double is wide, and requires but a slight 

 magnifying power. The magnitudes are three and six, distance 

 20", colors white or light yellow and blue. The nebula 3572, 

 although we can see it only as a pair of misty specks, is in reality 

 a very wonderful object. Lord Rosse's telescope has revealed in 

 it a complicated spiral structure, recalling the photographs of the 

 Andromeda nebula, and indicating that stupendous changes must 

 be in process within it, although our records of observation are 

 necessarily too brief to bring out any perceptible alteration of 

 figure. It would seem that the astronomer has, of all men, the 

 best reasons for complaining of the brevity of human life. 



Lastly, we turn to Ursa Minor and the Pole Star. The latter 

 is a celebrated double, not difficult, except with a telescope of less 

 than three inches aperture in the hands of an inexperienced ob- 

 server. The magnitudes are two and nine, distance 18*5". The 

 small star has a dull blue color. In *' we discover a wide double, 

 magnitudes six and seven, distance 30", p. 83. 



This completes our survey of the starry heavens. 



