PLEASURES OF THE TELESCOPE. 515 



appearance, and had come to bear a close resemblance to that of 

 a planetary nebnla. This has been quoted as a possible instance 

 of a celestial collision through whose effects the solid colliding 

 masses were vaporized and expanded into a nebula. At present 

 the star is very faint and can only be seen with the most power- 

 ful telescopes. 



Underneath Cygnus we notice the small constellation Vulpe- 

 cula. It contains a few objects worthy of attention, the first being 

 the nebula 4532, the " dumb-bell nebula " of Lord Rosse. With 

 the four-inch, and better with the five-inch, we are able to per- 

 ceive that it consists of two close-lying tufts of misty light. 

 Many stars surround it, and large telescopes show them scattered 

 between the two main masses of the nebula. The star 11 points 

 out the place where a new star of the third magnitude appeared 

 in 1670. % 2695 is a close double, magnitudes six and eight, dis- 

 tance 1*4*, p. 82. 



We turn to map No. 18, and, beginning at the western end of 

 the constellation Aquarius, we find the variable T, which ranges 

 between magnitudes seven and thirteen in a period of about two 

 hundred and three days. Its near neighbor 2 2729 is a very close 

 double, beyond the separating power of our five-inch, the magni- 

 tudes being six and seven, distance 0'6", p. 176. 2 2745, also 

 known as 12 Aquarii, is a good double for the three-inch. Its 

 magnitudes are six and eight, distance 2*8", p. 190. In we dis- 

 cover a beauty. It is a slow binary of magnitudes four and five, 

 distance 3'3", p. 325. According to some observers both stars 

 have a greenish tinge. The star 41 is a wider double, magnitudes 

 six and eight, distance 5", p. 115, colors yellow and blue. The 

 uncommon stellar contrast of white with light garnet is exhibited 

 by t, magnitudes six and nine, distance 27", p. 115. Yellow and 

 blue occur again conspicuously in \f/, magnitudes four and a half 

 and eight and a half, distance 50", p. 310. Rose and emerald 

 have been recorded as the colors exhibited in 2 2998, whose mag- 

 nitudes are five and seven, distance 13"5", p. 346. 



The variables S and R are both red. The former ranges be- 

 tween magnitudes eight and twelve, period two hundred and 

 eighty days, and the latter between magnitudes six and eleven, 

 period about three hundred and ninety days. 



The nebula 4628 is Rosse's " Saturn nebula," so called because 

 with his great telescope it presented the appearance of a nebulous 

 model of the planet Saturn. With our five-inch we see it simply 

 as a planetary nebula. We may also glance at another nebula, 

 4678, which appears circular and is pinned with a little star at 

 the edge. 



The small constellation Equuleus contains a surprisingly large 

 number of interesting objects. 2 2735 is a rather close double, 



