PLEASURES OF THE TELESCOPE. 469 



also a double star ; unfortunately the companion, being of only 

 the tenth magnitude and distant less than 1" from its third-mag- 

 nitude primary, is beyond the reach of our telescopes. But rj points 

 the way to one of the finest star clusters in the sky, marked 13G0 

 on the map. The naked eye perceives that there is something 

 remarkable in that spot, the opera glass faintly reveals its distant 

 splendors, but the telescope fairly carries us into its presence. Its 

 stars are innumerable, varying from the ninth magnitude down- 

 ward to the last limit of visibility, and presenting a wonderful 

 array of curves which are highly interesting from the point of 

 view of the nebular origin of such clusters. Looking backward 

 in time, with that theory to guide us, we can see spiral lines of 

 nebulous mist occupying the space that now glitters with inter- 

 lacing rows of stars. It is certainly difficult to understand how 

 such lines of nebula could become knotted with the nuclei of 

 future stars, and then gradually be absorbed into those stars ; and 

 yet, if such a process does not occur, what is the meaning of that 

 narrow nebulous streak in the Pleiades along which five or six 

 stars are strung like beads on a string ? The surroundings of 

 this cluster, 1360, as one sweeps over them with the telescope 

 gradually drawing toward the nucleus, have often reminded me 

 of the approaches to such a city as London. Thicker and closer 

 the twinkling points become, until at last, as the observer's eye 

 follows the gorgeous lines of stars trending inward, he seems to 

 be entering the streets of a brilliantly lighted metropolis. 



Other objects in Gemini that we can ill miss are : /x,, double, 

 magnitudes three and eleven, distance 73", p. 70, colors yellow 

 and blue; 15, double, magnitudes six and eight, distance 33", 

 p. 205 ; y, remarkable for array of small stars near it ; 38, double, 

 magnitudes six and eight, distance 6'5", p. 162, colors yellow and 

 blue (very pretty) ; A, double, magnitudes four and eleven, dis- 

 tance 10", p. 30, color of larger star blue try with the five-inch ; 

 c, double, magnitudes three and nine, distance 110", p. 94. 



From Gemini we pass to Cancer. This constellation has no 

 large stars, but its great cluster Prsesepe (1681 on map No. 4) is 

 easily seen as a starry cloud with the naked eye. With the tele- 

 scope it presents the most brilliant appearance with a very low 

 power. It was one of the first objects that Galileo turned to when 

 he had completed his telescope, and he wonderingly counted its 

 stars, of which he enumerated thirty-six, and made a diagram 

 showing their positions. 



The most interesting star in Cancer is t, a celebrated triple. 

 The magnitudes of its components are six, seven, and seven and a 

 half ; distances 1", p. 35, and 5*5", p. 122. We must use our five- 

 inch glass in order satisfactorily to separate the two nearest stars. 

 The gravitational relationship of the three stars is very peculiar. 



