7 88 THE POPULAR SCIENCE MONTHLY. 



awakens a lively appreciation of the vast differences of magni- 

 tude that exist among the different snns of space. 



The actual size and might of this great red sun form an at- 

 tractive subject for contemplation. As it appears to our eyes 

 Aldebaran gives one twenty-five-thousand-millionth as much 

 light as the sun, but if we were placed midway between them the 

 star would outshine the sun in the ratio of not less than 160 to 1. 

 And yet, gigantic as it is, Aldebaran is possibly a pygmy in com- 

 parison with Arcturus, whose probable dimensions were discussed 

 in the chapter relating to Bootes. Although Aldebaran is known 

 to possess several of the metallic elements that exist in the sun, 

 its spectrum differs widely from the solar spectrum in some re- 

 spects, and more closely resembles that of Arcturus. 



Other interesting objects in Taurus are o-, divisible with the 

 naked eye, magnitudes five and five and a half, distance 7' ; 2 674 

 double, magnitudes six and nine, distance 10'5", p. 147 ; 2 716, 

 double, magnitudes six and seven, distance 5", p. 200, a pleasing 

 sight ; t, triple, magnitudes four, ten and a half, and eleven, dis- 

 tances 36", p. 249, and 36', p. 60. The ten-and-a-half-magnitude 

 star is itself double, as discovered by Burnham ; star cluster No. 

 1030, not quite as broad as the moon, and containing some stars as 

 large as the eleventh magnitude; and nebula No. 1157, the so- 

 called " Crab nebula " of Lord Rosse, which our glasses will show 

 only as a misty patch of faint light, although large telescopes 

 reveal in it a very curious structure. 



We now turn to the cluster of circumpolar constellations some- 

 times called the Royal Family, in allusion to the well-known story 

 of the Ethiopian king Cepheus and his queen Cassiopeia, whose 

 daughter Andromeda was exposed on the seashore to be devoured 

 by a monster, but who was saved by the hero Perseus. All these 

 mythologic personages are represented in the constellations that 

 we are about to study. We begin with Andromeda (map. No. 24). 

 The leading star a marks one corner of the great square of Pega- 

 sus. The first star of telescopic interest that we find in Andromeda 

 is /*, a double difficult on account of the faintness of the smaller 

 component. The magnitudes are four and eleven, distance 49", 

 p. 110. A few degrees north of /* the naked eye detects a glim- 

 mering point where lies the Great Nebula in Andromeda. This 

 is indicated on the map by the number 116. With either of our 

 three telescopes it is an interesting object, but of course it is ad- 

 visable to use our largest glass in order to get as much light as 

 possible. All that we can see is a long, shuttle-shaped nebulous 

 object, having a brighter point near the center. Many stars are 

 scattered over the field in its neighborhood, but the nebula itself, 

 although its spectrum is peculiar in resembling that of a faint 

 star, is evidently a gaseous or at any rate a meteoritic mass, since 



