204 



THE POPULAR SCIENCE MONTHLY. 



orange and green, very distinct. Variability has been ascribed to 

 each of the stars in turn. It is not known that they constitute a 

 binary system, because no certain evidence of motion has been ob- 



Map No. 15. 



tained. Another very beautiful and easily separated double is 8, 

 magnitudes three and eight, distance 10", p. 175, colors pale green 

 and purple. 



