272 ELEMENTS OF GENERAL SCIENCE 



a way that the whole dipper seems to revolve with the han- 

 dle turning on the dipper point as an axis. The Big Dipper 

 is a part of the larger constellation known as Ursa Major, or 

 the Great Bear, referred to later. If a line is drawn through 

 the two stars of the part of the bowl opposite the handle, 

 and this line is extended above the bowl a distance about 

 six times the distance between the two stars, this line will 

 lead to a star of similar size and clearness, the North Star, 

 or Pole Star. The two stars are known as the " pointers." 

 For unknown ages the Big Dipper and the Pole Star have 

 been used as guides by travelers in the night. 



If in the month of November, about eight o'clock at night, 

 the observer faces the north, he will find above the Pole Star, 

 about three fourths of the distance from the north horizon 

 to a point directly overhead, a zigzag of seven stars of the 

 second and third magnitudes which constitutes the constella- 

 tion Cassiopeia, known as " the woman in the chair." To most 

 people it does not look like a chair, but like the letter W. 

 The bright star which forms the bottom of the right-hand 

 half of the W is a " double star," as is also the one near 

 the middle of the third stroke of the W. The double 

 nature of these stars cannot be determined except by use of 

 a telescope, but it is interesting to know that in the second 

 case the two suns revolve around their common center in 

 a period of about two hundred years. At the time when 

 Cassiopeia is visible, as indicated above, the Big Dipper is 

 directly under the pole and so near the horizon that it 

 cannot be observed unless the sky is very clear. 



If the observer faces the south, and looks a little to the 

 west of the south point and up about two thirds of the way 

 between the horizon and the zenith, he will see the constel- 

 lation Pegasus, which can be recognized from the fact that 

 in it there are four stars which form a large square known 

 as the " Great Square of Pegasus." There are no other con- 

 spicuous stars in this region of the sky. 



