THE UNIVERSE IN WHICH WE LIVE 19 



In latitudes such as those of mid-Illinois, Indiana, and Ohio, 

 or of Washington, B.C., or Denver, Colorado, all in the neigh- 

 borhood of 40 north latitude, the point directly overhead in 

 the celestial sphere, the zenith, is evidently 40 north of the 

 celestial Equator and 50 from the North (celestial) Pole. The 

 Pole is, in this latitude, about 40 above the horizon. There is, 

 therefore, a region of 40 around the Pole in which the stars never 

 set. There will be a broad band of sky running from 50 north 

 of the celestial Equator to 50 south that will be in part above the 

 horizon at any one time, and all of which may be seen by continu- 

 ous observation throughout the year or through any winter night. 



It is evident that the constellations seen, say, at midnight 

 on December 20 are not the same as those visible at the same hour 

 on June 20, for at the first of these dates the dark or night side 

 of the earth (Fig. 4, position c) is turned toward one part of 

 the starry vault, while at the other date it is turned toward the 

 opposite portion. Since the earth rotates on its axis, a person 

 at latitude 40 north will see all the stars pass in view that are 

 located north of 50 south celestial latitude. 



Probably the one constellation that everyone knows is the 

 "Big Dipper," seen in the latitude mentioned at any time of the 

 night, for it never sets but simply circles about the celestial Pole. 

 All the stars that make the Dipper are quite bright (see Fig. 7, 

 p. 20). The Dipper makes up part of the constellation known as 

 the Great Bear (Ursa Major). It is a curious fact that widely 

 separated ancient races like the Chaldeans (Abraham, it will be 

 remembered, came from Ur of the Chaldees) and the American 

 Indians called this star group by the same name, the Great Bear. 

 This is true of many constellations. They bear the same name 

 among Chaldeans, Chinese, Egyptians, Greeks, American Indians, 

 etc. It seems as if the name of many constellations must have 

 been given them before the races separated from that region that 

 was their common home. 



The two stars forming the side of the Dipper away from the 

 handle are commonly called the pointers, for if the line drawn 



