GETTING ACQUAINTED WITH THE STARS 



pole. Paste a paper star around the umbrella rod where it passes 

 through the cover of the umbrella. As you look up into the 

 umbrella, you see this star where the North Star would be. Place 

 other paper stars in positions to represent the Big Dipper and one 

 or two other constellations. Make holes at the poles of a small 

 globe, place it on the umbrella rod so that it will rotate under the 

 umbrella. The North Star is now directly in line with the axis 

 of the earth represented by the rod of the umbrella. In place of 

 a globe, a ball, an apple, or an orange may be used. The latitude 

 of the place where you live equals the number of degrees it is north 

 of the equator. Mark the spot on the globe where you live. Now 

 imagine you are on the earth. Hold the umbrella still. Rotate 

 the globe and observe the direction in which you would look to see 

 the North Star at different times. Observe the direction in which 

 you see the end star in the Big Dipper. Rotate the globe from 

 west to east far enough to represent six hours' time, or one-fourth 

 of a revolution. Now observe the direction in which you would 

 look to see the same star. In what direction would the star appear 

 to have moved? 



Why Do Stars Rise and Set ? Suppose we are standing 

 at a certain place on the surface of the earth as it rotates 

 on its axis. After a complete revolution on its axis during 

 a period of 24 hours, we are brought back to the same 

 place. This turning as we look at the stars gives them 

 the appearance of rising and setting. If you walk up a 



Explain by means of this diagram why stars appear to rise and set. 



long hill behind which is a factory with a tall chimney, 

 the higher up the slope you go, the more you see of the 

 chimney. It appears to rise. If you go backwards down 

 the hill, you see the chimney gradually disappearing be- 



