RELATION OF EARTH TO SUN AND MOON 



13 



HIGH TIDE IN NOVA SCOTIA. 



largely lacking, and we should have no tides strong enough 



to sweep clean our bays, removing the sewage, and to 



help vessels over the 



bars into some of our 



harbors. If the dis- 

 tance of the moon were 



changed, the height of 



the tides would be 



changed, and this would 



greatly affect our coast 



towns. 



Although we see the 



moon as a very bright 



object at night for a 



part of every month, yet 



it has no light of itself, 



and all the light it gives us is reflected from the sun. 



i i It has a rough, barren, 



rocky surface, full of 

 great crater-like depres- 

 sions. As far as known, 

 it has no air or water 

 upon it. As the earth 

 goes around the sun, 

 and the moon around 

 the earth, the position of 

 these three in relation 

 to each other is con- 

 stantly changing, and it 

 is these changes which 

 give us the varying 



Low TIDE AT THE SAME PLACE. 

 Showing the clean swept sea floor. 



heights of the tides and 



the different phases of the moon. It is profitable to try to 

 picture to oneself the changing phases of the moon. A 



