CHAPTER IV 



THE EAETH'S OEUST 



36. Land and Water Areas. The surface of the earth has 

 an area of about 197,000,000 square miles, about 28 per 

 cent of which is land. Such areas are too vast for us to con- 

 ceive, but it may help us toward a conception to know that 

 the area of the United States, exclusive of Alaska arid islands 

 belonging to it, is about $ of the land area of the earth. 



It is possible to divide the surface of the globe into two 

 hemispheres, one of which contains the larger part of its 

 land and the other the larger part of its water surface. 



This bunching of the 

 land has brought the 

 people of the earth 

 near together and has 

 greatly facilitated 

 their intercourse, es- 

 pecially since land 



LAND AND WATER HEMISPHERES. transportation has be- 



come so easy. Under 

 the climatic condi- 

 tions which exist, it is very advantageous also for the in- 

 habitants of the earth that the greater part of the polar 

 lands are around the north pole instead of the south. The 

 fact that the land masses have irregular outlines and are 

 separated by water areas instead of being in one continuous 

 extent is also, as we shall see, of benefit to the earth's in- 

 habitants. 



37. Interchange of Land and Water Areas. It has been 

 found from numerous observations that the land and sea 



68 



Notice that London is about at the center of 

 the land hemisphere. 



