AND ITS INHABITANTS 155 



dependent upon the vegetation which feeds either them or 

 their prey. Vegetation Is absolutely dependent upon tempera- 

 ture, rainfall, winds, ocean currents, and other climatic con- 

 ditions. Soil, to be sure. Is of much Importance, but all soils 

 would be moderately fertile If they had never been subjected 

 to any except a favorable climate. There would be no great 

 wastes of sand, salt, gravel, or naked rock, for these arise 

 only under aridity, glaclatlon, high wind, or other extremes. 



In spite of the overwhelming preponderance of climate In 

 determining the nature of material resources, certain articles, 

 such as Iron and coal, occur with little reference to heat or cold, 

 moisture or drought. Their use, however, depends largely 

 upon climatic conditions. Iron was well known in Mediter- 

 ranean lands at the time of their highest civilization. Never- 

 theless, Its use was strictly limited by the scarcity of fuel In a 

 subtropical climate. Only when iron was smelted In countries 

 like England where the climate fostered dense forests did its 

 use increase rapidly. When the value of coal was at last 

 realized It added wonderfully to man's material resources. 

 Yet even here the limitations of climate are strict. In Alaska 

 today the presence of coal does little to advance civilization. 

 It brings a group of coal miners whose chief desire is to make 

 money enough to enable them to get home again. Because 

 Alaska Is so cold and inhospitable the regions with better 

 climates farther south are the ones that profit by Its coal. So, 

 too, with the iron mines of Gelllvara in northern Sweden. A 

 few small towns have sprung up, but the places chiefly benefited 

 are the cities of southern Sweden where the climate Is less 

 severe. Thus it appears that all kinds of resources are strictly 

 limited by climate either In their occurrence or in their use. 



Energy, The importance of energy In advancing civiliza- 

 tion is not so well understood as that of Inherent mental 

 capacity and material resources. Darwin says that the latent 

 capacities with which most men are endowed are so great 



