312 PHYSICAL FEATURES OF THE UNITED STATES 



for the plow, so that it constitutes a great natural forest reserve, 

 needing only protection from fire to insure a perpetual supply 

 of timber. In the remainder of the province the rain tribute is 

 scant, falling far short of the farmer's needs, so that crops must be 

 irrigated. The downfall is greater on mountains than on valleys, 

 and about their cool summits the winter's snow lingers through 

 spring and summer, doling out water to mountain streams, which 

 may be utilized for the irrigation of valley lands. But the acres 

 which can thus be nourisht are only a small share of those whose 

 smooth surface invites the plow, and the valleys as a whole 

 belong to the herdsman rather than the husbandman. Their 

 grasses are scant, but this fault is half compensated by their im- 

 mense extent, and they must be counted as a valuable resource, 

 an important reserve of grazing land that can never be monopo- 

 lized by agriculture. On the higher plateaus and in the recesses 

 of the mountains are tracts and patches of forests, many of which 

 are protected against hasty consumption by inaccessibilit}', and 

 these supplement the great reserve of the extreme northwest. In 

 the mountains, also, are Plutonic stores of the precious and other 

 metals, and a score of valleys hold Apollonic magazines of coal. 

 The mountain streams, in addition to their tribute to agriculture, 

 afford power to the manufacturer. Untamed and fickle, subject 

 to enormous floods and irregular droughts, their control is not 

 easy; but if they shall ever be subdued and harnest, there is 

 hardly a limit to the tasks they may perform. 



The Central Plain, comprising half of all the land, has been 

 shaped by Apollonic forces. The geologist tells us of many up- 

 lifts, dislocations, and flexures of the crust; but all these have 

 been reduced to approximate evenness by the cooperative work 

 of rain, frost, and rivers. Where hollows were made they have 

 been filled ; \ where hills and mountains had grown they have 

 been pared away, so that only their roots, with a few low stumps, 

 remain. In types of detail there is much variety, and there are 

 many rugged tracts; but the characterizing feature is evenness, 

 and agriculture is the great industry for which the province is 

 naturally destined. 



On this broad fact, however, climate imposes an important 

 qualification. Over most of the province the spring and summer 

 rains suffice for the farmer's need, disappointing him only by 

 an occasional drought, but in a western belt following the base 

 of the Rock}'' mountains, and including much of the sub-province 

 known as the Great Plains, the rainfall is so scant that agricul- 



