342 GEOLOGY OF ILLINOIS. 



that by waiting a little later in the spring, the soil can then be worked, but 

 that gives so much the less time for the crop to ripen, add if the frost comes 

 early it is likely to be injured, if not entirely lost. By proper drainage this 

 would be, in a lara;e measure, remedied, the soil made warmer and more pro- 

 ductive, and the growing season rendered somewhat longer. In most places 

 there is sufficient descent towards the streams, so that drains can be made with 

 but little difficulty. Frequently, the partial or entire saving of a crop would 

 result from a thorough drainage of the surface. Wheat, corn and hay are the 

 principal products of the prairie, but other grains, and fruits, adapted to the 

 climate, may bo grown with more or less success. 



In the vicinity of the water courses, the land is more rolling and hilly, and 

 the subsoil comes nearer the surface, and a portion of the humus has been 

 washed out of the soil, leaving it much less fertile, but better adapted to some 

 kinds of crops, particularly fruits. For ordinary purposes these soils require 

 little or no draining. In their uncultivated state they produce good timber: 

 the common varieties of oak, hickory, elm and ash, sugar and white maple, 

 wild cherry, black walnut, butternut and hackberry. 



Along the Illinois river bluffs, grapevines are very abundant, more so than I 

 noticed elsewhere. I saw but few vineyards in the portions visited, but the 

 abundance and luxuriance of the wild vines would seem to indicate that here 

 is a favored locality for the culture of the grape. Along these bluffs but little 

 draining would be necessary, though in most places where the grape has been 

 successfully cultivated, it has usually been found to pay to underdrain even 

 where the soil appeared, to the unpracticed eye, dry enough. Underdrains are 

 profitable, not only to carry off the surplus moisture, but also to give the at- 

 mosphere a chance to act more readily and thoroughly upon the subsoil. This 

 action is necessary to assist in dissolving and preparing the mineral food for 

 the vine, which sends its roots deep into the surrounding soil for this very 

 nourishment. 



The finest apple orchards in the county are found on these " barrens," and 

 most other kinds of fruit succeed best on this kind of soil. 



