298 AGRICULTURE 



back the other. It distributes the moist earth evenly and pre- 

 pares a smooth hard surface from which rain runs off. 



Care of Roads. No matter how well built a road is, it becomes 

 bad if it is not given proper care. Drains should be kept open; 

 depressions should be filled with the material of the roadbed before 

 they become mudholes. It is easier and less costly to keep a road 

 good than to repair a bad one. 



EXERCISE 



Compare the best road or street with the worst one that you know. 

 What are the chief points of difference ? How could the bad one be 

 improved ? 



THE HELP OF SCIENCE 



Work of Farmers. Year after year, century after century, 

 farmers learned facts by observation and developed methods by 

 experiments. These facts and methods were handed down from 

 father to son and grandson. They were accepted and practiced 

 with little knowledge of the underlying principles. 



Studies of Scientists. Instead of investigating and explaining 

 these principles, students devoted themselves chiefly to pure 

 science. Chemists, for instance, gave farmers little more aid than 

 did astronomers. The last sixty years, however, has witnessed a 

 great change. Scientists have turned their attention more and more 

 to practical subjects. Chemists have analyzed soils, learned what 

 elements plants need for food and in what forms these must be 

 supplied; they have found out which of these available elements 

 are sometimes lacking, and how they may be supplied by chemicals. 

 The result of these investigations is the production and use of mil- 

 lions of dollars' worth of fertilizers and a vast increase in the pro- 

 ductive power of land. 



