CONTENTS. 



CHAPTER I. 

 SOURCES OF WATER. 



Introduction. Rainfall in the United States. Run-off. Evaporation. Ab- 

 sorption. Recovery of natural supplies. Sources of farm supplies. 



CHAPTER II. * 

 SURFACE WATERS. 

 Sources. Lakes. Ponds. Artificial Ponds, etc. Streams. 



CHAPTER III. 

 SPRINGS. 



What a spring is. Source of water. Kinds of springs. Gravity springs. Ar- 

 tesian springs. Seepage springs. Tubular springs. Fissure springs. Im- 

 portance of springs. Safety of springs. Tests for pollution. Protection of 

 springs. Protection of sink holes. Piping of springs. 



CHAPTER IV. 

 GROUND WATERS AND THEIR OCCURRENCE. 



Derivation of ground waters. Absorptive capacity of soils and rocks. Porosity of 

 soils and rocks. Total water in the ground. Methods of absorption. Waters 

 from lakes and streams. Underground waters and mountains. Underground 

 rivers. Underground lakes. Temperature of underground waters. 



CHAPTER V. 

 WATER-BEARING FORMATIONS. 



Classes of rocks. Unconsolidated sedimentary deposits. Consolidated sedimentary 

 rocks. Igneous rocks. Metamorphic and crystalline rocks. Fossils. For- 

 mations. Structures of rocks. 



CHAPTER VI. 

 SOURCES AND SAFETY OF UNDERGROUND SUPPLIES. 



Waters of sands and gravels. Waters of clays. Waters of tills. Waters of sand- 

 stones, conglomerates and quartzites. Waters of slates. Waters of lime- 

 stones. Waters of granites, gneisses and schists. Safety of rock waters. 



