Water 49 



reason, until very recently, men fishing for sport frequently had 

 to seek out new streams. 



Today, science is changing this. By scientific methods of 

 catching, curing, canning and shipping fish, the fish supply may 

 be distributed throughout the world to points of need. More- 

 over, the fish supply in small and in large bodies of water is being 

 safeguarded in various ways. Laws now limit the size of the 

 catch and the times during which fish may be caught. Other 

 laws, which prohibit the emptying of impurities into the waters, 

 also help to protect fish. In addition, fish hatcheries have been 

 established under state and under national control and are doing 

 wonders in restoring the supply of fish. These institutions hatch 

 fish by the millions and, 'by means of scientifically designed tank 

 cars, distribute them over the entire country. 



The uses of water for pleasure, for health and for recreation 

 should not be overlooked. Boating, bathing and swimming all 

 make for the health and strength of a people. Especially at or 

 near large centers of population, provision for these sports means 

 very much for community welfare. 



Water will flow and under proper conditions will exert pres- 

 sure. Upon these properties depends its immense value in indus- 

 try and commerce. As it flows in streams, it affords opportuni- 

 ties for transporting material from place to place, making trade 

 between these places possible. The ocean, also, has been for 

 centuries a highway for trade. 



The unevenness of the surface of a country is due largely 

 to the action of running water. Water hollows out valleys and 

 causes the irregular outline of highland and mountain ranges. 

 Evidences of this wearing action may be observed in the garden 

 or along the roadsides during and after hard rains. 



Water is called the great solvent because of its power of dis- 

 solving so many materials with which it comes in contact gase- 

 ous, liquid or solid. Flowing streams are continually bearing 

 oceanward materials in solution. Consequently the oceans are 

 great storehouses of matter deposited by streams and rivers. 



Some Simple Experiments to Show the Properties of 

 Water. From the height of a few feet, pour water from a 



