THE GLEANERS 95 



the high capitalization that follows irrigation, 

 it is becoming more and more profitable to add 

 drainage as a necessary adjunct to all ir- 

 rigation systems. The results are two-fold. 

 In the first place the surplus water can be 

 carried off and used to irrigate lands lying 

 at a lower level, and, in addition, it has been 

 found that drainage prevents the accumula- 

 tion of alkali at the surface of the ground. 

 This latter discovery is of immense economic 

 importance because whole countries have been 

 rendered sterile by the accumulation of alkali 

 due to the circulation of the water of irrigation. 



These facts regarding drainage, its scope 

 and economic importance, are specially in- 

 teresting because we are still in the infancy 

 of the movement. 



Yet, remember that the little nation of Hol- 

 land, whose acres support 450 souls to the 

 square mile, began diking and draining its 

 empire nearly 400 years ago, and that to-day 

 nearly two-thirds of Holland lies below the 

 sea level. When we think of Holland there 

 comes before us a picture of windmills. 

 Windmills were pumping water in Holland 

 before Christopher Columbus sailed out on his 

 voyage of discovery. The development of 



