468 



ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1915. 



are the succeeding problems of settlement and utilization of the 

 works. These later problems, involving the human element, less 

 susceptible of mathematical statement, require correspondingly more 

 judgment, as well as patience and tact. 



Fig. 1. — Principal reclamation projects. 



The physical management and operation of an extensive reservoir 

 and canal system, in which the quantity of flow is regulated at all 

 points and all times according to design, is in itself an intricate 

 problem, akin to railroad management, but in addition this already 

 involves dealing with 25,000 individuals who are dependent on the 

 Government systems for the most vital requisite in their daily occu- 

 pation of irrigation farming and who are depended upon in turn 



