DRAINAGE INVESTIGATIONS. 39 



ers at points scattered throughout the whole huniicl section of the 

 country. Here, as in the newer sections of the West, the present 

 demand is for practical directions for performing the agricultural 

 operations connected with irrigation. 



In both the humid and arid sections, as irrigation becomes more 

 generally practiced, there will be more demand for the study of the 

 scientific questions connected with securing the largest use of the 

 available water supply and the best development of the crops grown. 

 Such work is now being carried on in the sections where irrigation 

 has been practiced for a long time and the available water supply 

 has been put to use, making extension of the irrigated area dependent 

 upon stopping waste and more economical use. This work includes 

 the measurement of losses of water from canals in convevintr it to 

 the place of use and the means of checking them, including the use 

 of canal linings of various kinds; the cleaning of canals; the use of 

 flumes and pipes for distributing water; adaptation of methods of 

 applying water to the character of the water supply and of the soil 

 and subsoil in order to attain and keep up the best moisture condi- 

 tions in the soil; the effect upon the crop of applying water in dif- 

 ferent volumes and at different stages of the crops' development; and 

 the effect of laws and regulations upon the use of water. 



The rice districts of the South have irrigation problems peculiar 

 to themselves, which are being studied. These include pumping, con- 

 struction of field levees, depths at which water should be maintained 

 on fields, systems of controlling the distribution of water. 



Investigations of pumping are carried on throughout the United 

 States, and an expert in that line devotes his time to giving advice 

 on the installation and operation of pumping plants and the prepara- 

 tion of bulletins on the subject. The construction of reservoirs for 

 the impounding of storm and flood waters is also being studied. 



The authority for the irrigation investigations carried on by this 

 Office is broad in its terms, and the purpose always in mind is to 

 render the greatest service possible with the available funds. At 

 present the greatest opportunity is in the section being brought under 

 irrigation. As time passes this work will become less important, and 

 the more scientific work will be expanded. 



DRAINAGE INVESTIGATIONS. 



The drainage of agricultural lands involves the consideration of 

 such a number and variety of factors that to design drainage systems 

 properly requires a knowledge of land and soil conditions obtained 

 only by careful oliservation and no little experience. Every farmer 

 who has desired to improve lands too wet for easy cultivation, as well 

 as every engineer who is called upon to plan the reclamation of 

 swamp lands or those periodically inundated by overflow from 



