20 IRRIGATION. 



that these examples are taken from streams, the waters of 

 which were carefully examined, with a view to their value 

 and use for domestic supply of various neighboring cities; 

 and if these waters, selected for their purity, contain so 

 much foreign matter, how much must be contained in 

 those turbid streams, the waters of which are not only 

 highly charged with soluble matter, but carry in suspen- 

 sion solid matter of which vast banks are sometimes de- 

 posited in the course of a few weeks or months. 



The value of all the water which now passes away useless- 

 ly, but which might be arrested and made to deposit on the 

 soil, or convey to the roots of crops, its burden of fertiliz- 

 ing matter, if it were made useful in irrigation, is more 

 than can be readily calculated. An estimate made by 

 Herve Mangon in his work entitled Experiences sur 

 Vemploi des eaux dans les irrigations, of the yearly value 

 of the solid matter conveyed into the ocean by the river 

 Seine, may be cited. He says: "each 200,000 cubic 

 meters of water employed in irrigation, will produce a 

 quantity of alimentary substances equal to one average 

 butcher's beef. Then the waters of the Seine that are 

 lost from the services of irrigation carry into the sea the 

 equivalent of one fat ox every two minutes, or 720 every 

 twenty four hours, or 262,800 in the year." As compar- 

 ed with American rivers the Seine is a small stream; what 

 then might be the value of the Missouri, or the Mississip- 

 pi, with its affluents, or any one or all of our other rivers 

 and streams, great and small, that now pay no tribute to 

 us in this direction in any way whatever. 



