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Improved System of Irrigation. 



the purity of its composition (freedom from mineral properties), 

 in which case the water will be as good at last as at first ; and 

 2ndly, for what it holds in solution, not for what it carries in an 

 insoluble state, for that should be deposited. Now, as long as 

 this water is kept in motion it carries its solved substances with 

 it, and the plant (grass) that takes up the material solved takes 

 up the water also ; so that as the water loses its quality it also 

 loses its volume, partly by evaporation and partly by absorption 

 by the grasses, consequently the water that remains must be just 

 of the same quality as at first. 



I have not tried any analytic experiment to prove the truth of 

 what I have here stated, nor do I think it necessary to do so, as it 

 is of no consequence whether it be true or not to a few quarts of 

 diminution more or less ; but this we hioiu, water does evaporate, 

 and that vegetables do decompose water for their own nutrition ; 

 we know that evaporation carries off little or none of the solved 

 matter. Upon this I found an argument, and take it as proved, 

 that as the water diminishes in volume as well as in quality, and 

 that if those diminutions went on in exact ratio, then the water 

 would remain, under all circumstances, precisely of the same 

 quality ; and that for all practical purposes which we have now 

 under consideration, it does so remain. The most satisfactory 

 proof of the truth of this argument is found in the answer given 

 by the meadows themselves, viz. that it is true : experience has 

 assured that the above reasoning is correct ; the water is good to 

 the last. 



It is very difficult to prove it by experiments in nature in every 

 case. The water will act best upon the best land : therefore to 

 expect water to exhibit as much good effect on the lower end of 

 a meadow, where the soil is inferior in quality, as it shows on the 

 higher end, where the soil is superior in quality, is to expect what 

 reason ought not to ask, and that to which nature will never 

 respond. 



But these small gutters are sufficient when the little stops 

 are taken out of the perpendicular gutters, and the level gutters 

 are stopped so as to confine the water to the perpendiculars, to carry 

 down as much water as ought to be carried down. The level 

 gutter of a lower section (if it is determined that a lateral section 

 shall be watered), instead of being fed by a large stream at the 

 end, is supplied every ten or fifteen paces by one of those little 

 gutters, thus giving an uniform supply throughout the length of 

 the level gutter. A larger supply than this will afford is an evil, 

 not a good ; you do not want to wash the surface of your land, 

 you want to irrigate it. But this fashion of sending down the 

 water is not what I advise ; I only say it can be done if 

 required. I advise that the sections ])egin at the head : a surplus 



