248 IRPJGATION OF LAND. 



spring freshet has subsided and has become clear, is withdrawn by 

 gates phiced in the dams for this purpose, and should be done when 

 least agitated by wind. This method has been practiced in several 

 localities in this country with good success, and in Holland this 

 method is applied where it is said the largest crops and lichest 

 grasses in Europe are obtained. In most cases the surface water 

 may be taken from the ponds in ditches, and carried a great distance 

 on both sides of the streams, and extensive winter irrigation may be 

 eifected and fields reached which could not be irrigated in summer 

 without flowing the lands above the dams, while the soil beneath 

 these winter ponds may receive a portion of the soluble matter con- 

 tained in the water above. Inundation is probably the most perfect 

 method of obtaining the solid or suspended matter, most of which is 

 highly fertile. 



By an analysis of the waters of seventeen rivers, mostly in the 

 northern section of this country, recently published, the average 

 amount of solid matter is over six grains to the gallon, and Dr. 

 Dana estimated the quantity of salts in solution, andof geineor humus 

 (vegetable matters) which were borne seaward past Lowell in the 

 Merrimac river in 1838, as reaching the enormous amount of 840,- 

 OGO tons, enough to give a good dressing to 100,000 acres of land. 

 To arrest and turn this vast amount of fertility, or a portion of it, 

 from its downward course to tlie ocean where it is forever lost, and 

 apply it to the subsistence of man, is one of the grand objects aiid 

 results of these various methods of irrigation. It has been said that 

 water greatly tends to the protection of nearly all farm crops from 

 the effects of frosts, both early and late, wherever it can be resorted 

 to by night application, whenever a frost is indicated, as is done on 

 cranberry meadows. It has been stated that it tends to hasten and 

 promote the growth of the corn crop when applied upon the appear- 

 ance of the silk and tassel, and it will continue to grow rapidly , 

 through the remainder of the season by the aid of irrigation, and it 

 is known that, up to that period the growth of this crop re- 

 quires but a small amount of moisture, after which, a larger quan- 

 tity is requisite for a while. 



It is said by some flxrmer.^ that the grass and hay of a watered 

 field is less palatable to stock, and like that grown in sliady places, 

 is less nutritive tuan that grown without the aid of irrigation. 



