IRRIGATION MEANS AND ENDS. 75 . 



Austrian Alps, which Providence seems to have 

 specially adapted to be improved by irrigation. The 

 torrents of melted snow which in Spring leap and 

 foam adown the southern face of the Alps, bringing 

 with them the finer particles of soil, are suddenly 

 arrested and form lakes (Garda, Maggiore, Como, 

 etc.) just as they emerge upon the plain. These 

 lakes, slowly rising, often overflow their banks, with 

 those of the small rivers that bear their waters west- 

 ward to the Po ; and this overflow was a natural 

 source of abiding fertility. To dam these outlets, 

 and thus control their currents, was a very simple 

 and obvious device of long ago, and was probably 

 begun by a very few individuals (if by more than 

 one), whose success incited emulation, until the pres- 

 ent extensive and costly system of irrigating dams 

 and canals was gradually developed. "When I trav- 

 ersed Lombardy in July, 1851, the beds of streams 

 naturally as large as the Pemigewasset, Battenkill, 

 Canada Creek, -or Humboldt, were utterly dry ; the 

 water which would naturally have flowed therein 

 being wholly transferred to an irrigating canal (or to 

 canals) often two or three miles distant. The reser- 

 voirs thus created were filled in Spring, when the 

 streams were fullest and their water richest, and 

 gradually drawn upon throughout the later growing 

 season to cover the carefully leveled and graded fields 

 on either side to the depth of an inch or two at a 

 time. If any failed to be soon absorbed by the soil, 

 it was drawn off as here superfluous, and added to 



