380 
WATER WITHDRAWN FOR IRRIGATION. 
are often wholly diverted from tlieir natural channels to sup¬ 
ply the canals, and their entire mass of water completely 
absorbed, so that it does not reach the river which it naturally 
feeds, except in such proportion as it is conveyed to it by infil¬ 
tration. Irrigation, therefore, diminishes great rivers in warm 
countries by cutting off their sources of supply as well as by 
direct abstraction of water from their channels. We have just 
seen that the system of irrigation in Lombardy deprives the 
Po of a quantity of water equal to the total delivery of the 
Seine at ordinary flood, or, in other words, of the equivalent 
of a tributary navigable for hundreds of miles by vessels of 
considerable burden. The new canals commenced and pro¬ 
jected will greatly increase the loss. The water required for 
irrigation in Egypt is less than would be supposed from the 
exceeding rapidity of evaporation in that arid climate ; for the 
soil is thoroughly saturated during the inundation, and infil¬ 
tration from the Nile continues to supply a considerable 
amount of humidity in the dryest season. Lin ant Bey com¬ 
puted that twenty-nine cubic metres per day sufficed to irri¬ 
gate a hectare in the Delta.* This is equivalent to a fall of 
rain of two millimetres and nine tenths per day, or, if we sup¬ 
pose water to be applied for one hundred and fifty days during 
the dry seasons, to a total precipitation of 435 millimetres, 
about seventeen inches and one third. Taking the area of 
actually cultivated soil in Egypt at the low estimate of 
3,600,000 acres, and the average amount of water daily applied 
lead not unfrequently to ruinous injustice toward individual landholders. 
These circumstances discourage the division of the soil into small proper¬ 
ties, and there is a constant tendency to the accumulation of large estates 
of irrigated land in the hands of great capitalists, and consequently to the 
dispossession of the small cultivators, who pass from the condition of 
owners of the land to that of hireling tillers. The farmers are no longer 
yeomen, but peasants. Having no interest in the soil which composes 
their country, they are virtually expatriated, and the middle class, which 
ought to constitute the real physical and moral strength of the land, ceases 
to exist as a rural estate, and is found only among the professional, the 
mercantile, and the industrial population of the cities. 
* Boussingault, Economic Rurale y ii, pp. 248 , 249 . 
