Sele 
454 IRRIGATION IN EGYPT. 
whole land,* and, with the exception of a narrow strip of 
coast, where the annual precipitation is said to amount to six 
inches, the fall of rain in the territory of the Pharaohs is not 
two inches in the year. The subsoil of the whole valley is 
pervaded with moisture by infiltration from the Nile, and water 
can everywhere be found at the depth of a few feet. Were 
irrigation suspended, and Egypt abandoned, as in that case it 
must be, to the operations of nature, there is no doubt that 
trees, the roots of which penetrate deeply, would in time 
establish themselves on the deserted soil, fill the valley with 
verdure, and perhaps at last temper the climate, and even call 
down abundant rain from the heavens.+ But the immediate 
effect of discontinuing irrigation would be, first, an immense 
reduction of the evaporation from the valley in the dry season, 
and then a greatly augmented dryness and heat of the atmos- 
phere. Even the almost constant north wind—the strength of 
which would be increased in consequence of these changes— 
would little reduce the temperature of the narrow cleft between 
the burning mountains which hem in the channel of the Nile, 
so that a single year would transform the most fertile of soils to 
the most barren of deserts, and render uninhabitable a ter- 
ritory that irrigation makes capable of sustaining as dense a 
population as has ever existed in any part of the world. 
Whether man found the valley of the Nile a forest, or such a 
waste as I have just described, we do not historically know. 
In either case, he has not simply converted a wilderness into a 
* The so-called spring at Heliopolisis only a thread of water infiltrated from 
the Nile or the canals. 
+ The date and the doum palm, the sont and many other acacias, the caroub, 
the sycamore and other trees grow in Egypt without irrigation, and would 
doubtless spread through the entire valley in a few years. 
+ Wilkinson states that the total population, which, two hundred years ago, 
was estimated at 4,000,000, amounted till lately to only about 1,800,000 souls, 
haying been reduced since the year 1800 from 2,500,000 to less than 2,000,000. 
—Handbook for Travellers in Egypt, p. 10. The population at the end of the 
year 1869 is computed at 5,215,000.—Bollettino della Soc. Geog. Ital., vol. v., 
pt. iii, p. 215. This estimate doubtless includes countries bordering on the 
upp-r Nile not embraced in Wilkinson’s statistics, 
