Irrigation in Africa 85 



against the watered area, which begins at Assuan, some 500 miles 

 from the sea, not following the windings of the Nile. The popu- 

 lation of this country is now given as 5,000,000, but it has been 

 estimated that Egypt once supported 20,000,000 inhabitants ; and 

 a practice of today, which will seem strange to the reader, is 

 that of digging up the rubbish piles on the sites of ancient vil- 

 lages, towns and cities, which represent the waste of the millions 

 who have passed away, and using this as manure to fertilize the 

 fields now under irrigation. The dry climate of this country has 

 preserved these materials from complete decay, and the site of 

 old Cairo is now being dug over to enrich the fields for miles 

 around. 



The mean daily discharge of water which passes from Upper 

 Egypt, at Cairo, into Lower Egypt is estimated at 8,830,000,000 

 cubic feet, but as large as this amount is, it would require 20 

 days to place Wisconsin under an inch of water. 



In the Algerian Sahara, since the sinking of the first artesian 

 well, in 1848, at Biskra, by M. Henri Fournel, the work went for- 

 ward, until in 1875 there had been 615 wells put down, having 

 an average depth of 145 feet, 404 of which are in the province of 

 Constantine, 194 in the province of Algiers, and 15 in that of 

 Oran. A strange thing about these artesian waters is the pres- 

 ence in them of nitrates, and irrigation with them has brought 

 upon the desert sands wonderful oases, 43 in number in the Oued 

 Rir, supporting, in 1885, 520,000 date palms of bearing age, 140,- 

 000 palms from one to seven years old, and about 100,000 other 

 fruit trees. 



On the south side of the equator, in Africa, there has as yet 

 but little been done in the way of irrigation, although in Cape 

 Colony efforts are being made. In 1889 the U. S. Consul at Cape 

 Town, Geo. F. Hollis, states that the most complete storage work 

 now constructed in the colony, and the most important, is that at 

 Van Wyck's Vley. The rainfall in this section is very irregular, 

 the average for 11 years being 10 inches. The reservoir has de- 

 pended upon a catchment area of, say, 240 square miles, but this 

 has been found inadequate, and a furrow is now nearly com- 

 pleted to bring over water from a neighboring river, by which it 



