Prevention and Eradication 75 



occupy the banks of canals and main drains which are entirely 

 open to pollution. At the present day, as in the time of Herodotus, 

 " The Egyptians perform publicly those natural functions which it 

 is the custom for members of other races to carry out in private." 

 In the new areas now being reclaimed, it should be possible to 

 provide more adequate protection for the main watercourses. 



The replacement of the small agricultural drains by piping or 

 by " mole " drains, together with the proper utilization of canal 

 clearances and the periodical drying of the small canals during 

 the summer " rotations," should prove successful in controlling 

 bilharzia, even although the molluscan intermediaries were not 

 entirely destroyed. The molluscs are slow in growth and propaga- 

 tion as compared with other animal carriers of human diseases. 

 Ke-stocking with half-grown or adult forms might be prevented if it 

 proved practicable to screen the iron pipe regulating the flow of a 

 tertiary canal at its head. 



Concerning Reclamation. 



At the beginning of the nineteenth century, owing to neglect, the 

 cultivated area of the Delta had shrunk to that portion lying 

 between Cairo and an irregular line (shown on fig. 25) passing 

 through Delingat, Damanhur, Itai el Barua, Shubrakhit, Desuq, 

 Qallin, Simella, Mansura, Faqus, Burdeiu, and Bilbeis. The intro- 

 duction of perennial irrigation brought about a rapid increase in 

 the population of Egypt, which was met by an extension of the 

 area brought under irrigation. This increase still continues and is 

 greatest where irrigation projects are most active. Daring the ten 

 years ending 1907 the population, according to Willcocks, had in- 

 creased sixteen per cent, while the cultivated area increased only 

 thirteen per cent. It is clear, therefore, that new land must be 

 brought continually under cultivation to meet the increasing needs. 

 The total acreage of Lower Egypt is 5,190,000 acres. Of this, 

 3,100,000 acres are now cultivated land, 1,190,000 acres are waste 

 land ("Berea"), or ordinarily too salted to produce crops without 

 reclamation ; 600,000 acres are covered by lakes. The whole of the 

 Berea or waste land was cultivated in the Ptolemaic and Roman 

 era. According to local tradition some of these waste tracts now 

 bordering the lakes were once covered with vineyards or divided 

 into enormous basins planted with wheat. The numberless mounds 

 strewn with bricks and pottery which nowadays arise from these 

 extensive barren plains are evidence that they once supported 

 a dense population. 



