THE SOURCE OF THE NILE. 709 



of water comes in to Egypt, or what quantity of ground it is 

 fumcient to overflow, unlefs the dykes were to be kept clofe 

 till the Nile attained its extreme height, which would be about 

 the 25th of September, long before which it would be over 

 the banks and mounds, if they held in till then, or have 

 fwept Cairo and all the Delta into the Mediterranean, and if 

 it mould not do that, it would retire fo late from the fields 

 as to leave the ground in no condition to be fown that yean 



I do not comprehend what idea other travellers have 

 formed of the beginning of the inundation of the Nile, as 

 they feem to admit that the banks are not overflowed; and 

 this is certainly the cafe ; becaufe the cities and villages are 

 built there as fecurely as on the higheit part of f'gypt, and 

 even when the Nile has rifen to its greatefl height they ftiLl 

 are obliged to water thofe fpots with machines. In another 

 part of the work it is explained how the califhes carry the 

 water upon the lands, approaching always to the banks as 

 the river rifes in proportion, and thefe califhes being deri- 

 ved from the Nile at right angles with the flream, and carry- 

 ing the water by the inclination of the ground, in a di- 

 rection different from the courfe of the river, the water is 

 perfectly flagnated at the foot of the hills, till accumulated 

 as the flream rifes, it moves in a contrary direction back- 

 wards again, and approaches its banks. But when the in- 

 undation is fo great that the back-water comes in contact 

 with the current of the Nile, by known laws it mufl par- 

 take the fame motion with it, and fo all Egypt become one 

 torrent. 



Br 



