108 THE ANCIENT EGYPTIANS. CHAP. XI. 



impediment to the arbitrary overflow of the inun- 

 dation : the general direction of a dyke, therefore, 

 varying according to circumstances, may be re- 

 presented as in the accompanying plate.* 



It is on a plain of about five miles in breadth. 



Some dykes are even more circuitous and indi- 

 rect than this ; but, in all cases, the principal care is 

 to place them so as to oppose the greatest force to 

 the largest body or pressure of water, and to offer 

 the readiest means of communication from one 

 village to another. 



I have already observed that the perpendicular 

 deviation of the bed of the river, and the propor- 

 tionate elevation of the water of the iniuidation, 

 tend to increase the extent of the arable land of 

 Egypt ; and that there is now a larger tract of cul- 

 tivable soil E. and W. from the river, than at any 

 previous period. This I shall endeavour to illus- 

 trate by a similar section t, in which it will be seen 

 that if the Nile, rising from its ancient bed A B, 

 inundated the country in the direction and at the 

 elevation EF, it would, when raised to CD, its mo- 

 dern bed (the land being also raised in proportion 

 to G), extend its inundation on the line GH to a 

 far greater distance over the hdger, or slope of the 

 desert, and give an additional tract of cultivable 

 land from F to H. 



That this has actually taken place, I have satis- 

 factorily ascertaine 1 by excavations, and by ob- 

 serving the quantity of alluvial deposit accumulated 

 round the base of ancient monuments, and by a 



* Plate 18. No. -2. t No. 3. 



