l^o On a Junction of the Red Sua 



mg to ever)' account, the nature of the ground will oppofe 

 the full execution of theic two objects, and fcems to {how 

 that they might thwart each other. The only method 

 then is to weigh them both together, taking matters even in 

 the worft light ; and to determine the queftion I propofe 

 the following preliminary confiderations : 



i . The lead elevation which the canal ought to have 

 from one end to another, fliould be equal to that of the 

 grcaieft tides or fwellings of which the Red Sea is fufceptiblc. 

 The level of the canal would be thus fixed, and all the dif- 

 ferences from the higheft to the low eft rifing of the fea 

 would be counteracted by one or two locks, as it might be 

 pofiible to counteract at the other end all the overflowings 

 of the Nile, which probably rife higher, and which in that 

 cafe would require flood-gates. 



2. There are two other methods which might be adopted 

 in the like cafe, but which would be far lefs advantageous. 

 One of thefe, which would fave the necefiity of locks both 

 towards the fea and towards the Nile, is, not to allow boats 

 or other veflels to come from or enter the fea but twice a day 

 at the times of the tides, and not to come from or enter the 

 Nile but when it is at its greateft heights. But this would 

 lay too great a reftraint on commerce, particularly at Cairo, 

 where the tranfportation of goods would not be pofiible but 

 during two or three months : but ftill the level would be- 

 come doubtful and variable, like all tides and inundations ; 

 and there would neceflarily be alternate currents, which 

 would render the water brackifh and unhealthful, not only 

 in the canal, but alfo in the Lower Nile. 



3. The other method, in order to exclude locks altogether, 

 or at lead in part, would be7 to deprefs mere the bed and 

 level of the canal, taking care to guard it at each end by the 

 flood-gates, which would permit veflels to enter the fea or 

 the river at the times of their greateft elevation. But,l:hough 

 this method might render the courfe of the navigation freer 

 smd lefs interrupted, it would not prevent the mixture of the 



frefh 



