283 
from the Nile to the Red Sea. 
which intersects the valley near Thaubastum , the water in the 
Bitter Lakes could be kept at any level from 2 or 3 feet above 
low water in the gulf, to 4 feet under it. If, then, the fresh wa- 
ter cut from the Nile was made to terminate at the north end of 
the Bitter Lakes (the Serapeum) instead of Arsinoe, a very ob- 
vious advantage would be gained. Assuming that the water of 
the Nile, when it reached Arsinoe, at the extreme height of the 
inundation, was 2 feet above the low-tide level, it is plain that 
the communication with the sea could be kept open only during 
the time the Nile rose and fell through these 2 feet ; that is, pro- 
bably six weeks * But as the level of the lakes, by means of 
the regulating sluice, would be fixed at any point, from 2 or 3 
feet above, to 4 feet under, the low tide ; that is, from the ex- 
treme height of the Nile to a point 6 or 7 feet below it, it is plain, 
that, if the fresh- water canal terminated in the lakes, the communi- 
cation with the sea could be kept open four months instead of six 
weeks. The marine current could occasion no serious difficulty. 
It would he merely a salt river like the Hellespont, in which 
ships could sail as easily as in the fresh-water current of the 
Nile. This hypothesis is submitted without any intention of 
denying that the fresh water was carried at one period to Ar- 
sinoe, as the French engineers suppose. That the plan here 
sketched was adopted at another period, is not improbable. That 
it would suggest itself seems scarcely disputable ; and it is cer- 
tain, that there is nothing in it either inconsistent with existing 
appearances, or beyond the reach of the mechanical resources 
which the ancients possessed. 
The general features of this inland navigation will now be to- 
lerably understood. It consisted, according to the French en- 
gineers, of a canal extending upon one level, from Bubastis to 
Arsinoe, and carrying the waters of the Nile to the Red Sea. Its 
breadth between the Bitter Lakes and the Gulf, appears, from the 
remains, to have been about 35 or 40 metres (115 to 130 Eng- 
lish feet) at the water line. At the other end, where it received 
a greater depth of water, it was probably a half wider ; and, to- 
wards the middle, from Ras-el-Wadi to the Serapeum, where 
* The extreme rise and fall of the Nile at Bubastis is 18 feet. It is not quite 
equable ; but where precision is not required, the change may be assumed at 3 feet 
per month. 
