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size of the bed, to arrive at a conclusion, it becomes necessary to assign definite dimensions to the navigable channel between the two seas.
We have to consider the number of ships likely to be passing and repassing through the channel, the size of such ships, and steam-vessels destined for long voyages, and lastly, the degree of current necessary to keep the bed and outlet of the canal clear. To meet these conditions I propose the canal should be twenty-one feet deep and ninety-six feet wide at bottom, with sides sloping two to one, and consequently having a width at top of one hundred and eighty feet, the length of each slope being forty-seven feet nearly.
It has been stated that the fall between the two seas amounts to 4*731 inches per English mile, or 9*462 inches in two miles. We therefore have, by the usual formula,
y (18C-|-96)=2898 square feet sectional area of canal.
(2 x 4<7)-{-96=190 feet length of line of bed on the cross section.
Wo 8 = 15‘25 feet, or 183 inches, the hydraulic depth of the stream.
v/183* x 9*462=37*83 inches per second for the velocity of the current, being nearly at the rate of 2*15 mile per hour, just the amount of current likely to be effective for scourage, and yet not difficult to navigate against. The highly saline nature of the water of the Red Sea, and its consequent great specific gravity may possibly increase the velocity of the current to two and a quarter miles per hour; but at the end of eight miles this current would commence to be impeded by the pressure of the Mediterranean Sea; and it might therefore become a question how far a straight or curved gradient for the canal would best answer all the ends in view. Some engineers have proposed to carry the canal for the greater part of the distance nearly level, and to throw the fall chiefly on the