Prince Louis Napoleon, who, in 1846, published a remarkable work, inserted in the Revue Britannique, under the title of Canal de Nicaragua, adopted the same dimensions as Mr. Garella, in the project which he proposed to execute for establishing the communication between the Atlantic and Pacific Oceans.
We have assumed on considerations hereinafter to be explained, that paddle and screw frigates as well as vessels of 1000 to 1500 tons, ought to be able to traverse the Canal in order to satisfy to the fullest extent the demands of navigation. We have therefore fixed the width of the Canal at the water line at 100 met.; its minimum draught of water at 6 m., 50, below low water in the Mediterranean. The locks, two in number, are to be 100 met. long, 21 met. wide, with a minimum depth of water of 6 m., 50. These works will be established at the two extremities of the Canal, immediately before the dykes forming the channel which on each side unites the Canal with the two Seas. These two locks will form part of a sluiced barrage, and thus convert the whole Canal into one immense dam, receiving the waters of the Red Sea during the highest tides, and storing them up successively in order to raise the level and create a rush of water in each channel when necessary. The highest tides of the Red Sea being from 2 met. to 2 m., 50 above low water in the Mediterranean, a depth of 9 met. of water will be obtained in the canal at certain times, but a mean super elevation of 1 m. may be depended on, which will usually give a minimum depth of 7 m., 50 to 8 met. Under these conditions, screw steamers will be enabled to pass easily along the Canal without the presence of its bed re-acting in an inconvenient manner on the motion of their screws. We have, however, calculated the earth-works for three different depths of water, viz. 6 met.; 6 m., 50; and 7 met. below low water in the Mediterranean. If the Company should require a depth of 8 met., it would be easy to obtain it by means of dredges, without stopping the navigation on the Canal.
The length of each barrage, including the lock, is 100 met.; and in order farther to facilitate the entrance of the rising tide into the Canal, a third barrage has been added at Suez on the site of the existing channel. This last work will be separated from the first by a platform raised above the level of high water, so that the two together will unite the road from Cairo passing by Suez to Mecca. Its length has also been fixed at 100 met.
For reasons of economy the width of the Canal has been reduced to 65 met. wherever the height of the ground reaches 6 met.
To prevent the degradation of the banks of the Canal, the slope has been fixed at two on the base to one in height, and it is proposed to have a causeway 2 met. broad to receive, 1st. A covering of the broken stones found along the Canal, 2nd. Any earth falling from the higher grounds, which would otherwise encumber the bed of the Canal. This is only an imitation of what has proved so successful on the Caledonian Canal.
The width of the towing path has been fixed at 4 met., which is quite sufficient for a maritime canal where steam towing will be so much in use.
Lake Timsah, situated nearly midway between the two Seas, at the entrance of the Wady Tomilat, will form, as we have said, an inland port, to which both the outward and inward navigation will tend. On its shores will be established magazines, stables, workshops for repairs, as well as 1500 metres of quay walls for mooring vessels and embarking merchandize. For, as the illustrious author of the work on the canal of Nicaragua well expresses it, the proposed Canal must not be a mere cutting destined solely to form a passage from one sea to the other for the produce of Europe, but it must make Egypt a prosperous state by enabling her to dispose of her interior produce, and a powerful one by the extent of her commerce.
As for the two entrances, whether from the Red Sea or the Mediterranean, all that is necessary is, that ships shall be able to approach at all seasons, and find certain and effectual shelter in bad weather. Now the roadstead of Suez is sheltered from every wind except the south-east. It will therefore be sufficient to prolong the eastern jetty to a certain distance beyond the western to render the shelter complete.
All the vessels which now take their stations in the roadstead ride out the bad weather very well, and the magazine corvette belonging to the English Company which has been anchored there for the last two years and a half has suffered no damage.