He determined, therefore, to establish a large dock-yard at Cherbourg, not merely for repairing, but also for the construction of the largest clam of ships of war; to dig a basin that should contain 50 or 60 sail of the line ; to construct dry-docks and slips for building and repairing, and to make it a naval port of the first rank. In 1818, this basin was completed at an expemce, as Bonaparte is said to have asserted when on board the Northumberland, and which has since been confirmed, of L.8,000,000 Stet ling. A wet-dock of the same magnitude, comma. mating with it, was then commenced, and is now in description that we have been able to find in print of this great work, which took ten yams in carrying into execution, is contained in a short letter from M. Pierre-Aima Lair, Secretary to the Society of Agriculture and Commerce 'of Caen, who was present at the ceremony of opening and cone. crating the great basin, in presence of the-Empress Maria Louisa, the 27th August 1813. He describes this basin to be excavated out of a rock of granite schist, or psis, the density and . hardness of which increased as the workmen descended from the sur face. He compares it to an immense trough dug out of a single stone, and capable of containing many millions of cubic feet of water. We now know, how ever, that Mr Lair is mistaken ; that jt is not one mass of rock, but rock and gravel mixed ; that the whole of the sides are cased with a well con structed wall of red granite; and that a noble quay, built of the same material, and extending between the two forts of Galet and Hemet, separates the ba sin and wet-dock from the sea.
The dimensions of the new basin he states to be about 900 • feet in length by 720 in width, and the average depth 55 feet from the edge of the quay ; and as this edge is five feet above the high water mark of the equinoctial spring-tides, the depth of water in the basin is then 50 feet, and the mass of water, after making allowance for a slope of the solid sides inward in an angle of from the height of about 25 feet, amounts to about 30 millions of cubic feet; and that it is calculated to contain about 80 sail of the line. We have reason to think that it is considerably larger; about 1000 feet by 770 feet, and eonsequently contains a surface of about 1$ acres, which, at three per will contain 54 sail of the line, and the adjoining wet•dock, when finished, an equal number. The latter is at this time about two thirds completed, and from 800 to 400 men are em ployed in blaming the rock and building granite walls. The dike or breakwater seems to be abandoned; the works having long been stopped, and the stone ves sels going rapidly to decay. The French officers my, indeed, that it has occasioned the roadstead to become shallower, by the deposition of sand that has taken place.
The entrance canal leading from the outer har bour into the basin is at right angles to the latter, and its direction ENE. Its dimensions are as under: Feet. Is.
Width between the two moles in the direc tion of their axis, 196 8 Width at its opening into the basin, $08 8 Length from the axis of the moles or piers to the line of wall forming the side of the basin, 274 0 The basin, having no gates, is said to be excavat ed to the depth of nine feet below the bottom of the canal, the former having, as before mentioned, 60 feet water, and the latter only 41 at high spring-tides, which, as they ebb 20 feet, would leave 21 feet in the passage or canal at low water. This mequali
ty, we presume, is intended to keep the in the basin at low water, when the depth in the canal is not sufficient for that purpose ; but after so much expence incurred in digging the basin, one would suppose a little more might have been ex pended in digging the canal to the same depth, so as to let ships pass into and out of the basin in all states of the tide ; an advantage of the utmost ink speedily securing their ships in the hen in danger of an attack from the enemy in the roadstead, or of speedily putting to sea and escaping the vigilance of a blockading squadron. No reason is assigned for leaving the basin without gates; but we suspect that Mr Lair is again mis taken, and that the passage has depth of water suf ficient for ships of the largest class to run into the basin at all times of the tide. But even here they do not lie in safety ; for the wide entrance facing the NE. is covered only in that direction by the Isle Pelee, so that the water in the basin partakes of the swell in the road, which is sometimes so great as to make it necessary to apply 10 or 12 cables to hold ships steady in the Another serious inconvenience is likely to arise from this particular construction of the basin. Whatever silt or mud is carried in by the tides must be depo sited there, and cannot possibly escape. The quan tity is probably not very great in the water of the Channel opposite to Cherbourg, but, higher up, to wards Ostend, it is very considerable. When we took possession of that port, it was found that, in the course of the Revolutionary war, the harbour, by neglect, was filled up with six or seven feet of mud.
Several pieces of cannon are intended to be mount ed on the two piers, to protect the entrance into the basin. On one of them is likewise placed a light house, and on the other telegraph. Four slips of granite, for building large ships, were at this time, constructed on the southern side of the basin; and on each of them was a ship of the line in progress, L'Inflexible of 118 guns, Le Centaurs of 80, Le Jupiter and Le Gateaux of 74 guns each. Two other ships of the line were on the stocks without the dockyard, nearly ready for launching, Le Zelandais of 80, the first line of battle ship laid doivn at Cherbourg, and the Duguay-Trouin of 74 pins ; and in the roadstead were Le Polonais and Le Courageux. In the centre of the same side of the basin, with two slips on each side of it, a noble dry-dock was cut out (or built rather) of solid gra nite, in which ships of the largest class might be built or repaired. Its dimensions were, Thus the ships built on the four slips may be launch ed into the basin, and at once docked out of it.