One could hardly expect much permanency from a wooden covering sunk into the sea, and it is not surprising that, one by one, they burst, few lasting more than a year. The outbreak of the Revolution put an end, for some time, to the operations at Cherbourg.
When the construction of the Cherbourg breakwater was resumed, the wooden cone system was abandoned, and the stone was simply sunk from vessels of peculiar construction. The breakwater was completed under Napoleon III., at a cost exceeding two and a half million pounds sterling. The actual breakwater itself was finished in 1853,[61] but since [pg 190]that time most important fortifications have been constructed on the upper works. This is the greatest breakwater in the world, its length being nearly two and a half miles; it is 300 feet wide at the base and 31 at the top. The water-space shut in and protected is about 2,000 acres, much of this great area being, however, too shallow for very large vessels.
Taken in connection with the fortifications, this breakwater has a value greater than any other in the world. At the apex of the angle formed by the junction of the two branches of the breakwater there is a grand fort, and it bristles generally with batteries and forts, as indeed does Cherbourg generally. Dr. W. H. Russell wrote of it, in our leading journal in 1860 that, “Wherever you look you fancy that on the spot you occupy are specially pointed dozens of the dull black eyes from their rigid lids of stone.” With its twenty-four regular forts and redoubts, not including those on the mole, floating harbours, building slips, navy-yards, arsenals, and barracks, Cherbourg is a most formidable place.
CHERBOURG, FROM THE SEA.
In England Rennie’s great Plymouth breakwater is the most remarkable specimen, among many others. Its dimensions are not as great as that of Cherbourg, but it was, nevertheless, a vast undertaking. It consists of an immense number of blocks of stone thrown into the Sound, and forms a barrier nearly a mile in length above the surface of the water. This grand work was commenced in 1812, and by the end of the second year about 800 yards of the breakwater began to appear at low water, and the swell was so much broken that ships of all sizes began to take shelter behind it; while the fishermen within its shelter could not judge accurately of the weather outside the Sound, so great was the change. Several limestone quarries near the Catwater were purchased of the Duke of Bedford for £10,000, and some fifteen vessels were constantly employed in removing the blocks, which ranged in weight from one to ten tons. These vessels were of ingenious construction; they had two railways laid along them parallel to each other, with openings in the stern to admit the cars or trucks laden with stones. These were wheeled from the quarry to the quay, and so on to the vessels, till the lines of rails were filled with trucks. The vessels then proceeded to the works, each bearing its load of stone-laden trucks. On reaching the breakwater each truck was wheeled to the opening, and the stones tipped into the sea. During the first five years the amount of stone deposited gradually rose from 16,000 to 300,000 tons per annum. The large masses were first lowered, and then smaller stones, quarry rubbish, &c., to fill up the interstices. The structure was completed in 1841, with the use of 3,670,444 tons of stone[62] and at a cost of something like a million and a half of money. A distinguished French engineer, M. Dupin, who visited the works during their progress, describes in glowing terms the admirable arrangements, the order and regularity visible in all the proceedings. “Those enormous masses of stone,” he remarks, “which the quarrymen strike with heavy strokes of their hammers; and those aerial roads of flying bridges, which serve for the removal of the superstratum of earth; those lines of cranes, all at work at the same moment; the trucks, all in motion; the arrival, the loading, and the departure of the vessels, all this forms one of the most imposing [pg 191]sights that can strike a friend to the great works of art. At fixed hours the sound of a bell is heard, in order to announce the blasting of the quarry. The operations instantly cease on all sides; all becomes silence and solitude. This universal silence renders still more imposing the noise of the explosion, the splitting of the rocks, their ponderous fall, and the prolonged sound of the echoes.”
“The waves,” said Rennie, “were the best workmen” in the construction of a breakwater of rough stones, and on the whole his belief was confirmed, for the storms by which his great work was assailed rather helped than hindered it, by showing the most desirable slope on the sea-side, while comparatively little damage was done. The slope of the stone barrier was, however, by their force changed very greatly. An inclination of three to one was altered to about five to one, and Rennie had recommended that the authorities should take a lesson from nature and finish the breakwater according to her teachings. “It would appear,” says Mr. Smiles,[63] “that Mr. Whidbey, the resident engineer, contrived to finish most of the exterior face at a slope of only three to one, as before; and that it stood without any material interruption until several years after Mr. Rennie’s death. By that time nearly the whole of the intended rubble, amounting to 2,381,321 tons, had been deposited, and the main arm, with 200 yards of the west arm, making 1,241 yards in length, had been raised to the required level. The work had arrived at that stage when it had to experience the full force of another terrific storm, which took place on the 23rd of November, 1824. It blew at first from the south-south-east and then veered round to the south-west, and the effect of this concurrence of winds was to heap together the waters of the Channel between Bolt Head and Lizard Point, and drive them, with terrific force, into the narrow inlet of Plymouth Sound. This storm was not only greatly more violent, but of much longer duration than that of 1817. When the breakwater could be examined it was found that out of the 1,241 yards of the upper part, which had been completed with a slope of three to one, 796 yards had been altered as in the previous storm, and the immense blocks of stone which formed the seaface of the work had, by the force of the waves, been rolled over to the landward sides thus reducing the sea-slope, as before, to about five to one. The accuracy of Mr. Rennie’s view as to the proper slope—which was indicated by the action of the sea itself—was thus a second time confirmed;” and a board of eminent engineers reporting in accordance, the work was so finished. When the action of the sea had formed its own slope and had wedged together and settled the great mass of materials which form the breakwater, and when no further movement was apparent, but the whole appeared consolidated together, then the slope towards the sea was cased with regular courses of masonry, dove-tailed and cramped together, the diving-bell being brought into requisition for placing the lower courses. A lighthouse has been erected on its western extremity, and the work may be regarded as a magnificent success, worthy of a great maritime nation.
A third leading illustration of a magnificent breakwater is afforded at Portland, and it is deserving of particular mention inasmuch as all authorities agree that it was constructed with little or no waste of the public money. “In the mind of the inquiring tax-payer,” [pg 192]said our leading journal,[64] “breakwaters are always associated with millions of money thrown broadcast into the sea, in out-of-the-way bays and inlets, which even without these obstacles to make them more dangerous, the most distressed mariner would be particularly careful to avoid;” and the writer goes on to mention several which either ought not to have been attempted, or where extravagant expenditure has been incurred. “In such a woeful list of hideous failure and costly mismanagement, it is a comfort to perceive that the long lane begins to turn at last, and that from our now having one good standard to go by, we may hope for better things for the future. Portland breakwater is a really grand and magnificent work, and one of which the nation may well be proud if it is inclined to let bygones be bygones, and forget the many successive failures before it was able to attain so much.” Portland breakwater is the right construction in the right place, and before its erection the Roads afforded doubtful shelter to vessels in distress. One advantage it enjoys, that of possessing a splendid anchorage of stiff blue clay, and being free from rock or shoal from the island of Portland itself up to the very esplanade of Weymouth. There, too, was the stone on the very spot; steep and rugged heights for fortifications, a noble harbour for shipping, and rail communication with all parts. But all these advantages might have been ignored but for the formidable nature of the works constructed at Cherbourg. The port itself is about five hours’ steaming from the French Cronstadt it was designed, sub rosâ, to keep an eye upon. So, in 1844, the commissioners recommended that it should [pg 193]be made a grand fortified naval station. In 1847 an Act was passed authorising the construction of a breakwater, and in 1849 the foundation-stone was laid by the Prince Consort.
PORTLAND.