Page images
PDF
EPUB

The projector of one of the schemes for a submerged tube proposes to build it in one length on shore, and then to float it out to sea, and drop it at one dash. Poor Brunel should have been alive, to have either witnessed or had a hand in this magnificent engineering scheme, which far surpassed any of his own. Imagine the triumphant attitude of this engineer, wielding a tube only about twenty miles long, and for the moment of submergence, at least, ruling the waves between England and France! His task accomplished, however, poor travellers would not have been much benefited, inasmuch as he proposes to have the two ends of his tube made solid, and entered from either shore by chain piers, or by a small steamer!

The enthusiastic gentleman who suggests the arched roadway on the bottom of the strait proposes to construct it by the agency of forty subaqueous boats, and 1,500 sailors and navvies-sub-aqueous also, of course. The projector of the bridge would build 190 piers in the Channel, 300 feet square at the bottom, rising to 150 feet square at the level of the sea. On these pedestals he would build towers, 100 feet in diameter, 260 feet high; connecting his chain of towers with a tubular bridge far above the topmost truck of our tallest "admiral.” When we remember that the mid-channel is about 160 feet deep, and that, say, at least 40 feet would be necessary for foundation, these mammoth towers would be about 460 feet high, rising from a base of 300 feet. Remember, good reader, our engineer does not project one of these

pyramids to be constructed in a restless sea-way,

but 190!

Mr. Chalmers is jocular enough at the expense of the schemes of his predecessors, but there are a few items in his own which require explanation. His

[graphic][merged small]

plan is a tube reaching from shore to shore, in the still depths of the Channel. As this tube will have a powerful tendency to rise, it is to be weighted with iron boxes filled with rough stones, the whole to be

K

covered with an embankment of stones, which will form a ridge from shore to shore 150 feet wide at the base, 40 feet high, and from 40 to 120 feet below the level of low water.

This tube is to be enlivened with three ventilators, one in mid-channel, and one about a mile from either shore. As the tube is to be 18 miles in length, passengers will never be further from the light than 4 miles. But an excursion-train, or perhaps half a dozen, within three minutes of each other, would possibly find themselves hard-up for breathingholes, like the poor frozen-in seals sometimes in the Northern regions, so the projector proposes a system of artificial ventilation, by up and down draughts, such as we already have in our coal-mines. The necessity for such an adjunct is obvious enough, but it certainly is not calculated to give any favourable view of this new trajectus. But schemers are ever sanguine, and in the very weakness of his case he sees nothing but strength. One would think that a passenger would shut his eyes and rush under the roaring waters of the Channel with some such feeling as Schiller's diver ventured after the golden cup-only too glad if he came to the upper world all safe and sound. But no, Mr. Chalmers must make him absolutely enjoy both the prospect and his sensations!

The cleanly painted light-coloured iron, and a thousand double lamps, one every thirty-five yards, will give a cheerful aspect to this ocean roadway, and render it an agreeable contrast to the noise and damp and darkness of an ordinary tunnel, or even the miles of

uninviting scenery that often meet the eye in broad daylight. The noise in the tube can be reduced to a minimum; unlike tubular bridges suspended in the air, the sound and vibration of the iron will be deadened and neutralized by the equability and elasticity of the pressure without; and as the situation of the roadway will admit of a perfectly united rail, the sensation that travellers will experience on entering the Channel railway will be akin to what we feel after walking on a gravelly road with thin shoes, when we step upon the downy sward of a smooth green lawn.

Such a

We really must congratulate Mr. Chalmers upon his project for providing the nation with a new source of pleasure. People may, perhaps, in future take a turn in his tunnel as they now do in a Turkish Bath, for the purpose of calming irritable nerves, or for ascending into that seventh heaven of dreamy delight which the shampooing process produces. delicious place of meeting as this tube will afford cannot be overlooked for State purposes. After the next great war with France, and the next frustration of Napoleonic schemes, there will of course be a new Tilsit meeting between her Majesty and Napoleon in the neutral ground at the centre of the tunnel, and here, surrounded with the charming prospect of "cleanly painted light-coloured iron," with old Neptune playing Peeping Tom, perhaps, down the central ventilator, vows of amity for all futurity will be exchanged. Really, rose-coloured Mr. Chalmers, there is some such a thing as over-proving one's case.

We are by no means disposed, however, to employ our pen simply to disparage the efforts of those who are working in advance of their age. We confess we

believe in the ultimate accomplishment of a land passage under the English Channel. There is no part of that Channel, be it remembered, so deep but that St. Paul's Cathedral planted there would stand up head and shoulders out of the water. We know there are no great irregularities of bottom, for the first electric cable ever laid, without special care or knowledge, remained in perfect order for ten years, and when taken up the other day for repairs was found nearly throughout in as perfect a condition as when it was first laid down. This is Neptune's testimony to the calm condition of the water and the goodness of the bottom, and where a flimsy cable could remain so long a perfect pipe, able to resist all the efforts of one of the most subtle principles in Nature to escape into the surrounding water, surely a tube of iron could be found equal to maintain a free passage for man himself. The difficulties are all comprised in getting the tube once there.

Mr. Chalmers may well laugh at the idea of building a tube twenty miles long on land, projecting it like a large beam across the Channel, and then dropping it; but how does he attempt to get over the difficulty? He tells us he proposes to make his tube in lengths of 400 feet and 30 feet in diameter, and of joining them under water. He gives us, indeed, the most minute directions as to the manner in which these huge masses of iron are to be floated out and then sunk so that they shall be jointed together impermeably to the surrounding water. read his scheme it would really seem as though the

To

« PreviousContinue »