Rensselaer Union, Volume 7, Number 28, Rensselaer, Jasper County, 1 April 1875 — Tunnels. [ARTICLE]

Tunnels.

There are at present about eighty miles of tunnel in England, the longest passage, of 5 500 yards, being at Huddersfield. The longest in France, on the St. Quentin Canal, has a length of over 13,000 yards. But the English distanced all’ competition in that line when they built the Thames Tunnel. The idea of this originated in 1798, when Mr. Ralph Dodd proposed to make a way under the river between Gravesend and Essex. In 1804 Mr. Trevethick made a trial on the present site of the tunnel. He made a passage five feet high and three feet wide, and this he had'carried nearly across to W apping when the river broke in and spoiled the experiment, throwing such a quantity of cold water on the project that the English became disgusted and would have no more of it. They felt uncomfortable just then, knowing that the united fleets of France and Spain were ready to try conclusions with Lord Nelson in the chops of the channel. .But in 1826 thepassage between Rotherhithe and Wapping (about a quarter of a mile across) was again attempted, under the guidance of Mr. Brunel. In 1827 the water burst in, in spite of the •caution with which the shield was advanced, and the labor was suspended for a time. In 1828 a like accident occurred, and six mon were drowned. After this the work ceased for seven years. It was renewed in 1835, and continued till the passage was completed It lies sixteen feet below the bed of the river, and is 1,200 feet long between the shafts [on either bank—that is, something about a quarter of a mile. It has two arched ways, each sixteen and a half feet high by fourteen feet wide, with a wall between them. It cost about £500,000, and was never remunerative, being only used by pedestrians, who paid the toll of a penny, and furnished just enough to keep it in repair. In 1865 it was sold to the London Railway Company for £200,000, and is used as a connection between their roads running on the northern and southern sides of the Thames. The tunnel was in fact a failure, and in time to come a better one will no doubt tie built near that locality—one that will allow the passage as. heavy trains or wagons. In 1869 another tunnel was carried under the Thames at Tower Hill, and completed in a year at the cost of £20,000. This allows the travel of omnibuses. Another (a land tunnel) has been made* in Arthur street, and another from Poplar to Greenwich. Along with these Lopdon has dug three and a half miles of tunneling for its great subterranean railway, and will probably dig a great many more. So that, if it cannot boast of its catacombs, like -so many other great cities, it seems bent on making up the subterranean deficiency in another and_ more utilitarian way.

Fourteen years after the opening of the Thames Tunnel the Governments of France and Sardinia encouraged the far grander enterprise of a passage through the Alps under the height of Grand Vallon near Mont Cenis. The idea of this was afloat in 1841 when Joseph Medail, of Bardonneche (the Italian end of the tunnel), proposed to pierce Mont Frejus. In 1857 it was decided that the way should run under the Vallon, from Modane, on the upper side, to Bardonneche, on the Italian—a subterranean distance of seven miles and a half. Count Cavour warmly patronized the undertaking, and the cutting of the sod at Modane in the above year, was witnessed by King Victor Emmanuel and Prince Napoleon. As the height of the Grand Vallon did not permit any intermediate shaft-sinking, the labor was be gun and carried on from the two ends toward the center. The work of boring was done in the old way, by hand, till 1861, when the engineers—Sommeiller, Grandis and Grattoni —devised a piece of machinery set in motion by compressed air, acting with a force of five atmospheres through a piston in a cylinder. With this half a dozen borers were driven simultaneously against the rock and the advance was ten times as fast as before. In 1866 half of the distance had been excavated and in 1870 the workmen, meeting at last, shook hands through an opening in the tunnel. In 1871 the way was opened for travel after the labor of fourteen years. This £reat achievement encouraged men to hope for the removal of other Alpine difficulties, and at the present time another railway tunnel is making its way under the heavy mass of Mont St. Gothard. In our own country the necessities of travel and trade have originated a great many tunnels, the most remarkable of which is the passage through mica slate and quartz rock under the Hoosac Mountain, eighteen feet high and fourteen feet wide, and about 24,000 feet, or four and a half miles, long. But the greatest tunnel idea of modern times, or any other times, is the proposed passage under the strait between Dover and Calais, which will, or would, have the effect of renewing more intimately and far more profitably the ancient intercourse between France and England—an intercourse for ages of mutual, jealousy and war, leading the people on either side to look on those on the other as “ natural enemies”—to use the very British expression of that especial Briton, Charles James Fox. But nature has no part in the antipathies which grow up between near neighbors, and Napoleon was wise enough to understand his geography. In 1802 he encouraged the plan of M. Mathieu to unite the two countries by a tunnel, or something like a floating bridge, after the manner of the potygomphon odisma, or floating] causeway, built once upon a time by King Xerxes across the Hellespont. The idea was rather a wild one for that tijne, but Napoleon, who had no hatred of the English, favored it, taking occasion to say that England and France united could be masters of the world—a “ Napoleonic idea” w r hich subsequently influenced the policy of his nephew., Napoleon 111. But the fierce wars came instead of the viaduct. In more peaceful times, over fifty years ago. MM. Teseie de Mottray and Franchot suggested the laying of a huge cast-iron tube in sections along the bed of the strait between the French and English coasts. Another proprietor, M. Payerne, proposed a scheme of vast moles from each side, and a long bridge of solid masonry in the middle, strong enough to cope with the elements of that stormy channel. The Englishmen, Winton, Colburn, Chambers, Cowan, Page and (others, were rather in favor of Mottray’s i plan of laying down the huge tubes of east-iron, while many others contended for the long bridge, with enormous piers and openings at invervals for the passage of ships. . For many years this great idea has been agitating the minds of French speculators and engineer?, and at last a balance of possibilities has resulted in a decided purpose. On the 24th of last January M. Calliaux, French Mir.-

ister of Public Works, introduced into the Assembly a bill for the formation of a tunnel under the Strait of Calais, naming it a Projet d* Utilite Publique. This bill was passed. The application for the concession has been deposited with .the Government, and signed by Michel Chev-. alier, C. Bergeron, Paul Christofle, Lord R. Grosvenor, Sir W. Howes, F. Kuhlemann, of Lille, P. Talabot, Thome de Gamond and other men of note and influence. Under the bill two bodies, composed of capitalists and engineers, have been associated, one to act in England and the other in France, each to carry on from its own side a series of surveys and explorations preliminary to the main undertaking, and each company is to work on its own capital of 2,000,000 francs, or over £BO,OOO sterling. The French company is the Societe des Etudes, administered by a committee of which M. Chevalier is Chairman. Already Messrs. Rothschild have subscribed onequarter of the capital on the French side, and the French Northern Railway Company one-half. of the same. On the English side Sir John Hawkshaw is the engineer-in-chief, and the Southeastern & London and the Chatham & Dover Railroad Companies are largely interested in the enterprise, as they well may be, while Mr. Brunton, the well-known engineer, has invented a new borer which will do even better than that used in the Mont Cenis Tunnel. On the French side, M. Lesseps, constructor of the Suez Canal, is ardently engaged in the course of the Strait Tunnel, and has recommended it in an address delivered before the Academy of Science. Indeed, the Frenchmen are more entetees on this matter than the English, believing they would be the greatest gainers by the achievement. The two preliminary companies will now proceed to survey the road they mean to travel. They already know, of course, the sounding of the strait between the Bay of St. Margaret, near Dover, and Sangatte, near Calais, a distance of about thirty-two miles. These soundings vary from about eighty to 180 feet. But the nature of the formation under the channel at a depth of 200 or 300 feet is not known; and this must be ascertained. If the hard-pan of the bottom is chalk, like the formation of the land on the sides, the projectors will have solid encouragement to proceed. If, on the contrary, the bed of the strait should be of sand and alluvial earth to a depth of 300 feet and more, they would scarcely attempt to make a tunnel over thirty miles long through such a dangerous medium. This is the uncertainty; and to solve the matter will be the first duty of the companies. To that end each will sink its own shaft on its own shore to a depth of 800 or 400 feet, sufficient to show whether or not the land stratum of chalk extends downward on each side beneath the channel of the strait. Should it be found to do so on both sides it would naturally be concluded that the chalk is in the middle also, to furnish a solid roof for the excavation, and not stich a sandy' roof as broke so disastrously into the works of the Thames Tunnel. For this experiment the companies are sinking their respective shafts and gaieties d'essai, or trial-galleries. It is estimated that the cost of the tunnel would be 100,000,000 francs, or about £5,000,000 sterling, and that the work could be completed in three years. The French are highly interested in the project, since they lie in the track of a great railway such as will yet connect England with the Euphrates and Hindostan. The English are cautiously inquiring about the ventilation of such a tunnel. But it is considered that the Hawkshaws, Brasseys, Lesseps and other men of science who advocate the scheme would not do so if a sufficient current of air could not be maintained in the passage. At any rate this subject will be investigated by the two preliminary companies.

A talk about tunnels (in esse or posse cannot well conclude without some allusion to another which would enable New Jersey to “ cast out her shoe,” Scripturally speaking, over the profitable Island of Manhattan, and be an achievement to throw into the shade its diminutive precursor of the Thames. The company proposing to construct this passage, about a mile long, from Fifteenth street in Jersey City to Christopher street in New York, has got its sanction under a general railway law of the sister State, and its prospectus and plan have been made known to the public. Meantime, as an injunction has stopped the work in limine, there is as yet no real progress to report. But the Hudson Tunnel will be a great fact some day, and that no very distant one. In a few years New York*will have its rival wonders of engineering skill to exhibit—-her gigantic bridge of the East River above and her tunnel of the Hudson below; two art achievements which will be somewhat in keeping with the natural grandeur of our harbor and give the city a metropolitan dignity worthy of its wealth and ihevitable expansion.— N. Y. Times.