Discoveries and Inventions of the Nineteenth Century

to command it. Unforeseen difficulties may arise to thwart the plans, but the enterprise, so far, is full of promise. The opening of such a communication between this country and the Continent will be a pure gain to the commercial and social interests on both sides. It obliterates the Channel so far as it hinders direct communication, yet keeps it intact for all those advantages of severance from the political complications of the Continent, which no generation has more thoroughly appreciated than our own. The commercial advantages of the communication must necessarily be beyond all calculation. A link between the two chief capitals of Western Europe, which should annex our railway system to the whole of the railways of the Continent, would practically widen the world to pleasure and travel and every kind of enterprise. The 300,000 travellers who cross the Channel every year would probably become three millions if the sea were practically taken out of the way by a safe and quick communication under it. The journey to Paris would be very little more than that from London to Liverpool. It is, however, quite needless to enlarge on these advantages. The Channel Tunnel is the crowning enterprise of an age of vast engineering works. Its accomplishment is to be desired from every point of view, and, should it be successful, it will be as beneficent in its results as the other great triumphs of the science of our time.” The Channel Tunnel is not yet a fait accompli, although the preliminary trial works have been made at both ends. Drift-ways of some ten feet diameter have been cut beneath the waters of the strait, and instead of the experimental half mile mentioned in the foregoing paragraph, the works have been pushed forward on the English side for about a mile and a quarter with complete success. As was anticipated, no physical difficulties were met with, for the machines did their work with the greatest ease, and the drift has now remained for some years practically free from any infiltration of water. These results indicate that the scheme might be completed with speed and safety. Parliament, however, 371has refused to allow the undertaking to proceed, being moved to this course by the opinions of military authorities, who see dangers to England in the completion of this enterprise, or at least such a disturbance of the British complacency at the notion that our island might be reached otherwise than “by the inviolate sea,” that the whole land would be liable to terrors and alarms from invasion by stratagem. It is represented that huge fortresses and a special army for that purpose would become necessary to guard the mouth of the tunnel were it made. This is, perhaps, the kind of objection which such an enterprise could not fail to raise. But it can hardly be expected that all the commercial and international advantages which the realization of the scheme would undoubtedly secure are for ever to stand in abeyance for such opinions as have, for the present, caused the operations to be suspended. It has been pointed out that there are many ways of instantly rendering such a tunnel impracticable in case of a sudden alarm. But the necessity could only arise after a supposed paralysis or destruction of such army and navy as Britain could bring together to defend her land. Perhaps military skill will presently devise less costly methods of defence than those authorities now suppose the tunnel would require; or, even if such armaments were really necessary for our sense of insular security, the expense might be no unprofitable outlay for the advantages to be gained. It is satisfactory to know that the promoters of the scheme are sanguine of the subsidence of the military and political prejudices, which are now the only obstacles to its accomplishment. A somewhat unexpected result from the operations in connection with the experimental driftways has been the discovery, on the Kentish coast, of seams of coal underlying the chalk at a workable depth. THE ST. GOTHARD RAILWAY. Since the completion of the Mont Cenis Tunnel, a still greater piece of rock boring has been begun and finished in the great tunnel of the St. Gothard Railway. The construction of a railway to connect Italy with Switzerland, was a project conceived as far back as 1838, when the first railway company in the latter country was constructed. The route of the proposed line was a matter of much debate, not alone on account of difference of engineering opinions, but also by reason of the various competing interests that would have to be reconciled and induced to co-operate in the work. The St. Gothard route was only one of the several schemes that were advocated, and the first decisive step appears to have been taken at Lucerne, where, in 1853, a meeting was called by the authorities of the canton to consider the merits of the project; the result being that the Lucerne Government addressed to the Federal Council a representation of the advantages this route would afford. More discussion ensued, and it was only when Switzerland appeared likely to have no share in the traffic between the Milan district and the more northern parts of Europe that, in 1861, the partizans of the St. Gothard route appointed a provisional committee to take action in the matter. This committee had plans prepared, and sent a deputation to obtain the assent of the Italian Government. The canton of Tessin, through which 373the projected line, or its then surviving rival, was designed to pass, became a lively scene in the game of speculation, for promoters rushed in to secure, if possible, concessions which they might sell at a very advanced price to the winning party. For this purpose came to that poor Swiss canton Jews and Christians from every land. The St. Gothard route gained the day, and a Union was, in 1863, formed by the concurrence of the two principal Swiss railways and fifteen of the cantons most interested in the scheme. Difficulties and delays were, however, encountered before the necessary compacts could be concluded with the neighbouring states—and then there came the war of 1867. So that it was not until the latter part of 1872 that the construction of the line was actually entered upon. Before the great work of piercing the St. Gothard had been completed, the undertaking was embarrassed by financial difficulties arising from the fact of the lines on the Italian side costing more than double the estimated amount. The Swiss Government, however, voted a special subsidy, and the work, which had been suspended for a while, was proceeded with; much attention being paid to its economical prosecution. In 1881, when the line was opened, the mails were carried between Zurich and Bellinzona in seven hours, instead of in thirty hours as previously required for transit by the excellently appointed mail carriages under the Federal Administration. Fig. 187a.—Map of the St. Gothard Railway. Besides the great tunnel, the St. Gothard line has some unique devices in railway construction which cannot fail to interest the reader. Several of the passes over the Alps have been made use of from time immemorial. We know that Hannibal led his Carthaginian hosts over one of them, and that they have been traversed by Roman legions, as well as by Germanic hordes. But, although the St. Gothard is the most direct of all the routes, it never afforded a passage to armies or migratory tribes. The road through this pass was not formed by the use of any elaborate appliances for overcoming the natural obstacles: it was rather the work of simple peasants and mountain shepherds, with such rough constructions in wood as might give a sufficiently secure passage across the torrents and gorges. The old road keeps beside the Reuss from the head of the lake of Lucerne until it reaches the highest level of the pass, where the water-shed occurs. It then descends steeply, with many twists and windings, to the banks of the Ticino, and it follows the course of this river to its embouchure at Tresa, on Lago Maggiore. The railway follows the same course, except that it cuts off the higher part of the pass by the great tunnel piercing the mountain. The scenery throughout could, perhaps, be nowhere equalled for the variety of its wild grandeur. The great tunnel of the St. Gothard passes from Gœschenen, on the Reuss, beneath the col of the pass, and emerges close to the village of Airolo, on the banks of the Ticino. The length of this tunnel is rather more than nine and a quarter miles, so that it is about one and a half miles longer than the Mont Cenis Tunnel. Its northern end is 3,638 feet above the sea level; its southern end is higher, namely, 3,756 feet; but there is an intermediate point in the tunnel higher than either-–3,786 feet—and from this there is a uniform incline in each direction. The tunnel is 300 yards beneath the lowest part of the valley of Andermatt, and the summits of the mountains it traverses are at least a mile above it. The motive power by which the rock-drilling machines used in driving the tunnel were actuated was, as in the case of the Mont Cenis Tunnel, 374compressed air; and the power used for compressing the air was, in this case also, a head of water,—but this was not applied in the same way. The waters of the Reuss at the northern side, and those of the Tremola and of the Ticino at the southern side, were taken at a considerable height in very large cast-iron pipes, and were made to act upon powerful turbines that gave motion to the compressing machines. These were capable of compressing the air so that its volume was reduced to one-twentieth, and the pressure it then exercised would, of course, be equal to that of twenty atmospheres, or about 300 lbs. on the square inch,—or more than three times as much as was made use of in the Mont Cenis Tunnel. The compressed air, carried through pipes to the head of the workings in the rock, was there allowed to exert its force on the pistons of the perforators in the manner already described. There was, in fact, a continual repetition of exactly the same cycle of operations of boring, charging, firing, etc., that are mentioned on page 355. A large quantity of the compressed air was always allowed to rush into the work immediately after each blasting, in order that the smoke and other products might be driven out and the atmosphere rendered fit for respiration. In attacking the mountain simultaneously from each side it was, of course, essential that the tunnels should be driven in precisely the same direction, and therefore the positions of the points of departure had to be determined by very careful surveys. At Gœschenen, the gorge of the Reuss did not naturally admit of a sufficient distance of vision to fix the direction with the required accuracy, and it became necessary to pierce a thick mass of rock with a special tunnel for the purpose of taking a sight sufficiently far back. At Airolo, again, the tunnel had to enter the valley by curving towards the village; and here a provisional gallery had to be driven in the straight line. PLATE XVI.THE NORTH MOUTH OF THE GREAT TUNNEL, ST. GOTHARD RAILWAY. Several contractors competed for the work of constructing this great tunnel, and it was at first supposed that an Italian company, which was managed by some of the principal engineers engaged on the Mont Cenis, would be almost certain to obtain the contract. The promoters, however, intrusted the work to a private individual, M. Louis Favre, of Geneva. This gentleman undertook to complete the tunnel in eight years, at the price of 2,800 francs per mètre for the work of excavation merely, exclusive of masonry, etc. This cost would be not far from £101 per English yard. The contract was signed