April 14, 180.]

around, and suddenly darting into and out of tunnels | abysses reaching down to Hades itself, might be on the borders of the lovely, lonely lake of Bourgy, encountered. Large lakes might be unbosomed, and then along the banks of the Arc-the rail- and rivers might come pouring through fissures in way train, in its progress from Paris toward Turin, the rock; and not only drown all the workmen, finally arrives at the little Savoyard village of St. but, rushing through the tunnel on either side, Michel. Here the railway terminates; and, con- overwhelm the valleys of the Dora and the Arc. signed to the very untender mercies of the shaky Fire itself might be encountered, and the workmen diligence, the traveller, after a drive of twenty-five suffocated with poisonous gases. These were some miles through the barren valley, reaches Lans-le- of the imagined and imaginary difficulties in the Bourg, at the foot of Mont Cenis; and crossing this way of the commencement and completion of the to Susa, there again takes rail, and on to Turin. In enterprise; but there were others of a much more a little more than four years hence, if no unforeseen practical, and therefore formidable nature to be event occur, this route will be materially changed, overcome. and voyagers giving St. Michel, with its dingy houses and bad dinners, the go-by, and continuing in the railway wagon up the banks of the Arc, will take a turn at Modane, ten miles up the valley, and instead of scaling the Alps, will go rushing through their stony heart.

The usual mode of making tunnels is by sinking vertical shafts or wells at convenient distances, and working through from one to the other. Here, however, that would have been utterly impracticable. It was found that at a distance of 722 yards from the mouth, a well must have been 1,000 feet in depth; at 3,000 yards, 3,593 feet; and at 6,333 yards, nearly half the length of the tunnel, a vertical shaft must have been 5,400 feet deep, - a well which by the ordinary processes would require nearly

The Arc, rising in the Alps near Mont Cenis, pours down the valley which bears its name, and empties into the Isere, near Chamouset. Near the little hamlet of Fourneaux, eight miles from St. Michel, the river makes a bend in a south-forty years to dig. In case the shafts were made erly direction. Upon the opposite side of the oblique, instead of vertical, they would have been Alps, in the valley watered by the Dora-Ripeira, almost as long as the tunnel itself. There was then the Dora very accommodatingly also makes a bend but one way to open this, and that was by attacking towards the north; and thus, at these two points, it at the two ends, the mountain at its two opposite the valleys of the Dora and the Arc, make the near-bases. But here arose another difficulty. How were est approach to each other in all their course. laborers to be supplied with air at a distance of more Here, in these two secluded little nooks, they seem than three miles in the very bowels of the earth? to have had a fancy for making each other's ac- In tunnelling by hand, fifty or sixty years would quaintance, and each here made advances as far as have passed away before the completion of this not merely propriety, but Nature herself permitted. work, and some more rapid process must be applied. But the rugged, frowning, unsympathetic Alps stood Steam, the ordinary motive power, requires fire to sentinel and barrier between them, and roughly generate it, and fire feeds upon air. It was evident rejecting their cooing and wooing, turned them that this could not be made use of, and that a new off again in different directions, each to pursue its motive power must be applied. A happy combinaown course toward the mighty sea. This barrier, tion of circumstances led to this result. skill, science, enterprise, and determination are rapidly breaking down, and before many years shall have passed, we may reasonably hope that the Dora and the Are, though not indeed permitted to mingle their waters together in joy, will be firmly and forever united in the bands of iron.

It was owing to this proximity of the two valleys at those points, that Fourneaux upon the French, and Bardonêche upon the Italian side, were selected as the entrances and termini of the great Alpine tunnel. It was found that a straight line between them and through the Alps would measure 12,220 metres, or 13,577 yards, about seven and seven tenths miles. Forneaux and Bardonêche were also happily situated for a convenient junction with the railways already constructed, and the geological character of the mountain itself was found to be a favorable one for penetration.

An English engineer, named Bartlett, had invented a perforating apparatus which, being set in motion by steam-power, drove a drill like a battering-ram against the face of the rock, in time making a hole deep and large enough to be charged with powder. Three Italian engineers, Messrs. Sommellier, Grandis, and Grattoni, were at about the same time experimenting upon compressed air as a motive power, with the immediate object of applying it to the propulsion of railway trains up a steep incline in the Apennines. It occurred to these gentlemen that, could a combination be made of their motive power and Bartlett's apparatus, the result would be precisely the machine for boring a tunnel through the Alps. The motive power would cost nothing, and instead of consuming air, would supply it to the workmen. Years of labor and of thought were expended in contriving, combining, and experimentIt was not until some years after it was decided ing; and the result has been the perforating mathat the tunnel should be excavated that the work chine, moved by common air compressed to one sixth was actually commenced. In and out of the Italian its natural bulk, and consequently when set free Parliament, by scientific men, professors, and lay- exercising an expansive force equal to that of six men, all sorts of objections were made to its practi- atmospheres, which are now working their way cability, all kinds of horrible possibilities were im- through the Alps at the rate of three yards a day. agined, as obstacles in its way. Rock might be The work was commenced by hand at Bardonêche struck of so impenetrable a nature that the keenest in 1857, and continued till 1861, when the perforatempered instruments would be battered and turned tors were introduced, after about 900 yards had aside without making upon it the slightest impres-been accomplished. It was not, however, until sion; so hard, that charges of powder, no matter how heavy would be blown from it, as they would from the mouth of a cannon, without detaching or even shivering the surrounding mass. Immense subterranean caverns and yawning chasms, and

1863 that the perforators entered upon the French side, the intermediate time having been occupied in erecting dwellings for the workmen, machine-shops, all the appliances necessary for such an immense undertaking.

the unscientific reader would fail fully to comprehend the structure and action of the powerful and delicate machinery here employed. Twenty iron pipes or tubes, giving the ensemble the appearance of a huge organ, stand upright at a height of thirty feet in the air; in these, by an oscillating motion, caused by the rise and fall of water, common air is compressed to one sixth its natural bulk. This rise and fall is caused by a series of pistons working in the tubes. As the piston ascends, it pushes the water before it, and this in turn compresses the air, and chases it into a reservoir. As it descends, a

Provided with a "permit " to visit the tunnel and inspect the air-compressing machinery, I arrived at Fourneaux on the afternoon of the 19th October, the permission being available for the following day. Formerly all visitors who presented themselves were freely admitted, but as the tunnel advanced farther and farther in its progress through the mountain, the danger attending the entrance of strangers, and the annoyance thereby caused to the workmen, rendered it necessary that some more strict rule should be adopted. At present permissions are granted but for the fifth and twentieth of each month, and then only upon application to the "Di-valve near the top is opened, through which the rezione Tecnica del traforo delle Alpi," at Turin.

Fourneaux, on the high road from St. Michel to Lans-le-Bourg, and about eight miles from the former, I found a miserable little village in a narrow part of the valley, built partly on the river bank, but principally upon the hillside. Nature here, wild and rugged as it is, is grandly beautiful. The Grand Vallon, beneath whose summit the tunnel is to run, raises its lofty snow-bonneted head 11,000 feet above the level of the sea into the sky. By the side of it is Charmey, its summit now also crowned with a recent fall of snow, which has whitened the branches of the mountain firs growing up to the very top. Down the mountain reach the firs and pines, darkly, almost blackly, green. Mingled with them are less hardy trees, their leaves ruddy with the hues of autumn; and fruit-covered barberry bushes, which give a rich variegated color to the hillside.

All around are piled up the Alps, rising one above the other; and at either extremity of vision, looking up or down the valley, it seems shut in by these eternal mountains. It was nearly dark, and the lengthening shadows were rapidly crawling up the mountain side, and departing sunlight was tinging the summits with that rich creamy hue which dying daylight impresses upon snow. I had but time to take a general view of Fourneaux and its surroundings when darkness, which sets in early in these valleys, came down and shut it out. A better dinner than I supposed could be obtained in the uninviting little auberge in which I had installed myself, and å bottle of tolerable Savoy wine, prepared me for a night of rest; and the mountain torrent of Charmey which came tumbling directly beneath my window, soon lulled me to sleep with its rude, monotonous music.

the

common air rushes to supply the vacuum, and this in turn is compressed and pushed into the reservoir. The pistons are worked by water-wheels; and thus one force which costs nothing is made to manufacture from the surrounding atmosphere a power which is now boring through the hardest rock.

From the reservoir an iron pipe eight inches in diameter, in sections eight feet in length, the joints being rendered air-tight by cushions of caoutchouc, and laid upon the tops of stone posts, conveys the compressed air along the roadside till nearly opposite the mouth of the tunnel, where, taking a sharp turn, it follows a steep incline, upon which a doubletrack railway is laid, up to the entrance. We followed the course of the pipe up this incline, upon which the " kangaroo wagons (so called on account of their peculiar construction, the two front wheels being made lower than the hind ones, giving the wagon the appearance of a kangaroo) were mounting, heavily laden with stone, cut for the mason-work of the tunnel. Four hundred and fiftyeight steep stone steps brought us up on a large artificial plateau, formed by the debris brought from out the excavation and shot down the mountainside.

Nothing seemed so surprising, and nothing could be so likely to astonish the general observer, as the fact that the mouth of the tunnel is at a distance of 105 metres, or 340 feet above the level of the valley. The reason, however, is evident enough when the facts of the case are known. The two opposite valleys of the Arc and the Dora differ in their heights above the level of the sea, the former being at an elevation of 1,202 metres and a fraction, while the latter has an elevation of 1,335. A line, therefore, run straight from the base of the mountain on the Bardonêche, or most elevated side, would emerge upon the Fourneaux side at a distance of 132 metres above the valley. This difference is to be compensated for, and it is done by commencing the tunnel on this side at an elevation of 105 metres, and giving a much steeper grade from the north end to the centre than from the other, the grade in the one case being 0.022 to the metre, and in the other but 0.0005.

The "Mont Cenis" tunnel, as this is usually called, is an egregious misnomer, Mont Cenis being distant at least sixteen miles from the French, and twenty from the Italian entrance. The line of the tunnel passes beneath three peaks, respectively called the " Col Frejus," the "Grand Vallon," and Col de la Roue," the first being upon the French and the latter upon the Italian slope, and the Grand Vallon at nearly an equal distance between the two. Mont Cenis, being the best known of any of the range in this vicinity, will doubtless Arrived at the entrance, I delivered my letter to continue to carry off the honors. In behalf, how-Signore Genesio, the director of the workmen, who ever, of modest merit, which, the poet says, "seeks the shade" (and if this be true, the Col Frejus should possess an immense deal of that valuable quality, as it has certainly sought out about the "shadiest" position in the entire valley), I desire to put upon record its claim against the recognized one of its loftier and more aspiring neighbor.

The first visit we made in the morning was to the air-compressing establishment, situated half a mile from the mouth of the tunnel, and on the banks of the Arc. Without diagrams, and even with them,

invited me into his bureau, where he called my attention to a caoutchouc coat reaching nearly to the heels, and which he recommended me to put on. We then went to the mouth of the tunnel, where, each receiving from the custodian a lighted lamp, attached to a wire about eighteen inches in length, we commenced our journey into "the bowels of the earth."

The entrance does not materially differ in appearance from that of ordinary railway tunnels. It is here built up and faced with solid masonry, and is

twenty-five feet three and a half inches wide at the base, twenty-six feet two and three quarters inches at the broadest part, and twenty-four feet seven inches high. A double railway track emerges from the mouth, and wagons loaded with debris were coming out; and others, filled with cut stones for the masonwork, drills, and other working utensils, going in. As we entered, the only light we could see ahead was a gas jet blazing in the distance.

we walked on we saw lights again, dancing like fireflies in the distance, and soon a party of rough, halfnaked, smoke-begrimed men, who loomed up in the fog like enormous giants as they approached, passed us on their way from work.

At a distance of 1,670 yards, or nearly a mile from the entrance, we came upon a little cabin, or barrack, built upon one side, and here my guide informed me that the completed portion of the tunnel Along either side of the tunnel there is a trottoir ended. Entering the cabin, and following his adof flagstones, upon which we walked, lighting a path vice and example, I gladly removed coat and vest, for our feet with the lamp which hung near them. covering myself again with the caoutchouc; and, The air-conduit is ranged along the side of the gal-picking and trimming our lamps, we darted again lery, while in the middle of the tunnel, between the into the darkness. Up to this time it had been two lines of rails, a canal has been dug, through which plain sailing, walking along with as little difficulty the gas and water pipes are conveyed to the end of or obstacle as on a sidewalk in a deserted street. the gallery. This canal is wide and deep enough to Upon quitting this, however, we entered the gallery afford a refuge for the workmen and a means of in corso di scavazione, that portion of the tunnel exit in case the tunnel should be filled by a fall of which, having been opened by the perforating mathe crumbling rock above. The masonry on either chines, was now being enlarged by the ordinary side was damp, and in many places little streams hand process. Here there was no longer any trottoir, came trickling through it, and it occurred to me and, picking our way over piles of rocks, which that in time this constant percolation must inevita- looked as though they had been thrown in confusion bly wear away the cement which binds the blocks by giants at play, dodging wagons passing in and of stone together, and undermine the vault. Over-out, passing groups of swarthy workmen, through head, the masonry is not visible, nothing being seen an atmosphere yellow, thick, and stifling, we at but a wooden partition, dividing the tunnel into two length came upon a group of men standing quietequal galleries above and below. The object of this,ly as if awaiting something, in front of a heavy which is only temporary, is to create a current, the oaken door, which closed the passage in advance of rarefied air from the lower gallery rising and rushing us. My guide said we must stop here for the presout through the upper, while fresh air comes into ent. I imagined the cause, and selecting the softest, the lower one to supply its place. As yet this par- smoothest-looking rock, sat down and meditated. tition extends only a short distance, and is not of much practical value.

We passed the gas jet, and looking before us, saw nothing but the most impenetrable darkness; and looking behind, I observed the entrance gradually growing smaller, until after I had continually turned and watched it till it had dwindled down to the apparent size of an apple, it suddenly dropped out of sight, as the sun sinks below the horizon in a calm summer sea. Peering then in either direction, I saw only impenetrable darkness. I use the word “saw" advisedly, for this darkness here in the bowels of the earth seemed to be palpable and ponderable, something more than what the philosophers define as a mere absence of light, something heavier and more solid than a negative,- a real positive entity, which it seemed to me I could feel pressing against and around me, as, guided by the flaring flame of our lamps, we forced our way through it. Upon inquiring of my guide how far we had reached, he called my attention to a little notch in the wall, where the distance was marked 1,000 metres, or about two thirds of a mile.

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Here was I, more than a mile from the mouth of the tunnel, with a mile of Alps piled above my head. The gallery was not more than ten feet wide and seven high, and its roof and sides were of jagged, sharp, protruding rocks, seeming to need but a slight shaking to send them tumbling down about our ears. Suppose they should tumble, and we be all buried alive in this hole in the earth! Suppose some of the predicted rivers or possible lakes should find their way through some aperture just opened, and engulf us now! Suppose the air-pipe should burst, or, worse still, the supply of air be stopped, and we all suffocated! Suppose- but the thread of my rapidly-crowding hypotheses was broken by a sudden sound which might well, under all the circumstances, have appalled a braver and more firmly constituted man, and which for an instant made me believe that one of my suppositions was about to become a reality. Bang! but not the sharp cracking “bang" of a heated cannon, or the sound of a rock-blast in the open air, - a dead, dull, rumbling explosion, which reverberated through the gallery, and seemed to give the whole earth a shake. I started, and involuntarily looked up, as if expecting to see the stony roof give way and tumble. Bang! bang! bang! in rapid succession five or six other blasts were blown; the oaken doors were opened, a huge gust of thick yellow smoke and stifling black gunpowder came rushing toward us, when my guide touched me on the shoulder and said we could now proceed. I uttered an inward "thank God!" that I was really safe, and speedily sprang up and joined him.

A dull rumbling sound attracted my attention; and in the distance, and seeming miles away, lights were dancing up and down in the murky air, as the feu follet, or wildfire, dances and flits in summer evenings over marshes, bogs, and fens. These were the lamps carried by some workmen going out, and a wagon loaded with debris soon came rolling by us. Up to this time I had experienced no particular difficulty in breathing, a sensation only that the air was unnatural and dank, like that in a cellar. As we advanced, however, it began to grow hot and Passing beyond the heavy oaken doors, still carestifling, and we entered a thick yellow fog, redolent fully picking our way over the stones through the of the fumes of gunpowder, which, indeed, it gallery, growing lower and narrower at every step, was, seeking its way towards the mouth of the tun-through the smoke we soon discovered a brilliant nel. This was very disagreeable, almost suffocating, blaze of gas, and heard a sharp hissing sound. Sudproducing a sensation of heaviness upon the brain, denly we emerged from the heat and smoke, and a dull headache, and a fearful feeling of dread. As were breathing an air fresh, sweet, exhilarating, and

doubly grateful to the lungs after the deteriorated material upon which they had been feeding. We were in the "advanced gallery" at the end of the tunnel, and before us was the affusto, bearing its nine perforators, persistently striking and boring their way into the solid rock, scattering around them sparks of fire struck off at every blow.

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A drill was attached by a flexible joint to the piston-rod; a workman standing upon the front end of the machine, held and directed this, as a gardener would the hose of a common garden-engine; the compressed air was turned on by another workman, at the hind end of the affusto, and the drill commenced its rapid and heavy blows upon its formidThe gallery here is not quite nine feet in width, able foe. Thud!” “ thud!” “thud!” it goes, at and but eight and a half in height. The affusto, as the rate of two hundred times a minute. Two men the huge structure is called upon which the per- mind this portion of the apparatus, one to give the forating machines are borne, and which bears pre- general direction of the drill, and the other, standcisely the same relation to them that the carriageing upon the ground, holds the end where it strikes does to the gun, nearly fills up the entire space. In the rock with a crooked iron, to prevent it from order to observe the action of the machinery, we flying off from the desired point of attack. The were obliged to coast carefully along the side of force of each stroke of the bar, is 90 kilogrammes, this heavy wagon, and when arrived at the front, to or 198 English pounds, and as the piston moves wedge ourselves between it and the rock, with just back and forth, and consequently causes the bar to space enough to stand in. strike the rock at the rate of from 180 to 200 times a minute, each drill, therefore, exercises upon the point of attack, a force equivalent to 39,600 pounds a minute.

Here the sights and sounds really became cheerful and pleasant. The gallery is brilliantly lighted; the compressed air, a jet of which is constantly escaping from the conduit pipe, is fresh, cool, and grateful to the wearied lungs; the constant rapid "thud" of the drill as it strikes the rock; the hissing sound of the escaping air; the cries of the workmen to each other, sounding unnaturally loud in this pure air and confined space, all constituted a scene as exciting as it was strange. A feeling of manly pride, at the sight and action of these wonderful machines, in the operation of which the powers of nature are made the slaves of man, seems to invade the soul. We forget that we are more than a mile from daylight, and that four thousand feet of Alps are weighing above our heads. We forget danger and banish fear; and the workmen, thirty-nine of whom are employed upon each affusto, seem to have no idea of either. They perform their labor in this little hole, with a remarkable sense of security. They seem to play with these huge machines, they put their hands upon and direct the steel bar which strikes the rock, and the powerful instrument which pierces the Alps glides between their fingers like a child's toy. They hop about | like toads between the drills, perch themselves upon and under the various parts of the monster machine, and never seem to dream that at any moment, some unknown, unlooked-for fissure in the rock may be discovered, and they crushed to atoms by the tumbling mass; or that this powerful agent, which they have made their slave, with its explosive force of six atmospheres, may some time burst its iron fetters, and scatter death and destruction around it. Each perforator, nine of which are at work, is entirely independent of every other, so that, when one is placed hors de combat, its inability to act does not affect the rest. It is much easier to describe the operation of the perforator and its effect than the complicated machinery by which it is set in motion. The motive power is conveyed to it from the conduit by a flexible pipe, which throws the compressed air into a cylinder placed horizontally along the affusto. In this cylinder a piston works back and forth, and to this piston is attached a fleuret or drill, about three feet long, finely tempered and sharpened at the end. As the piston moves up and down, it of course drives the drill against the rock, and interdraws it, and by a very delicate and complicated piece of machinery a rotatory motion, similar to that in hand-labor, is given to the drill itself. We arrived in the "advanced gallery" at a very favorable moment, just as a new attack was about being commenced by a perforator.

The rock upon which the perforators were at work when we entered was hard white quartz, the most difficult to pierce which has yet been encountered. This layer was struck in the middle of June last, and its presence has materially retarded the progress of the tunnel. Formerly, in the mica, hornblende, slate, and limestone, through which they quarried, the perforators made an advance of from one and a half to three yards a day. In this quartz, they now make but from eighteen to thirty inches. A few figures will exhibit the rapid and decided reduction in the rate of progress. In May last, the advance was 91 metres; in June, when the first croppings of the quartz began to appear, it was reduced to 494; in July, to 16; in August, to 13; and in September, to 194 metres. It is supposed that there still remains a year's work in this quartz.

In commencing a perforation, the first difficulty is making a hole sufficiently large to confine the drill. When this first strikes the rock it hits wide and wild, like a pugilist blinded by the blows of his adversary. When once fairly entered, however, it works back and forth and rotates with great precision and regularity, a stream of water being conveyed into the hole by a flexible pipe to facilitate the boring. The nine perforators are placed above, below, in the centre, and on the sides of the affusto, so as to attack the rock at different points and angles, upon a surface of seven square metres. About eighty holes in the ordinary rock, from thirty to forty inches in depth, and varying in diameter from an inch and a half to three inches, are thus bored in preparation for blasting. In the quartz, however, in which the boring is now in progress, the holes are made but from seven inches to a foot in depth. Eight hours is usually employed in the boring, and this being completed, the affusto is drawn back, and a new set of workmen, the miners, take possession of the gallery. The holes are charged with powder and tamped, the miners retire behind the oaken doors, the slow match is ignited, an explosion occurs, which sends its reverberating echoes to the very extremity of the tunnel; the rock blown out is cleared away, the affusto is advanced again, and another set of workmen coming in, the perforators are set in motion.

And so this continues year in and out, week days and Sundays, night and day. The thousand workmen employed upon either side are divided into three reliefs, each working eight hours and resting

sixteen. But two days in the year, Easter Sunday | yards- nearly a mile and a half- from the enand Christmas, are acknowledged holidays. And trance. Up to the end of September last the adfor this constant, difficult, and dangerous subterra-vance made upon the Italian side was 2,914 metres nean labor, accompanied with an oppressive heat and a poisonous atmosphere, with smoke and grime and dirt, the common laborers receive but three franes a day, the more important and experienced ones four and five.