ACROSS THE ANDES.

Otago Witness, Issue 1162, 7 March 1874, Page 7

ACROSS THE ANDES.

{The Tli lien.)

A correspondent of the New York Times has supplied to that journal au account, propared after recent personal examination, of the progress of the great Sonth American Railroad over the Andes. It commences at Callao, on the Pacific coast, and after beinjj carried 105 miles to Summit Tunnel, which is upwards of 15,000 feet above the level of the sea, descends, or is to descend, 31 miles more to La Oroya, a town on the eastern slope, whence it may be continued to the head of navigation on the Amazon or to the Atlantic coast. On loiving Callao, the road runs along the fertile valley of the Eimac, a small mountain stream. After some 30 miles, the mountains draw together ; along their sides are seen the ruins ot the old Inca days in rows of terraces and bare adobe walla, marking where busy towns once stood. Soon after passing Sfc B\rtolome, 47 miles from Callao and nearly 5000 feet above the sea, tho engineeiittg becomes difficult. Tho valloy is so narrow and steep that a retrograde is neoesR&ry to obta'ii elevation, and as there is not r n>'in for a curve, the road takes the shape of a V, at the apex of which is a turn-table, thus allowing the engine to be turned round and back on a side track to the rear of the train, which now becomes the front. Retrograding, though on an ascejading scale, the train, after travelling some three I miles, again comes opposite the depOt of San | flartotome, though now it is some 600 feet above the station, and moves on along a staep mount tin side until the bridge of the Acua da Verrugas is reached. The viaduct consists of four deck spans of the Fink type of truss, three of which are 100 feet long, and one, the central span, 125 feet in lenarth. The spans re3t on piers built ot wroughtiron columns, and these piers are 50 feet long by 15 faft wide on top. There being three piers, the total length of the viaduct; is 575 feet. These piers are the great foa*ure- of interest, and ire, respectively, U) fee 1 ;, 252 feet, ar.d 187 feet liii»h. Each pier consist* of 12 legs, which in plaD form a rectangle, arid the legs are composed of a series of wrought. juwß m w^Bifut coJuwye in loigths

of 25ft., connections being made up by castiron joint boxes, having tenons on each end running into the column. The tenons and the face of the casting against which the column bears are machine-dressed so as to face. The columns have an exterior diameter of 12 inches, and a diametez-, including flanges, of 16 inches. The legs of the piers are securely fastened together by three systems of brace-rods running transversely, longitudinally, and laterally, andbracedupby longitudinalandtransversemmshutes. These braces and shutes are connected at the joints by bolts and small pins. Transversely, the pin has the shape of an inverted W, two legs batter in and two out, the outer lega having a batter of one loot in twelve, and the inner legs being so inclined as to make the | above-mentioned shape. There are three of these Ws in a pier, each containing four legs, thus making 12 legs in all. The piers were raised within themselves, tier upon tier, the material being drawn by a common windlass. The side spans were raised with the usual scaffolding, but the central span, having been put together on a staging a few feeb above the ground, was lifted bodily a distance of 250 feet. This method is said to be a quicker and more economical one than any other, as a single span of masonry would have cost tsvice as much, and not been so safe. From this Verrugas viaduct the road winds on along the mountain side to Lurco, 56 miles from Callao, and G6s'> feet high ; the road working its way through an infinite ami ever- changing variety of scsnery — wild, cold, and forbidding — on toward the summit. It crosses the ravine of Challapa upon a bridge, in length 324 feet, and height 120 feet. This bridge is of French manufacture. Beyond it the road passes through an extensive cut in the solid rock, which opens on the valley of the Matucana. Here tie valley narrows until it becomes a gorge, and amid an intricate network of precipices, ravines, toppling crags, and cold, cheerless, and rocky peaks, the engineers have threaded their way, bridging tunnelling, and delving around or through obstructions that seem impassable, until they have brought the road-bod up an ascension of 3000 feet in 15 miles, thus reaching San Matoo. Beyond Ban Mateo, the valley of tlie ]<,imac rises 1300 feet in four miles, and the Falls of lafiermllo, or Little Kill, bar the further ascent by this route until it is passed, thus forcing a detour around it, the ravine of the Parac being used to accomplish it. Thus on and upward the road winds, until, having reached an elevation of 15,045 feet, it passes the summit through a tunnel 3000 feet long, and emerging on the eastern slope, winds down to La Oroya, on the Atlantic side of the Cordillera. In this great work engineering Bcience has smoothed down the vuggedness of nature, and man has triumphed over matter. The tunnel cuttings reach an aggregate length of over three miles, and there are 30 bridges and viaducts, besides innumerable culverts. The road will open a way for the products of the agricultural region lying on the eastern slope of the Andes to the seaboanl cities of Peru, and also affords means for the rich miueral deposits lying in the district between San Mateo and the Summit to be developed, which their isolatedneso has heretofore precluded. Already trains run beyond Lurco. The road-bed is in part laid up to the Summit tunnel, and on the slope that leads down to La Oioya. It is expected that 15 or IS months more will suffice to complete the road, and the former toilsome, dangerous, and wearying journey of a week '. will be reduced to the easy jaunt of a clay. ' The road is a Government enterprise, and belongs to the nation of Peru, the work be- ■ ing performed under contract by Henry [ Meiggs, the Railroad King o f South America. ■ Although but 13li miles long, the road has : caused a groat expenditure of labour and : life, the latter partly from a reckless uso of spirituous liquor.- 1 , ai.d partly by fevers pro- 1 vailing in a narrow belt of territory.