A striking evidence of the distance saved by the railway is afforded between Mendoza and Upsallata station. As the crow flies the distance is 40 miles due east; by rail it is 17 miles farther; but by the old mountain road which converges upon the line at Upsallata it is no less than 100 miles! The latter makes a wide, sweeping detour after leaving Mendoza in order to avoid the foot-hills, and to ensure an easy gradient for animal traffic. The wildest part of the range is encountered when the Mendoza River is left and the railway enters the Amarillo, or Yellow Gorge. Incidentally, the line through this rift was one of the most costly and difficult sections to build. Las Cuevas, at an altitude of 10,388 feet, was the objective, and so great is the difference in level within a few miles that some daring development work had to be carried out. The first sign of this steep climb is a Meiggs V-switch. The rack was adopted more extensively, this being introduced between short stretches of easier grade or sections of level, so that the railway really ascends in the form of a series of gigantic steps. The rack is of the three-toothed type similar to that so familiar on the Swiss mountain railways. In winding through the gorge some of the most impressive vistas of Andine majesty are unfolded. There is the snow-capped crest of Aconcagua, beetling 23,500 feet to the sky, Tupungato 21,451 feet, Tolosa 19,000 feet, and many another white-hooded mountain giant. The Trans-andine ranks as one of the greatest scenic railways in the world, for it unlocked the door to what previously was regarded as one of the most inaccessible sight-seeing centres on this globe. Already its station at Inca has developed into a popular mountaineering rendezvous, whence the ambitious essay to scale the caps of the Cordilleras. Some idea of the stupendous character of the railway’s ascent in this region may be gathered from the fact that in the last 8 miles to Las Cuevas it rises no less than 1,414 feet, and at this latter station the track lies nearly 2 miles above the Atlantic. Las Cuevas is at the foot of the summit ridge which is pierced by the tunnel carrying the railway into Chile. This part of the work proved the most trying, for it involved wrestling with innumerable difficulties of great magnitude and peculiar character, such as are experienced very seldom in tunnelling operations. Though the range is not pierced at such an altitude as by the famous Galera tunnel in the country next door, yet it is three times as long. The engineers had to drill, blast and excavate their way through the rock of the ridge for 10,000 feet--nearly two miles--and at times the obstacles that loomed up suddenly proved extremely perplexing. The completion of this work delayed the opening of the railway considerably, for calculations and anticipations were upset rudely when excavation commenced.