Crossing the Paso de Arricroo between the greatest cluster of peaks in the Andes, south of Quito, the railway reaches Vuicarrago, one hundred miles from Arequipa, the highest town in the world, where the barometer in the plaza shows an elevation of 14,443 feet. The ascent to it is usually made by stages, the traveller taking two or three days for it, so as to accustom himself gradually to the altitude; for the sudden change from tide-water to this enormous elevation--a distance of only two hundred and seven miles--generally brings on that distressing disease sirroche. It is always painful, and often dangerous. The first symptom is numbness of the limbs, then dizziness and nausea; the blood bursts from the ears and nose, the lips crack and bleed, a feeling of faintness makes it impossible to stand, and there is no cure but absolute quiet or a return to a lower altitude. During the construction of the railway a great many men died from the effects of the dreaded sirroche, which is often followed by a sudden and quickly fatal mountain fever. Few people escape the ailment, and no animal but the llama and others of that species native to the mountain regions can survive. At every town along the road droves of llamas can be seen which have been driven in from the mountain settlements laden with furs and skins, or with ore from the mines. The llama is the only beast of burden in the Upper Andes, and is docile, patient, sure-footed, and speedy. It can carry a burden of one hundred pounds, which is fastened to a pack-saddle, and when that weight is exceeded will lie down and refuse to move until the surplus is removed. The llama is about as large as a one-year-old colt or a good-sized black-tail buck. It has a heavy coat of wool; but those that are used for transportation purposes are seldom sheared. The vicuña, a sort of gazelle, a gentle, timid animal, is found in large numbers in the interior of the Andes, particularly in Bolivia. It is fawn-colored, has long, soft, silken hair, with a peculiar gloss that resembles what are known as “changeable [Illustration: THE VICUÑA.] silks,” and changes color in different lights. In the old Inca days, before the Spanish invasion, centuries ago, the vicuña was the royal ermine of the Inca kings, and no one but the Imperial family and nobles of a certain rank was allowed to wear it. The animal was also protected by some sacred tradition, and was allowed to go unharmed in the forests, where it accumulated in great numbers; but the Spanish invaders, regardless of all rights, human and divine, hunted it down, and slaughtered it for food. The Indians expected that some severe penalty would be visited upon the invaders for destroying and eating the sacred animal, and lost faith when they escaped divine retribution. Now vicuña skins are very scarce and are expensive, and the natives attempt to [Illustration: LAKE TITICACA.]