In one instance, we met with an exciting adventure. As we were crossing a broken range of mountains, we perceived a small animal, resembling a deer, pursued by a bird of enormous size. My guide immediately informed me that the quadruped was a vicuna, and that the pursuer was a species of vulture, which is familiar to most readers under the name of condor. When we first saw them, the vicuna was straining every nerve to escape, while the condor hung over his back, and at every opportunity struck his talons into his flesh. They both swept by us, so close that we could distinctly see every feature of the pursuer and pursued. The little quadruped was foaming at the mouth; his eye was wild and glaring, and his sides streaming with blood. The vulture, with his merciless gaze fixed upon his prey, held his talons ready for the blow, while he seemed to glance through the air on his outspread wings, like an arrow from the bow. On they went, till at last the vicuna came to a precipice of nearly two hundred feet in depth. Pressed by his remorseless enemy, he hesitated not for a moment, but taking the fatal leap, fell crushed and lifeless into the depths of the rocky gorge beneath. The condor wheeled round and round, and finally stooped with an easy motion to partake of his feast. I had some curiosity to see the monster at his meal. After winding round for a considerable distance, we reached the bottom of the ravine. We approached the savage bird, and perceived that he had already commenced his feast; he had torn open the bowels of the vicuna, and seemed to cut and rend the flesh with his enormous beak as easily as if it had been a butcher’s knife. As we drew near, he glared upon us fiercely, and seemed to deliberate for a moment whether he should not repel the unwelcome intrusion. Finding us not disposed to retreat, he seized his prey in his claws, and beating his wings with a furious impulse rose heavily upon the air. Bending his course slightly downward along the distant slope of the mountains, he continued for some time in view, and at last disappeared amid the mazes of the forest. Pursuing our way with diligence, we now began to ascend the mountains which encircled the valley of Potosi. Winding our way through deep vales, and often climbing along the dizzy edges of beetling cliffs, we reached the top of the mountain range and looked down upon the scene below. The wild and rugged ramparts which encircle this famous city, bear a desolate and wintry aspect. Scarcely a tree crowns their summits, and nothing but mosses and lichens seem to flourish in the chill and ungenial climate. Yet below, we could perceive bright patches of vegetation, seeming to indicate a milder temperature. Beginning now to descend, we proceeded with caution, and were soon lodged in the celebrated city of Potosi. [Illustration: _City of Potosi._] CHAPTER XV.