"I got down and walked over the bridge, partly through Federico's advice, but largely from my own inclination. I was uncertain what the mule might take into his head to accomplish during the transit, and did not regard it a good place for experiments. But the mules really behaved admirably; nothing could exceed their docility, and the most antiquated cart-horse was never more demure than they. A mule knows pretty well when and where to indulge in hilarity; he realizes that a swaying bridge a hundred feet above a mountain torrent is not to be used as a quadrupedal dancing-hall. "Turning a bend of the road beyond this bridge, we saw, far up a gorge, a stream that came out of a cavern, like an enormous spring. This is the one mentioned by Lieutenant Strain as having its source in the 'Lago Encantada,' or Enchanted Lake, more than a mile away. It was a mystery for a long time to the Indians, and a puzzle to several scientific visitors, what became of the water that flowed into the lake, as it had no apparent outlet. There was evidently a complete closing of the gorge which formerly drained the lake, by the fall of a vast mass of earth and rock, through the action of an earthquake; the water forced a subterranean passage and the mystery was explained. The Indians regard with awe everything they do not understand, and therefore concluded that the removal of the water was due to supernatural agencies. [Illustration: BY THE ROADSIDE.] "We soon entered a cultivated region, where the warm air was a pleasant relief to the chilliness of the upper elevations of the mountains. The descents were rapid, but no longer perilous, the bridges more substantial, and the roads wider. Grass and trees abounded; farms and farm-houses dotted the country; signs of population were everywhere evident; and the perils of our travels among the snow were things of the past. The houses grew into villages, and finally, just at sunset of the fifth day of our journey, we drew up in front of the posada at Santa Rosa and made our last descent from the patient and weary mules. "Santa Rosa is a long and rather straggling town with about five thousand inhabitants; like most Spanish-American towns, it has a large plaza, where the principal business is centred. A noticeable feature of the place is the stream of pure water, from the mountains, flowing in nearly every street; it comes from the melting snows of the Andes, and the supply is unfailing. The plaza was thronged with people when we arrived, and some of them looked curiously at the stranger within the gates. There was not the least sign of rudeness, but, on the contrary, an air of politeness which one does not always find in such an out-of-the-way spot as this. [Illustration: COURT-YARD OF THE POSADA.]