Still, the only certain thing about it is that if you go high enough you will pay the penalty; but no one can tell you how high that is, nor can you yourself learn finally, even by experiment. You may start out with a party from one of the inland towns of Peru, say at an elevation of 7,000 to 8,000 feet—and even there many are greatly affected by the altitude. One of the party, and perhaps the most robust looking, may become so dangerously sick at 10,000 feet that he will have to be sent back at once. The rest may go on safely to 12,000 feet, and there another succumb, and so on. And you may (though it is very unlikely) toil on even up to 17,000 or 18,000 feet without serious symptoms, and then a few days later be so terribly affected at 10,000 feet that only the most rapid removal to lower levels will save your life. Myself, I have never felt the mountain sickness. But then, my constitution is a most extraordinarily pig-headed one, which seems to butt against almost any wall with impunity. I have climbed and worked hard at considerably over 19,000 feet, and for a long time lived from 12,000 to 15,000 feet above the sea, and never felt anything worse than room for an extra pair of lungs, there where is really precious little air to breathe. But warning was all around, so that I never felt quite sure my turn would not come next.
There is much in habit, of course. You all remember the Irishman’s horse which learned to live on shavings—though unfortunately it died just as it was becoming accustomed to this economical diet. And lungs, too, can get used to living on such shavings as the upper air—that is, if there are lungs enough and you give them long enough. Many die in the learning, but in centuries a type is fixed. So with Andrés. His fathers for a thousand years had breathed no heavier air than that of the great Bolivian plateau. He had been born on one of the “little hills” beside Lake Titi-caca, and brought up there. Leadville is the highest considerable town in North America, and it is too elevated for a great many people; but Andrés had never in his life got so low as 11,000 feet. If he were suddenly set down in New York his lungs would be almost as much embarrassed as would yours if you were so suddenly snatched up to his skyward home. He might almost call for an ax to break that thick air up into breathing chunks! And you, sitting with bloodshot eyes and open mouth, would be wondering what skim-milk atmosphere was this, that in ten minutes’ gasping you could not get as fair a fill to your lungs as you now get with every breath you draw.
The mule was a well-seasoned mule, born in Puno and never any nearer sea level than that 12,500-foot town. True, it was now some 4,000 feet nearer the sky, and barely crawling up the pass. At every half-dozen or dozen paces it paused to groan despairingly, panting full five minutes before it could go another step. But that was a good mule. If you wished to see what an ordinary mule did in the pass, you had only to look at either side of the trail almost anywhere. There were hundreds of bleached skeletons lying just where they had fallen, but white as the snows upon the peaks above. Here and there were even the bones of the llama[27]—the highest-dwelling quadruped on earth. As for horses, their usefulness ceases long before reaching such altitudes as that of the Quimca-chata. I have seen people who had an air of feeling that the mule ought always to be begging pardon for being alive, and that nature was in pretty small business when she made him. But that, of course, is a notion of very uninformed folk. In fact, as all know who have stirred out a little, the mule is the most broadly useful animal in the service of man. The horse can run faster, the elephant carry heavier loads, the llama climb higher above the clouds; but no other beast can carry so much so far, so fast, so low and so high as this unpretentious and maligned big-ears; and wherever civilized man has had to conquer the wilderness this has been his best friend.
Something of this was in the thought of the traveler sprawled beside the apacheta at the head of the pass—watching now the gasping saddle-mule near him, and now the rest of his small caravan as it crept upward. He was breathing with open mouth, but otherwise showed no traces of the hour’s climb since he left Andrés and the pack-beast, and tramped on, driving his own mule ahead rather than ride the distressed beast.
“Yes,” he was saying (but to himself, which called for no expenditure of breath), “old Tom Moore, Crook’s chief packer, was right when he used to say, ‘God made mules a-purpose!’ How they have been the right hand of the pioneer in both Americas. Bien, Andrés—so you got him up at last.”
Andrés took off his frowsy hat, leaving upon his head the long-peaked knit cap of vicuña[28] wool, removed from his mouth the quid of coca leaves he had been chewing, and flung the wad against the rough, upright stone, which was already pimpled all over with similar offerings. No mountain Indian of Bolivia would any more think of passing such a monument at the crest of a pass without making this sacrifice than you would think of going into church with your hat on.
“Si, viracocha,” he answered, with a slow, good-natured smile; and went on in his stumbling mixture of Spanish and Aymará. “You ought to bite the coca, ps, viracocha, that the sorojchi catch you not. For so do we of the mountains, and by it we get our strength. Take”—and he drew from his left-hand pouch a pinch of the dried leaves and a bit of lime.
The American shook his head, with a smile, as much as to say: “Thanks, but I need it not.” Then he rose, with a significant glance at the clouds, and made a gesture of haste, pointing to the trail which from their feet dipped far downward to the east.