"You have just eaten your supper, Señor Lieutenante, and cannot judge; to-morrow I will give you some of these to try for yourself." During the next morning, after a wearisome climb, Filipe fulfilled his promise; he rolled a few particles of lime in two or three of the leaves, and, pressing the whole into globular form, handed it to Smyth. "Chew that," he said. "It is _coca_, and will sustain you for nearly an hour." Smyth had previously noticed both men stuffing something into their mouths periodically, but, being so used to seeing the sailors chew tobacco, he had never given it a second thought. He chewed lustily at the little ball for five minutes, but succeeded in extracting neither taste nor nourishment from it. "I think I should prefer salt pork," he said. "What little taste your coca has is beastly; and I am as hungry as I was before." "Patience; you have not chewed it long enough." He tried again, and presently the Indian said with a smile: "Well, Señor?" "I don't know how it is, but I'm losing my hunger. _You_ try it, Frank.--Give my friend one." The Jevero shook his head doubtfully. "It must be a little one, then. It is not good for him. You smoke cigars, and you give some to us; but you do not give him one. With _coca_ it is the same." Smyth continued to chew, and was no longer conscious either of hunger or fatigue--for half an hour or more, when both these mortal ills began to return; and of course with double acuteness. He remarked on this to the Indians. "Ah!" said Luis; "now you know how we can tell the time without a watch, how we know the number of miles we have walked without counting our steps. When you feel to want new coca-leaves, thirty-five minutes have gone by; add the ten minutes during which you found no effect from them, and you observe that three-quarters of an hour has expired. In that time we walk, at the present rate, five miles." He might have added that, if abused, the coca habit is as pernicious and as degrading as opium-taking. "It will be five miles no longer now," said Filipe, interrupting. "Quick; blind the mules, Luis!" They immediately began to bustle about like seamen in a gale of wind, and, in a few minutes, each of the five mules had a cloth tied over his eyes. There was soon no need to ask why. The slope they had been ascending had become a level strip--literally a strip. To the left of them the sailors saw a sheer wall of rock, rising perhaps a hundred feet, while to the right, not more than eight feet from it, was the edge of a precipice. Used as they both were to overcoming inclinations to giddiness or fear, they shuddered involuntarily as they cast their eyes over the brink and found that they could see no bottom to the abyss. Yet the Jeveros put themselves on the mules' outer side, one leading a string of three, the other two, and walking heedlessly within a couple of feet of the precipice.