"Here is where we turn off," he said finally.
Jud suddenly produced two large, supple ox-hides which he had carried rolled up back of his saddle.
"So long as we're goin' treasure-huntin'," he remarked "an' Scar Dawson is still above ground, I calculate to tangle our trail before we start."
Under his direction, the whole party rode on for a mile farther, and then doubled back and turned off at right angles from the trail, Jud spreading rawhides for each mule to step on. Their progress was slow, but at the end of half a mile they were out of sight of the original trail and had left no tracks behind except hollows in the sand, which the wind through the day would cover and level.
For the next three days Professor Ditson guided them by the map among a tangle of wild mountains and through cañons so deep that they were dark at midday. At night their camp-fire showed at times like a beacon on the top of unvisited peaks, and again like a lantern in the depths of a well, as they camped at the bottom of some gorge. Here and there they came upon traces of an old trail half-effaced by the centuries which had passed since it had been used in the far-away days when the Incas and their followers would journey once a year to the sacred lake with their annual offerings. Even although Professor Ditson had been to Eldorado before, yet he found it necessary continually to refer to the map, so concealed and winding was the way.
On the third day they reached a wide plateau which ranged just above the tropical jungles of the eastern lowlands. At first they crossed bare, burned slopes of rock, with here and there patches of scanty vegetation; but as they came to the lower levels they found themselves in a forest of vast cacti which seemed to stretch away for an immeasurable distance. Some of the larger specimens towered like immense candelabras sixty and seventy feet high, and there were clumps of prickly-pears as big as barrels and covered with long, dark-red fruit which tasted like pomegranates. Underfoot were trailing varieties which hugged the earth and through which the mules had to pick their way warily because of the fierce spines with which they were covered. Some of the club-cacti were covered with downy, round, red fruit fully two inches in diameter, luscious, sweet and tasting much like huge strawberries. Jud, who firmly believed that eating was one of the most important duties and pleasures of life, nearly foundered before they reached the pampas beyond the thorny forest. There they had another adventure in South American foods. As they were crossing a stretch of level plain, suddenly a grotesque long-legged bird started up from the tangled grass and, with long bare neck stretched out horizontally and outspread wings, charged the little troop, hissing like a goose as he came.
"Don't shoot!" called out Professor Ditson to the startled Jud, who was the nearest one to the charging bird. "It's only a rhea, the South American ostrich. He'll run in a minute."
Sure enough, the old cock rhea, finding that he could not frighten away the intruders by his tactics, suddenly turned and shot away across the level plain, his powerful legs working like piston-rods and carrying him toward the horizon at a rate of speed that few horses could have equaled. In the deep grass they found the nest, a wide circular depression containing thirty great cream-colored eggs, the contents of each one being equal to about a dozen hen's eggs. The Professor explained that the female rheas of each flock take turns laying eggs in the nest, which, as a fair division of labor, the cock bird broods and guards. After incubation starts the shell turns a pale ashy gray. The party levied on the rhea's treasure-horde to the extent of a dozen glossy, thick-shelled eggs, and for two days thereafter they had them boiled, fried, roasted, and made into omlets, until Jud declared that he would be ashamed ever to look a rhea in the face again.
At last, about noon of the fifth day after leaving Yuca, the trail seemed to end in a great wall of rock high up among the mountains. When they reached the face of this cliff it appeared again, zigzagging up a great precipice, and so narrow that the party had to ride in single file. On one side of the path the mountain dropped off into a chasm so deep that the great trees which grew along its floor seemed as small as ferns. Finally the trail ended in a long, dark tunnel, larger and higher than the one through which they had passed on the way to Yuca. For nearly a hundred feet they rode through its echoing depths, and came out on the shore of an inky little lake not a quarter of a mile across, and so hidden in the very heart of the mountain that it was a mystery how any one had ever discovered it. Although it sloped off sharply from its bare white beach, Professor Ditson told them that it was only about twenty feet deep in the center. A cloud of steam drifting lazily from the opposite shore betokened the presence of a boiling spring, and the water, in spite of the latitude, was as warm as the sun-heated surface of the Amazon itself.
Leading the way, Professor Ditson showed them, hidden around a bend, a raft which he and his party had built on their earlier visit, from logs hauled up from the lower slopes with infinite pains. Apparently no one had visited the lost lake since he had been there, and a few minutes later the whole party were paddling their way to the center of Eldorado, where lay hidden the untold wealth of centuries of offerings.