All day the pauper's-coffin-_cum_-orange-box was kept hard at it. Even during the terrific midday heat, with nothing save their broad-brimmed straw hats to shield them from the almost vertical rays, they stuck it gamely. Their freak craft was taking them steadily at four knots "over the ground", in spite of an adverse current which they encountered as soon as the influence of the tide ceased. Well before nightfall, the boat was alone on the river. Rarely were craft of any description to be encountered fifty miles above Tepecicoa. Occasionally, an Indian canoe, rough-hewn from a tree-trunk, was seen keeping discreetly close to the well-wooded banks, but civilized Rioguay seemed to have halted sharply at a spot where a range of low hills dipped to allow the now shallow stream to pass on its way to the ocean. So far, the craft that had aroused Peter's resentment had done remarkably well. He was beginning to feel a certain amount of confidence in her; but, he reminded himself, there had been no wind and the water was as smooth as a mill pond. As a matter of fact, a tornado might be blowing and the surface of the river would be hardly ruffled, provided the wind was at right angles to the course of the stream, for the banks were high and deeply wooded. In places the giant vegetation almost formed a complete archway over the river. Caymans floated idly on the water, looking more like half-sunken logs, until the approach of the motor-driven boat aroused them from their lethargy. Enormous eels, some of them of the deadly electric variety, could be seen beneath the placid surface, giving promise of a horrible death to any human being who, by accident or design, had to take to swimming in those cool and tranquil waters. Through the foliage came the unmistakable signs of the presence of jaguars and panthers, while more than once Peter caught sight of an enormous anaconda gliding over the branches. With death lurking in the water and in the forests on either side, the prospect did not seem particularly alluring. Well before sunset, the boat was run ashore on a small island, almost destitute of trees and covered with high grass. On one side there was a narrow sandy beach. The other sides were composed of rock rising sheer out of the water to a height of about ten feet. "This looks like a comfortable camping-ground," observed Uncle Brian, as he leapt ashore and stretched his cramped legs. "According to the map, we're only five miles below the junction of the Rio Tinto and the Rio Guaya. I'd like to push on and get clear of the forests for a while, but it's too risky in the dark." "S'pose it's all right," responded his nephew, "but how about the grass? I've no particular desire to get chawed up by a jaguar or pipped by a snake. And if we sleep on the sand, or even in the boat, there's a chance of a hungry alligator butting in."