Before them was a large and rapid river, its current impeded by a multitude of rocks and broken by rapids and cascades. They were destitute of ropes or tools suitable for boat-building, and any ordinary kind of boats would have been of no use to them in such a stream. It occurred to them that what they needed to navigate a river of this character was something of the nature of large baskets or tuns, in which they might float enclosed to their waists, while keeping themselves from contact with the rocks by the aid of poles. They had no models for such floating contrivances, and were obliged to invent them. Near the river was an extensive forest, and this supplied them abundantly with young trees, of light wood. These they cut down, stripped off their bark, collected them by fives, and, lacking ropes, fastened them together with lianas and a tenacious kind of gum which the forest provided. A large number of small, frail, basket-like contrivances were thus made, each large enough to carry two men, with whom they would sink in the water as deep as the waist. Piperies, Lussan called them, but his description does not make it clear just what they were like. While thus engaged, the freebooters killed part of their horses, and salted their flesh for food, all the work being done with the energy and activity necessary in their critical situation. During it they were not molested by the Spaniards, but no one could tell how soon they might be. When all was ready they restored their prisoners to the liberty of which they had long been deprived, and entered upon one of the most perilous examples of navigation that can well be imagined. Launched in their piperies, the freebooters found themselves tossed about by the impetuous current, and speedily covered with spray. The lightness of their floating baskets kept them from sinking, but the energetic efforts they were obliged to make to keep from being thrown out or dashed on the rocks soon exhausted them. A short experience taught them the necessity of fastening themselves in the piperies, so that their hands might be free to keep them from being hurled on the rocks. Occasionally their frail crafts were overturned or buried under the waves in the swift rapids, and the inmates were either drowned or escaped by abandoning the treasures which weighed them down. Whatever else may be said of this method of navigation, it proved a rapid one, the frail barks being hurried on at an impetuous speed. Each of the cataracts was preceded by a basin of still water, and here it became necessary to swim to the shore and descend the rocks to the bottom of the fall. Some who remained behind threw the piperies into the stream to be carried over the liquid precipice, and recovered by swimming out to meet them, or replaced by new ones when lost.