The canoes were to take them to the point where the river they were descending unites with the Beni; it was estimated that the downward journey would occupy two days, while the Indians would be eight or ten days in returning. In descending they keep the canoes in the middle of the stream, and take advantage of the current, but in ascending they hug the banks, and propel the boat by means of poles, or by dragging it around the rapids. The current is swift, as there is a considerable fall to the river; nowhere was the flow less than three miles an hour, and in many places it amounted to five miles. Several rapids were passed which had a dangerous appearance, and undoubtedly they would have been full of peril to any one unaccustomed to them. Dr. Bronson certainly looked very serious while passing the first of the rapids, and the face of Frank wore an expression of anxiety. But their possible doubt as to the result was removed when they saw the skill with which the popero swung his long paddle, dexterously brought the canoe around when it seemed about to go headlong on a rock, and let it glide past a whirling eddy which threatened to swamp it. They were only a few minutes in the rapid, but it seemed at least an hour to the travellers. [Illustration: A LANDING-PLACE.] The trees on the banks of the river showed that they were in the tropics. Palms of several varieties were visible, bamboos grew luxuriantly, banana bushes were numerous, while papayas, plantains, and similar vegetable growths were everywhere to be seen. Frank had his rifle ready for use in case of large game, but none was discovered; birds rich in plumage flew among the trees, but, like most of the birds of the tropics, they were seen rather than heard. Few tropical birds have the power of song, and it is possible that their brilliant feathers are given in compensation for their deprivation. But do not understand that all the birds of South America are unmusical. On the borders of Guiana is a rare bird, known as the Uruponga or Campanero, which may be rendered into English as "the tolling-bell bird." It is white, and somewhat smaller than a dove, and has a black tubercle under the beak. One traveller, Waterton, says of this bird, "Orpheus himself would drop his lute to listen to him, so sweet, so novel, and romantic is the toll of the pretty, snow-white campanero." Sydney Smith, in reviewing Waterton's narrative, says "The campanero may be heard three miles! This single little bird being more powerful than the belfry of a cathedral ringing for a new dean! It is impossible to contradict a gentleman who has been in the forests of Cayenne, but we are determined, as soon as a campanero is brought to England, to make him toll in a public place, and have the distance measured."