"I was thinking the same thing," said Frank, "and we shall save more than the cost of the building when we make our bargain with the alcalde for boats, to go down the river." [Illustration: NEAR THE VILLAGE.] It was the first new house erected in that village for several years, and the alcalde was covetous. The prediction of the youths was correct, and the old fellow was quite active in speeding the parting guests. When the Indians returned from their turtle-hunt the bargains were easily made and the necessary boats and men obtained. But they did not return for a week, and while we are waiting for them we will take a glance at the Beni and observe its peculiarities. The Beni is formed by several head streams, that rise in the Andes east and northeast of the plain of Titicaca. It flows to the northwest for about three hundred miles, receiving numerous tributaries, and then in a northeasterly direction to the frontier of Brazil. Here it enters the Madeira, which is formed by the Mamoré and Iténez Rivers, and from the point of junction its name and identity are lost. It is the largest of the affluents of the Madeira, and is thought to be equal to both the other streams combined. It is half a mile wide at its mouth, and fifty feet deep, and is estimated to discharge at an ordinary stage five thousand cubic yards of water every second. The Beni and its tributaries are navigable for many hundreds of miles in the interior of Bolivia; how far this navigation may be carried is not known, as no complete survey has been made. With a fleet of steamboats on the Beni and its kindred streams, and a railway around the falls of the Madeira, the resources of Bolivia could be developed with ease; until that work is accomplished the foreign commerce of the country can never be extensive. Through much of its course the Beni runs through forests, but there is also a wide extent of pampas or grassy plains, where millions of cattle and horses might find pasturage. So abundant and cheap are the cattle at the present time that they are killed for their hides alone, the flesh being left to rot on the ground. The other rivers that form the Madeira traverse a similar country, but have their sources farther east than those of the Beni. They are fed by the rains brought from the Atlantic by the easterly winds, which are heavily charged with moisture. Frank and Fred were not slow to win the confidence of the Indians during their stay at the village; through the aid of Manuel, who understood the language of this people, they learned some of the ways of native life on the tributaries of the Amazon. They did not hesitate to ask questions about anything they saw; sometimes the answers were evasive, while at others the information sought was readily obtained. While visiting one of the huts Fred espied some reeds, ten or twelve feet long and perfectly straight, among the rafters of the building. Pointing to them, the youth asked what they were for.