few places could observations be made on the topography of distant ranges. Paced distances of a half mile at irregular intervals were used for the estimation of longer distances. Directions were taken by compass corrected for magnetic deviation as determined on the seventy-third meridian (See Appendix A). The position of Rosalina on Robledo’s map was taken as a base." tag="{http://www.w3.org/1999/xhtml}img"/>

Fig. 8—Sketch map showing the route of the Yale-Peruvian Expedition of 1911 down the Urubamba Valley, together with the area of the main map and the changes in the delineation of the bend of the Urubamba resulting from the surveys of the Expedition. Based on the “Mapa que comprende las ultimas exploraciones y estudios verificados desde 1900 hasta 1906,” 1:1,000,000, Bol. Soc. Geogr. Lima, Vol. 25, No. 3, 1909. For details of the trail from Rosalina to Pongo de Mainique see “Plano de las Secciones y Afluentes del Rio Urubamba: 1902-1904,” scale 1:150,000 by Luis M. Robledo in Bol. Soc. Geogr. Lima, Vol. 25, No. 4, 1909. Only the lower slopes of the long mountain spurs can be seen from the river; hence only in a few places could observations be made on the topography of distant ranges. Paced distances of a half mile at irregular intervals were used for the estimation of longer distances. Directions were taken by compass corrected for magnetic deviation as determined on the seventy-third meridian (See Appendix A). The position of Rosalina on Robledo’s map was taken as a base.

We could gather almost no information as to the nature of the river except from the report of Major Kerbey, an American, who, in 1897, descended the last twenty miles of the one hundred we proposed to navigate. He pronounced the journey more hazardous than Major Powell’s famous descent of the Grand Canyon in 1867—an obvious exaggeration. He lost his canoe in a treacherous rapid, was deserted by his Indian guides, and only after a painful march through an all but impassable jungle was he finally able to escape on an abandoned raft. Less than a dozen have ventured down since Major Kerbey’s day. A Peruvian mining engineer descended the river a few years ago, and four Italian traders a year later floated down in rafts and canoes, losing almost all of their cargo. For nearly two months they were marooned upon a sand-bar waiting for the river to subside. At last they succeeded in reaching Mulanquiato, an Indian settlement and plantation owned by Pereira, near the entrance to the last canyon. Their attempted passage of the worst stretch of rapids resulted in the loss of all their rubber cargo, the work of a year. Among the half dozen others who have made the journey—Indians and slave traders from down-river rubber posts—there is no record of a single descent without the loss of at least one canoe.

To reach the head of canoe navigation we made a two weeks’ muleback journey north of Cuzco through the steep-walled granite Canyon of Torontoy, and to the sugar and cacao plantations of the middle Urubamba, or Santa Ana Valley, where we outfitted. At Echarati, thirty miles farther on, where the heat becomes more intense and the first patches of real tropical forest begin, we were obliged to exchange our beasts for ten fresh animals accustomed to forest work and its privations. Three days later we pitched our tent on the river bank at Rosalina, the last outpost of the valley settlements. As we dropped down the steep mountain slope before striking the river flood plain, we passed two half-naked Machiganga Indians perched on the limbs of a tree beside the trail, our first sight of members of a tribe whose territory we had now entered. Later in the day they crossed the river in a dugout, landed on the sand-bar above us, and gathered brush for the nightly fire, around which they lie wrapped in a single shirt woven from the fiber of the wild cotton.