THE RAPIDS AND CANYONS OF THE URUBAMBA 



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 " Piano 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. Direc- 

 tions 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. 



