PLATEAU OF CAXAMA11CA 277 



destroyed them ; and this still more towards the sea-coast, (for 

 the sake of obtaining fine cut stones for new buildings ; and 

 where the want of water consequent on the destruction of the 

 aqueducts has rendered the soil barren), than on the ridges of 

 the Andes, or in the deep-cleft valleys by which the mountain 

 chain is intersected. In the long day's journey from the 

 syenitic rocks of Zaulaca to the Valley of Sari Felipe (rich 

 in fossils, and situated at the foot of the icy Paramo de Ya- 

 moca), we were obliged to wade through the Rio de Guan- 

 cabamba (which flows into the Amazons), no lees than 

 twenty-seven times, on account of the windings of the 

 stream; while we continually saw near us, running in a 

 straight line along the side of a steep precipice, the remains 

 of the high built road of the Incas with its Tambos. 

 The mountain torrent, though only from 120 to 150 English 

 feet broad, was so strong and rapid that, in fording it, 

 our heavily laden mules were often in danger of being swept 

 away by the flood. They carried our manuscripts, our dried 

 plants, and all that we had been collecting for a year past. 

 Under such circumstances one watches from the other side 

 of the stream with very anxious suspense until the long 

 train of eighteen or twenty beasts of burden have passed in 

 safety. 



The same Eio de Guancabamba, in the lower part of its 

 course, where it has many falls and rapids, is made to serve 

 in a very singular manner for the conveyance of correspond- 

 ence with the coast of the Pacific. In order to expedite 

 more quickly the few letters from Truxillo which are in- 

 tended for the province of Jacn de Bracamoros, a " swimming 



