﻿I860.] 



F0KBES BOLIVIA AND PE1U7. 



21 



flushed off, and, being so much heavier than the rest, deposits itself 

 at but a little distance from the workings, where it is collected and 

 subjected to repeated washing in a trough until nothing but the 

 gold-dust remains behind. 



Eig. 1. — Sketch of the Gold-washings on the liiuer Chuquiaguillo. 



This excavation is deepened until the lowest available auriferous 

 stratum has been reached, and then abandoned, in order to carry on 

 the same operation parallel to it ; the boulders and stones met with 

 in the new working are thrown into the old excavation, and such 

 excavations are continued right across the valley. In a valley of 

 considerable breadth it would be impossible, except by emploj-ing an 

 immense number of hands, to open out and lay bare the whole of the 

 auriferous ground in one excavation. 



The auriferous strata occurring in these diluvial accumulations 

 are, in Bolivia, generally known by the name of " Veneros," and ap- 

 pear to correspond to what are technically termed " floors " by the 

 gold-diggers of California and Australia, being, as it were, the floor 

 or clay-bottom upon which the gold-dust had settled down, subse- 

 quently covered up by alternating beds of coarser sand, gravel, and 

 boulders : above this a similar floor and coarser beds might in their 

 turn be found, as in the sketch of the washings on the Chuquia- 

 guillo (fig. 1) : and where these diluvial strata are of still greater 

 thickness, a proportionate number of " veneros " are generally found 

 to occur. 



These " diggings " are, as might be expected, confined to the sides 

 of valleys and beds of rivers which contain water* sufficient for 

 washing. The celebrated workings of Tipuani and those in the 



* The rivers of this part of the world arc too frequently " Rios Secos," a 

 Spanish term which is generally adopted. 



