260 
the perforated nostrils of which were moveable 
rings of the same stone When I crossed the 
Cordilleras by the Paramo of Assuay, and saw 
the enormous masses of stone extracted from the 
porphyry quarries of Pullal, employed in con- 
structing the high roads of the Inca, I already 
began to doubt, whether the Peruvians were not 
acquainted with other tools beside hatchets of 
flint ; I suspected, that grinding was hot the 
only method they had employed to smooth the 
stones, or give them a regular and uniform con- 
vexity ; and I then adopted an opinion contrary 
to the ideas generally received ; I conjectured, 
that the Peruvians had tools of copper, which 
mixed with a certain proportion of tin acquires 
considerable hardness. This conjecture has 
been justified by the discovery of an ancient 
Peruvian chisel, found at Vilcabamba, near 
Cuzco, in a silver mine worked in the time of 
the Incas. This valuable instrument, for which 
I am indebted to the friendship of P. Narcissus 
Gilbar, and which I have brought to Europe, is 
twelve centimetres long and two broad. The 
metal of which it is composed has been analyzed 
by Mr. Vanquelin, who found in it 0*94 of cop- 
per, and 0*06 of tin. This keen copper of the 
Peruvians is almost identical with that of the 
* Memoires de I’Academie de Berlin, 1746, p. 452, lib. 7, 
f. 4. 
