. 
62 Sketch of the Mine of Pasco. 
ter of the mines, by means of the sulphuric acid and sulphates it con- 
tains in solution, destroys the body of the iron pumps and the cal- 
dron ; it has been observed that those of the copper are not so. easily 
attacked, and it would be more convenient for the future, if other ma- 
chines were used, to have the pieces which come in contact with the 
acid, of the same metal. The iron mines are situated about Yauri- 
choca, St. Rosa, Caya, Yanacancha, and Matajente, extending a 
league in length, and a quarter in breadth. About five hundred and 
fifty eight mines are found here, and all are more or less productive. 
{n Caya, are many rich mines belonging to Vivas and others 3 in Yan- 
achanea, are found those of Rosarios, Aninus, Jesus Nazarene, San 
Judas, &c. belonging to the miners Vivas and Maturna. _ It is affirm- 
ed, and not without foundation either, notwithstanding the short time 
e machine was at work there, that this place is richer than all the 
others put together, but now there is not a particle of metal extract- 
ed, because it must be worked under water. Matajente was once 
the richest point of the chain, and the excavation as well as many 
other points exposed to view, confirms it. It was ruined by an ac- 
cident, by which three hundred workmen were buried. If the ex- 
cavation of Yanachanca, as well as that of Avellafuerte, were brought 
to this point, very rich returns of metals would. be obtained, which 
would repay all labor and expense. All the mines of Yaricoche are 
very badly wrought; no art or economy is observed in the caverns; 
the lives of the men are exposed, the moment they set their feet on 
the threshold of an aperture in one of these mines ; the method they 
have observed and still pursue, is to open upon an eastern exposure, 
some air holes of various dimensions, all inclined according to cir- 
cumstances. ‘Then they pursue the. stratum, making tubes of the 
space ; in others they make spacious arches, without leaving buttresses 
or bridges, as in the mine of St. Catalina and Trinidad. 'The system 
of galleries in a series, and the communication from one to another by 
the circulation of the air, and facility of the transportation of the min- 
erals is not carried on in perfection, and they only make wells with 
the same irregularity which they practice in making the air holes. 
They set the laborers to work without any distinction, not pursuing 
the more easy and economical method practised in Huaypacha, and 
in the mine of Victorias, in the department of Puno. The air holes 
are so badly made, that there are dangerous intervals for want of 
steps to place the foot, and also for being ill secured by planks. As 
wood is very dear, they make continual use of the limestone 
