CHAP. X. MIDDLE AGES. 



potentates. Whatever it might have produced 

 under the Arabs must have been much less 

 than that subsequently extracted. Under the 

 Castilian monarchs many shafts were sunk and 

 several galleries constructed, and this swelled 

 the quantity of the treasure which was acquired. 

 Very extravagant accounts are given of the 

 amount obtained, but none of sufficient accuracy 

 to obtain credit except that of one author, the 

 historian of the house of Herasti, who says that 

 during a course of years (how many does not 

 appear) the mine yielded eight millions of pese- 

 tas a coin the fifth part of a hard dollar, or about 

 ten-pence of our money or about three hundred 

 and thirty thousand pounds sterling. This sum 

 is said by the same author to have been applied 

 to the building of that most enormous and 

 gloomy pile the Escurial. 



It is probable that at the most prosperous 

 period of their working, both those mines, but 

 especially that of silver, were attended with a 

 heavy loss to the crown ; and were consequently, 

 if not abandoned altogether, suffered to proceed 

 towards dilapidation ; and thus being a burden 

 to the possessor, were readily conceded to ad- 

 venturers on what were deemed advantageous 

 terms. 



Though the process of these mines from bad 

 to worse till they became extinct does not fall 

 within the period we are now considering, yet 



T 2 



