CHAP. xxi. AMERICAN MINES. 125 



and looking at the extensive frontier which was to 

 be guarded. This would make the supply amount 

 to twelve million six hundred thousand piastres. 



Brasil at that time had begun to collect gold, 

 though not to the extent which it reached 

 in the following century ; it may, however, be 

 safely estimated, even then, at one million dollars. 

 To the supplies from America may be added what 

 little the mines of Europe and the rivers of Africa 

 contributed to the general stock, which appears 

 to have amounted to about one million four or 

 five hundred thousand dollars. Thus the sum of 

 fifteen million dollars annually, or taking the dol- 

 lars at four shillings and two-pence sterling, three 

 million three hundred and seventy-five thousand 

 pounds, would nearly agree with the estimate 

 which Humboldt has assumed. 



This would give an increase to the precious 

 metals in the whole century of three hundred and 

 thirty-seven million five hundred thousand pounds. 

 In the eighteenth chapter of this inquiry (page 

 70) the conclusion has been arrived at that the 

 stock in Europe applied to the purposes of money 

 might amount to about one hundred and thirty 

 millions sterling. If the same allowance be made 

 for wear in the hundred years as has been before 

 presumed, that coin which was in circulation at 

 the end of the year 1599 would in the year 1699 

 be reduced to eighty-seven million pounds. 



In the former period it has been estimated that 



