CHAP. XXV. OF THE TWENTY YEARS. 



eighty million seven hundred and thirty-six thou- 

 sand, being added, will make together one hundred 

 and three million seven hundred and thirty-six 

 thousand pounds ; but as the mines of Russia in 

 the early part of the period were less productive 

 than towards the end of it, we may make an allow- 

 ance of the three millions seven hundred and 

 thirty-six thousand pounds for that circumstance, 

 and take the whole amount as one hundred mil- 

 lions, or five millions annually. 







that found in the lead in some of the northern mines. It is 

 said to have amounted to as much as one hundred and eighty 

 thousand pounds in value. On the whole term here considered, 

 the amount here is but small, and it affects the calculation of 

 Humboldt in too slight a degree to make any alteration neces- 

 sary in the estimate he has formed. 



