INTRODUCTION. 



panies, had undoubtedly opportunities of 

 making important observations, and from 

 them valuable data will probably be ob- 

 tained. 



I myself had the sole management of one 

 of these Companies ; but, from particular 

 circumstances, it will be proper to show that, 

 excepting for my Reports, I had little time 

 or opportunity to make any memoranda be- 

 yond those of the most trifling description 

 of personal narrative. 



I was on duty at Edinburgh, in the corps 

 of Engineers, when it was proposed to me 

 to take charge of an Association, the object 

 of which was to work the Gold and Silver 

 Mines of the Provinces of Rio de la Plata ; 

 and, accordingly, at a very few days' notice, 

 I sailed from Falmouth, and landed at Bue- 

 nos Aires about a week after the Cornish 

 Miners had arrived there. 



