9G mallet: geology of darjiling and western duars. 



sledge. When so reduced that the whole would pass through what we temi " a three- 

 hole," or a sieve having nine holes in a square inch, they carry it to a strake, or 

 small incline, made with planks about 8 feet long 1| feet wide, having two sides and 

 head-boards ; and then wash off a great part of the impurities, which constitutes their 

 dressing department. The produce they make of the copper ore is about 10 per cent. 

 They then take the cleaned ore and put it with charcoal into a furnace, and two men 

 keep up a continual blast until the whole is melted to a regal or lump. 



Zndly— They bruise down the lump and mix it with cow-dung, then put it in a 

 slow fire for two days ; and for refining they again put it in the furnace with more 

 cow-dung and charcoal, and give it a strong heat until the whole is smelted or converted 

 to a fluid, the copper, being the heaviest, settles to the bottom. They work the pure 

 copper into cooking utensils, which they sell at about one rupee per seer. 



7. Their mining operations from the first to the last stands open to great improve- 

 ment, instead of working in the side of the hill as they now are, with the disad- 

 vantage of the lode underlaying in the hill, and, if I may be allowed the term, 

 pulling the ore out "by the hair of the head." 



I should recommend a level to be driven from or near the river on the course 

 of the lode, which would not only gain a good back or top, but prove to a fair depth 

 the intrinsic worth of the lode. Generally speaking, the copper lodes are found the 

 most productive, from 30 to 70 fathoms below the surface; and, as it cannot be 

 expected that one yellow copper ore lode of 2 or 3 feet wide can yield ore enough to 

 compensate any adventure for the outlay required in India, in fact such instances are 

 rare in England. Therefore I should recommend levels to be driven to intersect other 

 lodes ; points for driving could with little difficulty be marked out with bearings 

 during the dry season. As to the machinery required, it would depend greatly on the 

 condition the ore would be found in, also whether above or below the adit level; 

 but at all seasons of the year there is ample water power to work all machinery re- 

 quired. A crushing mill from 20 to 24 in diameter would be absolutely necessary. If 

 coals can be procured for smelting purposes, charcoal would be of but little moment. 

 I suppose with coals it would take fifteen parts to produce one part metal, allowing 

 the ore to produce 15 per cent. Then I should judge from the copper produced and 

 indications of the lode opened, as well as from the general appearance of the neigh- 

 bouring hills, that such explorations would in time prove the district to be a dividend- 

 paying mining locality. 



( 96 ) 



