70 mallet: geology of darjiling and western duars. 



After a preliminary breaking-up of the larger pieces and rejection of the 

 refuse, the picked ore is broken up small on flat stones, with hammers 

 formed of suitably-shaped pieces of quartzite, or other hard rock, tied 

 into forked sticks. Subsequently it is pounded to a coarse powder with 

 heavier hammers of the same kind. 



The powder is washed in troughs made of rough planks fixed on 

 the ground, one forming the bottom, which has a slight incline, and the 

 others fixed on edge. In form and size the troughs resemble small 

 coffins, but the top and lower end are open. A small stream of water 

 flows though, which is regulated in quantity by a dam of clay at the 

 upper end. A hollow is made in the dam to allow a sufficient stream to 

 flow into the trough, while the surplus water runs off by another channel. 

 The ore is continually agitated by hand, or with a small basket-work 

 shovel, and moved towards the upper end of the trough, by which means 

 the larger fragments of copper pyrites, and of mundic if the ore be con- 

 taminated with it, are collected there, and the lighter residue carried 

 lower down. This residue, which still contains some ore, is ground in 

 hand-mills similar to those used in India for grinding corn, with grinding 

 surfaces formed of slabs of gneiss. It is then re-washed in the same 

 way as before, and the same operations sometimes repeated on the 

 residue. The ore from the different washings is mixed together, aud 

 is ready for smelting. Most of the dressing operations are done by 

 women. 



The smeltiug-furnace is generally built with some neatness, of 



refractory clay; but in its ruder form consists 

 Smelting. 



merely of a hole dug in the ground, with a low 



clay rim along the sides and front, and a higher one, or a flat stone, at 



the back ; the inside is plastered with refractory clay if that of the 



ground itself be not sufficiently infusible. The furnace is about 18 



inches deep, a foot square at the top, and tapering a good deal towards 



the bottom. When it is dry, small charcoal is filled in* to a depth of 



about a foot, and beaten down by a wooden rammer till a saucer-shaped 



( 70 ) 



