114 
Some Account of the Lead Mines of Ajmir. [April, 
These excavations are from 10 to 12 feet square, and 3 or 4 deep, and having been 
filled with water, the work of the ore-washers commences. Each man has a 
wooden tub, its shape being the frustrum of a cone ; altitude 18 inches ; diameter 
of the top 3 feet, and bottom 1 foot. Having placed themselves on the verge of the 
pit, and on a level with the water, and a portion of the pulverized ore being 
thrown into the tub with some water, they are able, from its shape, to keep the 
tub floating, while the contents are violently stirred up with the hands. After 
having been well mixed, the ore is allowed to subside, by gradually drawing the 
tub backwards and forwards on the surface ; and as the metallic particles, from their 
gravity, quickly sink to the bottom, the sand and other impurities are easily skimmed 
off by the hand. This operation is repeated 20 or 30 times, until the ore be com- 
pletely cleansed. The sediment collected in the pits is, from time to time, removed, 
and the water renewed once a week, or oftener, when the evaporation is consi- 
derable. 
3. The washing having been completed, the ore is then delivered over to a 
separate set of people, who, having intimately mixed it with its weight ot fresh 
cowdung, roll it into small balls, about the size of a pigeon's egg, and allow it to 
remain exposed to the influence of the sun, until it becomes perfectly dry, when 
it is ready for smelting. 
4. The process of smelting is marked by the same simplicity that characterizes 
the previous operations. The furnace is nearly cylindrical ; upper diameter 11 
inches, lower 10 inches ; altitude 3 feet. Three clay pipes are luted to the circum- 
ference, and serve to communicate the blast from a& many bellows ; while from 
their rather angular shape, a hole is left for clearing the end of the pipe, or stirring 
up the ignited ore, at the same time that these orifices allow the workmen to 
observe the state of fusion. Each bellows consists of a half dressed goat skin; the 
smaller end being tied to the pipe. The mouth of the skin held in the hands, is 
compressed by a man bearing his Weight perpendicularly on it. They are worked 
simultaneously, and the blast is so disposed as to fall in the centre of the base, 
The aperture for the escape of the scoria, is 5 inches higher than the taps or metal 
hole on the opposite side. Two advantages attend the mixture of cowdung with 
the ore. A cheap fuel is furnished, and from its wide dispersion in this medium) 
added to the sphericity of the balls, the minutest particles are exposed to the action 
of the fire, and a most complete fusion is effected. By the use of cowdung, the 
expenditure of charcoal, the only fuel, is very inconsiderable. Half to three 
quarters of a mound is amply sufficient for one mound of fused metal. After it has 
been lighted, the furnace is, from time to time, alternatively fed with balls and 
charcoal. In about 3 or 4 hours the ore has become perfectly liquid, when the 
scoria hole is opened to allow of its passage. The metal is then drawn off, and 
run into moulds. The subsequent tappings take place about every hour and a half) 
4 or 5 being the general number. The quantity of metal smelted in one day, (ot 
about 9 hours,) from this small furnace, averages from 2 to 3 cwt. The worst 
one yields about 31 per cent, of metal ; the general run 40 : while the best gives from 
50 to 58 per cent. 
On reviewing the process in all its stages, the question naturally arises, co»« 
not improvement be advantageously introduced ; or do the operatives, in the* 
present rude way, make the most of the work ? The introduction of machinery, 
by decreasing manual labour, naturally tends to a diminution of expense*; »« d 
were localities to favour its adoption, and the demand to be commensurate with 
dient- 
!!*? '“'ll ° Pe ? ti0n f W !' iCh , ' V ° Uld thus be “tended, its use would he expec 
n Th- " 1< ' rr "' ’ that loc »l circumstances are unfavourable to the nieasW'' 
Tins Will much depend upon the price of labour, as well as the kind of «r°*' EP ’ 
