OF CORNWALL. 203 
As to the mining part, copper- works do not differ from thole of sect, xi, 
tin materially, but the method of dreffmg or preparing the metal fifing, 
for fale is very different. To feparate the good ore from the bad dreffilfg the* 
with greater advantage, certain overfeers e are appointed to fuper intend copper cre ‘ 
the labouring miners, and fee that all the richer forts of ores be kept 
together in the bottom, then raifed as unmixed as may be, and laid 
forth on the grafs in diftinct heaps ; and becaufe there will be 
fome wafte in breaking, the ore is taken out of the lode, and 
brought to grafs in as large lumps as the tackle of the engine will 
mufterf What comes from the people below, is reexamined as 
foon as it arrives at the mouth of the fhaft ; the bell: is broken final! 
with hammers, which they call Spalling, or brought away to the 
adjacent bucking mills, where there are men ready to bruife it upon 
a rock with a fhart bar of iron, and thence carried to the heap of 
beft ore, and what is not worthy of the firft place, is laid by to 
make another fortment ; the bell fmall ore (which conliffs of the 
fmaller fragments of what has been broken and forted before) is 
then walked and lifted into a tub or keeve as near to the fhaft as 
poffible (to prevent wafte), firft through an iron lieve or fearce, 
called in Cornwall the Griddel, the meafhes about half inch fquare ; 
here the wafte, or barren ftone, by walking is difeovered and thrown 
away, and what has copper in it forted into beft , and dredged , (that 
is, ftreaked, fpotted, powdered ore, which requires a fecond walk- 
ing) and the larger pieces of ore of each fortment are thus divided ; 
what paffes through the griddle, is taken up out of the kieve, and 
put through another fearce of fmaller mealk, called the jigging 
fearce, which has eight holes in every fquare inch ; here, when it 
has been lifted up and down, and turned round in the fearce a few 
times (which they call jigging ), the wafte will all rife to the top, 
and fettle in the middle like fmall fand, and what remains under- 
neath will be clean ore. The poorer fort, which is the ftreaked or 
dredged ore, is carried from the mine to the next adjoining ftream 
of water, where in feveral pits made for that purpofe, called the 
ftrakes , it is walhed clean ; all the richeft bits of ore are then culled 
from the reft by girls or boys at the hire of four-pence per day, and 
the pooreft or moft ftony parts, which are not fit to be put with 
the picked ore, are carried to a ftamping-mill, there pounded, and 
paffed through a rough grate s ; what ore refts in the forepart of 
the pit, F, Fig. hi. Plate xix. is carried back to the jigging fearce 
and worked as before-mentioned ; but what runs off to the hinder- 
« Called Under-ground Captains. to raife it entire by the whim, but the beam break- 
f July 1 2, 1 743, I faw a large rock of copper ing, the rock alfo broke in two parts, and the 
taken out of a lode in Clowance wood, which pieces were then brought up. 
weighed 1275 pounds weight : they endeavoured s See (lamping of tin, ch. xv. fe£t. xvii. p. 178. 
moft 
