VOL. II.] PHILOSOPHICAL TRANSACTIONS. 277 



fathoms. Their best reaks are north and south: east and west are good, though 

 not so deep. The groove is 4 feet long, 2 j- feet broad, till they meet a stone, 

 when they carry it as they can. The groove is supported by timber of different 

 thickness as the place requires. A piece of an arm's thickness will support 10 

 ton of earth. It lasts long: that which was put in above 200 years since will 

 serve again in new works. It is tough and black, and being exposed to the sun 

 and wind for two or three days, will scarcely yield to an axe. For the supply of 

 fresh air there are boxes of elm exactly closed, of about fix inches in the clear, 

 by which they carry it down above 20 fathoms. When they come at ore, and 

 need an air shaft, they sink it at 4 or 5 fathoms distant, and of the same fashion 

 with the groove, to draw 'ore as well as air. They make use of leathern bags, 

 eight or nine gallons a-piece, drawn up by ropes to draw up the water. If they 

 find a swallet, they drive an adit on level, till it is dry. If they cannot cut the 

 rock, they use fire to anneal it, laying on wood and coal, and the fire is so con^ 

 trived that they leave the mine before the operation begins, and find it danger- 

 ous to enter again, before it be quite cleared of the smoke, which has killed 

 some. Their beetles, axes, wedges, unless they be so hardened as to make a 

 deep impression upon the head of an anvil, are not fit for their use ; and yet 

 they sometimes break them in an hour; others last three or four days. They 

 work in frocks and waistcoats, by tallow candles, 14 or 15 to the pound, each 

 whereof lasts three hours, if they have air enough ; which if they want to keep 

 in the candle, the workmen cannot stay there. When a vein is lost, they drive 

 two or three fathoms in the breast, as the nature of the earth directs them. They 

 convey out their materials in elm buckets drawn up by ropes, the buckets hold- 

 ing about a gallon. Their ladders are of ropes. 



The ore runs sometimes in a vein, sometimes dispersed in banks. It lies 

 often between rocks : some of it is hard, some milder. They never find any 

 perfect, but it must be refined. They have often branched ore in the spar. 



There is about the ore some substances of spar and chalk, and another sub- 

 stance, which they call the crootes, which is a mealy white stone, marted with 

 ore, and soft. The spar is white, transparent, and brittle like glass. The chalk 

 white and heavier than any stone. The vein lies between the coats, and is of 

 diff'erent breadths. It breaks off sometimes abruptly in an earth, called a dead- 

 ing bed, and after a fathom or two may come to it again, keeping the same point 

 or direction. It terminates sometimes in a dead clayey earth, without croot or 

 spar; sometimes in a rock called a fore- stone. The clearest and heaviest ore 

 is the best; of which 36 hundred weight may yield a ton of lead. They beat 

 the ore with a flat iron; then cleanse it in water from the dirt; and sift it 

 through a wire sieve. The ore tends to the bottom, and the refuse lies at top. 



