TOL. VI.] PHILOSOPHICAL TRANSACTIONS. 5^$ 



more washed with a trambling shovel, and so it new-names the ore, black tin, 

 I. e. such as is completely ready for the blowing-house. 



We have another more curious way, termed sizing, that is, instead of a draw- 

 ing huddle, we have a hair sieve, through which we sift, casting back the re- 

 mainder into the tails, and then new tramble that ore. After the second tram- 

 bling we take that forehead in the second huddle, and dilve it {i. e. by putting 

 it into a canvas sieve, which holds water, and in a large tub of water lustily 

 shake it) so that the filth gets over the rim of the sieve, leaving the black tin 

 behind, which is put up into hogsheads covered, and locked till the next 

 blowing. 



The tails of both buddies, after two or three tramblings, are cast out into the 

 first strake, or tie, which is a pit purposely made to receive them ; and what 

 over small tin else may wash away in trambling. There are commonly three 

 /or four of them successively, which contain two sorts of tin ; the one^ which is 

 too small, the other too large. The latter is new ground in a crazemill (in all 

 respects like a greistmill wit*h two stones, the upper and the nether) and after 

 that trambled in order. The former is dressed on a reck, with the shovel and 

 water, and made fit to be used. A reck is a frame made of boards about three 

 feet and a half broad, and six long, which turns upon two iron pegs fastened in 

 both ends, and the whole placed upon two posts, so that it hangs in an equili- 

 brium, and may like a cradle be easily removed either way. 



T/ie Manner and TVay of Blowing Tin, 



Conceiving it sufficient to say, that our furnace is no other than an alman 

 furnace, I shall proceed (only taking notice, that our lime, though the strongest 

 I ever yet heard of, as being made of the hardest marble, will not endure the 

 fire in our hearth, but we must use a particular kind of clay) to describe a tin- 

 kiln, whose structure is four square. At the top is a large moor stone about six 

 feet long, four broad ; in the middle thereof is a hole made about half a foot 

 diameter. This stone serves as a head or cover to another like stone, placed 

 about a foot beneath it, but is not so long by half a foot as the upper, because 

 it must not reach the innermost or back part of the wall, which is the open 

 place through which the flame ascends from a lesser place below that, where a 

 very strong fire of furze is constantly made, and another little square hole on 

 the outside, for a purpose soon to be mentioned; the fore part is like a com- 

 mon oven, and has a similar chimney in the fore part. 



Now when we perceive much mundic in our tin, (which spoils it by making 

 it brittle and not malleable) which we easily discern before knacking, we are 

 necessitated to burn away this weed in the kiln, thus: All the black tin (brouglit 



