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BOOK XL 



sooner they are broken up ; the less hot, the longer it takes, for now and 

 then they bend into the shape of copper basins. When the first cake has 

 been broken, the second is put on to the other fragments and beaten untU it 

 breaks into pieces, and the rest of the cakes are broken up in the same manner 

 in due order. The head of the hammer is three palms long and one wide, 

 and sharpened at both ends, and its handle is of wood three feet long. 

 When they have been broken by the stamp, if cold, or with hammers if hot, 

 the fragments of copper or the cakes are carried into the store-room for 

 copper. 



A— Back wall. B — Walls at the sides. C — Upright posts. D — Chimney. 

 E — The cakes arranged. F — Iron plates. G — Rocks. H — Rabble with two 



PRONGS. I — Hammers. 



The foreman of the works, according to the different proportions of 

 silver in each centumpondium of copper, alloys it with lead, without which 

 he could not separate the silver from the copper.^" If there be a moderate 



^"The details of the preparation of liquation cakes — " leading " — were matters of great 

 concern to the old metallurgists. The size of the cakes, the proportion of silver in the original 

 copper and in the liquated lead, the proportion of lead and silver left in the residual cakes, all 

 had to be reached by a series of compromises among militant forces. The cakes were generally 

 two and one-half to three and one-half inches thick and about two feet in diameter, and 



