418

BOOK IX.

If the tin is so impure that it cracks when struck with the hammer, itis not immediately made into lattice-like bars, but into the cakes which I havespoken of before, and these are refined by melting again on a hearth. Thishearth consists of sandstones, which slope toward the centre and a littletoward a dipping-pot; at their joints they are covered with lute. Drylogs are arranged on each side, alternately upright and lengthwise, and moreclosely in the middle ; on this wood are placed five or six cakes of tin whichall together weigh about six centumpondia ; the wood having been kindled,

A —Hearths. B —Dipping-pots. C —Wood. D —Cakes. E —Ladle. F —Copperplate. G —Lattice-shaped bars. H—Iron dies. I—Wooden mallet. K —Mass

OF TIN BARS. L—SHOVEL.

mu

the tin drips down and flows continuously into the dipping-pot whichis on the floor. The impure tin sinks to the bottom of this dipping-potand the pure tin floats on the top ; then both are ladled out by the master,who first takes out the pure tin, and by pouring it over thick plates of coppermakes lattice-like bars. Afterward he takes out the impure tin from whichhe makes cakes ; he discriminates between them, when he ladles and pours,by the ease or difficulty of the flow. One centumpondium of the lattice-likebare sells for more than a centumpondium, of cakes, for the price of the former