Note 14 — BOOK XI.

If we assume Roman weights, the charge in the first case can be tabulated as follows, and for convenience will be called the fifth charge:—

5th Charge (3 cakes).

Amount of copper211.8 lbs.

Amount of lead635.4 lbs.

Weight of each cake282.4 lbs.

Average value of charge218 ozs. 18 dwts.

Per cent. of copper25%

Average value of original copper per ton583 ozs. 6 dwts. 16 grs.

Weight of argentiferous lead liquated out494.2 lbs.

Average value of liquated lead per ton352 ozs. 8 dwts.

Weight of residues353 lbs.

Average value of residues per ton20 ozs. (about).

Extraction of silver into the argentiferous lead94%

The results given in the second case where the copper contains 2 librae and a bes per centumpondium do not tie together at all, for each liquation cake should contain 3 librae 9¹/₂ unciae, instead of 1¹/₂ librae and ¹/₂ uncia of silver.