BOOK VIII.

347

a great number of deep ditches in rows in the gullies, slopes, and hollows ofthe mountains. Into these ditches the water, whether flowing down fromsnow melted by the heat of the sun or from rain, collects and carries togetherwith earth and sand, sometimes tin-stone, or, in the case of the Lusitanians,the particles of gold loosened from veins and stringers. As soon as thewaters of the torrent have all run away, the miners throw the material outof the ditches with iron shovels, and wash it in a common sluice box.

A— Gully. B— Ditch. C— Torrent. D— Sluice box employed by the

Lusitanians.

The Poles wash the impure lead from venae dllatatae in a trough tenfeet long, three feet wide, and one and one-quarter feet deep. It is mixedwith moist earth and is covered by a wet and sandy clay, and sofirst of all the clay, and afterward the ore, is dug out. The ore is carriedto a stream or river, and thrown into a trough into which water is admittedby a little launder, and the washer standing at the lower end of the troughdrags the ore out with a narrow and nearly pointed hoe, whose wooden handleis nearly ten feet long. It is washed over again once or twice in the sameway and thus made pure. Afterward when it has been dried in the sun