Book 34
9
There is a fountain in the Heracleum at Gades, the waterA tidal spring at Gades. of which is sweet and is reached by steps. This fountain has a tide which rises and falls exactly in the reverse order of the sea tide. When it is high tide at sea it is low tide in the fountain, and high in the fountain when it is low at sea. The explanation of this is that the wind, which rises from the bowels of the earth to the surface, is prevented from finding its natural egress when the earth is covered with water at the rise of the tide, and being thus turned back into the interior of the earth, it stops up the underground channels of the fountain and produces a deficiency of water; but when the earth is again uncovered, the wind having once more found an easy egress, sets the veins of the fountain free again, and the water spurts up freely.
9
There are very large silver mines about twenty stadesThe process of producing silver in the mines near New Carthage. from New Carthage, extending to a circuit of four hundred stades, in which forty thousand men are continually employed, who produce for the benefit of the Roman people twenty-five thousand drachmae a day. It would take too long to describe the whole process of working them, but I may mention that the alluvial soil containing the silver ore is first broken up, and sifted in sieves held in water; that then the deposit is again broken, and being again filtered with running water, is broken a third time. This is done five times; the fifth deposit is smelted, and, the lead having been run off, pure silver remains. . . .
9
The Anas and Boetis both flow from Celtiberia, their streams being about nine hundredThe Guadiana and Guadalquivir. stades apart. . . .
9
Among other cities of the Vaccaei and Celtiberians are Segesama and Intercatia. . . .
