As the danger of a fall of material from the roofs of the adits and galleries was well understood, it was customary to support them by means of wooden posts, or, where the material was sufficiently firm, to arch them.[1034] Still, from time to time, falls would occur, with great injury and loss of life to the miners.

Nor was there much less danger where a mountain was quarried for the sake of its metallic treasures.
Here, too, galleries were driven into the mountain-side, and portions of it so loosened that after a time they detached themselves and fell with a loud crash into a mass of _debris_.[1035] It sometimes happened that, as the workings proceeded, subterranean springs were tapped, which threatened to flood the mine, and put an end to its further utilisation.
In such cases, wherever it was possible, tunnels were constructed, and the water drained off to a lower level.[1036] In the deeper mines this, of course, could not be done, and such workings had to be abandoned, until the invention of the Archimedes' screw (ab.

B.C.

220-190), when the water was pumped up to the surface, and so got rid of.[1037] But before this date Phoenicia had ceased to exist as an independent country, and the mines that had once been hers were either no longer worked, or had passed into the hands of the Romans or the Carthaginians.
When the various ores were obtained, they were first of all crushed, then pounded to a paste; after which, by frequent washings, the non-metallic elements were to a large extent eliminated, and the metallic ones alone left.

These, being collected, were placed in crucibles of white clay,[1038] which were then submitted to the action of a furnace heated to the melting point.