ABSTRACT
HOWEVER, adapting themselves to these perilous conditions, the miners who search for metals, fearful of such dangers but not routed by them, leave frequent arches to hold up the rock and set up wooden props from the sides of the mountains inwards, to ensure their own safety. They rely on the doubtful stability of these, but they have contrived yet another method: those who intend to hack out metals or select lodes of silver let themselves down on ropes among rocks where they cannot walk; afterwards they apply their skill to these minerals and clear them out with fire and water.1
