discharging into the river Liris (Garigliano). 30,000 men were employed; time occupied, 11 years. A large number of shafts were sunk to allow a greater number of men to work and to facilitate the removal of detritus.
It is from 20 to 30 feet high and 28 to 30 feet wide.
That which drained the waters of Lake Albano was cut through lava, about 6 feet high 3 1/2 feet broad, and 6,000 feet long.
50 shafts were sunk, and the work was prosecuted at many points, being completed in one year, 398 B. C. A water tower was erected at each end, and these, together with the arched conduit, are in good condition yet.
The stone mountain of Gibraltar is tunneled into galleries, from whose embrasures peep the grim cannon which defend the bay and the neutral ground.
Quite a change since Gibraltar, Gebel el Tarik, Tarik's Mountain, was the scene of the landing of this lieutenant of the Emir Musa, April, A. D. 711.
Musa the Saracen conquered Spain.
The galleries in the rock are nearly 3 mites