326 CAVE AND CLIFF DWELLERS. 
the old mines of immense masses of 
rock and dirt which had accumulated 
during many decades of abandonment, 
“ gutting and scalping,” as the miners 
say. Recently over one hundred miles 
of openings have been made. The 
most important is the great Porfirio 
Diaz tunnel, to be miles in 
length when completed—one of the long¬ 
est and most important mining tunnels in 
the world, cutting over sixty well-known 
veins at the river’s level. No one can 
look at the great mills, the aque¬ 
duct of enormous masonry (eight or 
nine miles long, and that will 
take up all the water of the Batopi- 
las river), or the town of Batopilas (a most 
active place of six thousand people) 
without respecting the energy that has 
accomplished all this. The history of 
