Show the uncovering of a 12 foot ledge of ore of good commercial grade is reported in ill virgin ground in the lucky hill estate at candelaria nevada As the leading coal producing state pennsylvania sets a good example 1 in n the small tonnage that is won by the powder without being previously undercut or sheared in 1913 the quantity of coal reported to the united states geology geological ical survey tice of 0 ve y as mined by the dangerous practice cc shooting off the solid was less than per cent of the total output |