Mark Twain,
Roughing It — Chapter XXIX
(1872)
“ When the explosion came and the rocks and smoke shot into the air, we would go back and find about a bushel of that hard, rebellious quartz jolted out. Nothing more. One week of this satisfied me. I resigned. Clagget and Oliphant followed. Our shaft was only twelve feet deep. We decided that a tunnel was the thing we wanted.So we went down the mountain side and worked a week; at the end of which time we had blasted a tunnel about deep enough to hide a hogshead in, and judged that about nine hundred feet more of it would reach the ledge. ”
