A foot he progressed into the foot wall and changed drills.

Three inches more.

Then-- "Harry!" "What's 'appened ?" The tone of Fairchild's voice had caused the Cornishman to lean from his staging and run to Fairchild's side.

That person had cupped his hand and was holding it beneath the drill hole, while into it he was pulling the muck with the scraper and staring at it.
"This stuff's changed color!" he exclaimed.

"It looks like--" "Let me see!" The older man took a portion of the blackish, gritty mass and held it close to his carbide.