A pit or excavation In the earth, from which metallic ores or other mineral substances are taken by digging. Webster; Marvel v. Merritt, 110 U. S. 11, 6 Sup. Ct. 207, 29 L. Ed. 550; Murray v. Allred, 100 Tenn. 100, 43 S. W. 355, 39 L. R. A. 249, 60 Am. St Rep. 740.