| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Hard bottom | Mining | A condition encountered in some open-cut mines wherein the rock occasionally will not be broken down to grade because of an extra-hard streak of ground or because not enough explosive is used. This is called a "hard bottom"; it interferes with work and puts undue strain on a shovel. Such unbroken ores usually are drilled with a jackhammer and blasted. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
