Mine.
1. A subterraneous passage from which coal, metals, metallic ores, are obtained.| Depth of Mines. | Feet. |
| Eselchact, Bohemia (silver). | 3,778 |
| Dunkenfield, England (coal) | 2,504 |
| Pendleton, England (coal) | 2,504 |
| Linden, Prussia (salt well) | 2,331 |
| Tresavean, England (copper) | 2,112 |
| Durham, England (coal) | 1,773 |
| Valenciana, Mexico (silver) | 1,686 |
| Crown Point, Comstock lode, Nevada (silver) | 1,400 |
| Santa Rosa, Mexico (silver) | 1,200 |
3. (Fortification.) An excavation toward or under the rampart of a fortress to contain an explosive charge, to destroy or effect a breach in an enemy's works. Mines executed by the defenders of a fort, to intercept those of the assailants, are countermines. The place of deposit is the chamber; and the passage leading thereto the gallery. Military mines are known as, — Common. Double. Triple. Defensive or countermines. Offensive. Conjunct, several acting simultaneously. Suffocating or camonflet. Undercharged. Over or surcharged, producing a crater whose radius is greater than the line of least resistance. Military mining was practiced in very early times. It is represented in the Assyrian sculptures. The Persians and Romans adopted it extensively; the latter as early as the fifth century B. C. They had no explosives. Herodotus mentions the Persian mines during the siege of Barca in Libya, and the skillful countermining of the garrison. (iv. 200.)
