A glossary of mining and metallurgical terms

56 A GLOSSARY OF MINrXG AND METALLURGICAL TERMS.
3IaUet, Corn. The sledge-hammer used for striking or healing the
borer.
Mandril. See 3Iaundril.
31anganese-oreii. Gray oxide (pyrolusite, polianite, a.nhy(\rous per-
oxide, and manganite, hydrated sesquioxide) ; black manganese (hauts-
mannite, protoperoxide) ; braunite (anhydrous sesquioxide); red
manganese ore irhodochrosite, a carbonate, or rhodonite, a silicate)
also, manganiferous iron ores.
Man-hole, Corn. The hole in a sollar through which men pass
upon the ladder or from one ladder to the next.
3Ian-machine or Man-engine, Corn and Derb. A mechanical lift
for lowering and raising miners in a shaft by means of a recipro-
cating vertical rod of heavy timber with platforms at intervals, or
of two such rods, moving in opposite directions. In the former
case, stationary platforms are placed in the shaft, so that the miner
in descending, for instance, can step from the moving platform at
the end of the down-stroke, and step back upon the next platform
below at the beginning of the next down-stroke. When two rods
are employed, the miner steps from the platform on one rod to that
on the other.
Man-of-war, Staff. A small pillar of coal left in a critical spot
also, a principal support in thick coal workings.
3Ianta, Sp. Blanket ; sack of ore.
Mantle. The outer wall and casing of an iron blast furnace, above
the hearth.
Manway. A small passage, used by workmen but not for trans-
portation.
3Iaquilla, Sp. A mill where ore is ground on shares.
3Iarl. Calcareous clay, sometimes used for the hearths of cupel-
ling-furnaces.
3Iartin process. Called also the Siemens-Martin and the open-
hearth process. See Steel.
31ass-copper, Lake Sup. Native copper, occurring in large
masses.
3Iassicot. See Litharge.
Matrix. The rock or earthy material containing a mineral or
metallic ore ; the gangue.
3Iatt, or 3Iatte, Fr. A mass consisting chiefly of metallic sulphides
got in the fusion of ores.
3Iaal, Derb. A large hammer or mallet.