A glossary of mining and metallurgical terms

32 A GLOSSARY OF MINING AND METALLnRGICAL TERMS.
Dumper. A tilting-car used on (Jumps.
Durn, Corn. A frame of timbering, like a door-frame.
Dust-plate. A vertical iron plate, supporting the slacf-ruuner of
an iron blast furnace,
Dutch metal. An alloy of copper and zinc, containing more copper
than ordinary brass.
Duty. A measure of the effectiveness of a steam-engine, usually
expressed in the naml)ei" of foot-pounds (or kilogram metres) of use-
ful work obtained from a given quantity of fuel.
Duty-ore, Corn. The landlord's share of the ore.
Dyke. See Dike.
Dzhu, Con^s. To cut ahead on one side of a face, so as to increase
the efficacy of blasting on the remainder. (Doubtless the same word
as Dissue. See Dissuing.) Also called to hulk.
Egg-coal, Penn. See Coal.
Egg-hole, Derb. A notch cut in the wall of a lode to hold the
end of a stempel.
Eledrum. An alloy of copper, zinc, and nickel.
Elirpiation. Separating an alloy by heating it so as to melt the
more fusible of its ingredients, but not the less fusible.
Elutriation. Purification by washing and pouring off the lighter
matter suspended in water, leaving the heavier portions behind.
Elvan, Corn. A name given to certain broad granite veins or
belts in schistose rocks.
Eraery. Impure corundum.
End of coal. The direction or section at right-angles to the/«t-e ;
sometimes called the hutt.
End-pieces, Corn. See Wall-plates.
Engli.sh process. In copper-smelting, the process of reduction in a
reverberatory furnace, after roa.'itiiig, if necessary.
English zinc-furnace. A furnace in which zinc is reduced and
distilled from calcined ores in crucibles.
Engorgement. The clogging of a furnace. See Scajf'old.
Entry. An adit. Applied to the main gangway in some coal
mines.
Estufa amalgamation, Sp. A modification of the patio process,
using heat.
E.vploder. A cap or fulminating cartridge, placed in a charge of
gunpowder or other explosive, and exploded by electi'icity or by
a fuse. See Explosives.