A glossary of mining and metallurgical terms

A GLOSSARY OF MINING AND METALLURGICAL TERMS. 81
iSjjIU. 1. To divide a ventilating current. 2. When a partinf/
in a coal-seam becomes so thick that the two portions of the seam
must be worked separately, each is called a split. See Bench.
Sponge. Metal in a porous form, usually obtained by reduction
without fusion. See Chenot p7'ocess.
Spoon. 1. An instrument made of an ox or buffalo horn, in which
earth or pulp may be delicately tested by washing to detect gold,
amalgam, etc. 2 (or Spoon-end). The edge of a coal-basin when
the coal-seam sjjoons, I. e., rises to the surface, after growing thinner
as it approaches its termination.
Spout, S. Staff. See Air-head.
Sprctff. 1. A prop). 2. A short round piece of wood used to
block the wheels of a car.
Spreade)\ A horizontal timber below the ca^j of a set, to stiffen
the legs, and to support the brattice when there are two air-coui*ses
in the same gangway.
Spreadei^s. Pieces of timber stretched across a shaft as a tempo-
rary support of the walls.
Sprue. A piece of metal attached to a casting, occupying the gate
or passage through whicirthe metal was poured.
Spud. A nail, resembling a horseshoe nail, with a hole in the
head, driven into mine-timbering, or into a wooden plug inserted in
the rock, to mark a surveying-station.
Spur. A branch leaving a vein, but not returning to it.
Spurns, S. Staff, Small connecting masses of coal, left for
safety during the operation of cutting, between the hanging coal and
the main bod3'.
ore.
Square sets. A kind of timbering used in large spaces.
Squat, Corn. 1. Tin-ore mixed with spar. 2. See Bunch of
Squeeze. The settling, without breaking, of the roof over a con-
siderable area of workings.
Squeezer. A machine for reducing the puddle-ball to a compact
mas.s, ready for the haqjmer or rolls.
Squib. A slow-match or safety-fuse, used with a barrel.
Squirting. Forcing lead by hydraulic pressure into the form of
rods or pipes.
Stack. 1. A chimney. 2. See Shaft-furnace.
Stall, S. Staff. See Room, Breast, and Fost-and- Stall.
Stamping. Keducing to the desired fineness in a stamp-mill. The
grain is usually not so line as that produced by grinding in pans.
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