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judge rapper

The upper end of the vertical arm of a judge. See also:judge
Fay

Judson powder

A blasting explosive containing sodium nitrate, sulfur, coal, and a little
nitroglycerin. Webster 2nd

jug

A colloquial equivalent of seismic detector, geophone, etc.
See also:geophone

jugglers

Timbers set obliquely against pillars of coal to carry a plank partition,
making a triangular air passage or manway. Fay

julienite

Possibly a tetragonal mineral, Na2 Co(SCN)4 .8H2 O ;
a blue thiocyanate that may be an artifact.

jumble

Derb. The place where veins intersect. Fay

jumbler

Big Jumbler, a bed of limestone in the Lower Lias at Rugby, United
Kingdom.

jumbles

The thickest oolitic bed in the Carboniferous limestone of the Clee Hills,
Shropshire, United Kingdom.

jumbo

a. In mining, a drill carriage or mobile scaffold on which several drills
of drifter type are mounted. It is used in tunnels and large headings.
Pryor, 3
b. An asbestos-fiberizing machine that is effective for moderately soft
ore where crushing or breaking is not required. Sinclair, 7
c. A mobile scaffold to assist drilling in large headings. BS, 12
d. A number of drills mounted on a mobile carriage and used in tunnels.
Nichols, 1
e. Drilling platform used in tunneling. Sandstrom

jump

a. See:jumping a claim
b. A sudden rise in the dip of a coal seam. Arkell

jump correlation

Identification of events on noncontiguous seismic records as involving the
same interfaces in the Earth. AGI

jumper

a. The borer, steel, or bit for a compressed-air rock drill. CTD
b. A long steel bar, or light aluminum tube with a steel end, used to
dress rock faces, pry off loose rock, etc. Pryor, 3
c. Person who jumps a claim; i.e., takes possession of another's mining
property. Pryor, 3
d. A steel bar used in manual drilling. Sandstrom

jumper bar

A weighted steel bar with a cutting edge; raised and dropped by hand.
CTD

jumping a claim

a. Taking possession of a mining claim liable to forfeiture owing to the
requirements of the law being unfulfilled.
b. Taking possession of a mine or claim by stealth, fraud, or force.
Syn:jump
c. The act of locating a mining claim on supposed excess ground within
staked boundaries of an existing claim on the theory that the law
governing the manner of making the original location had not been complied
with. Fay

jump sheet

A flat metal plate used as a turnsheet on which to turn the empty cars.
Lewis

junckerite

See:siderite

junction

a. The point where two or more passageways intersect horizontally or
vertically. AGI
b. In ventilation surveys, where three or more airways meet.
Roberts, 1
c. The union of two lodes. Gordon

junction box

In mining, a stationary piece of enclosed apparatus from which one or more
electric circuits for supplying mining equipment are connected through
overcurrent protective devices to an incoming feeder circuit.

junk

a. Any foreign metallic material accidentally introduced into a borehole.
Long
b. Very poor or low-grade drill diamond. Long

junkerite

See:siderite

junket

a. Eng. A bucket used for raising rock or ore in a shaft. Hess
b. Eng. See:kibble