A hole drilled for the purpose of splitting a block of stone. These holes
are usually in rows. The plug is a slightly wedge-shaped piece of iron
driven between two L-shaped irons, or feathers, inserted in the hole.
Stauffer
A method used in quarrying to reduce large masses of stone to smaller
size. By using a hammer drill, a row of shallow holes is made along the
line where a break is desired. The feathers consist of two iron strips
flat on one side for contact with the wedge, and curved on the other to
fit the wall of the drill hole. They are placed in the hole and the plug
(a steel wedge) is placed between them. They are sledged lightly in
succession until a fracture appears. Wherever possible, such fractures are
made parallel with the rift of the stone. Syn:multiple wedge
See also:plug
a. A diamond bit that grinds out the full width of a hole.
Nichols, 1
b. A noncoring diamond-set bit that can be in the form of a bullnose bit,
pilot bit, or concave bit. Also called bullnose bit; concave bit; noncore
bit; pilot bit. BS, 9
Eng. A wooden water pipe used in coffering.
A stonecutter's percussion drill. Webster 3rd
a. A borehole that has been filled or capped with a long plug, or in which
a plug has been inserted. Long
b. Cracks or openings in the rocks in the walls of a borehole that have
been filled or sealed with cement or other substances. Long
c. A borehole that has been drilled with a plug or noncoring bit.
Long
d. A blocked core barrel or bit. Long
e. A coring bit in which a plug has been inserted. See also:plug
Long
a. See:noncoring bit
b. A core bit, the annular opening of which is tightly closed or blocked
by a piece or the impacted fragments of a core. Long
A curb supporting the walling in a shaft and is itself supported on plugs
or bolts driven into the ground around the shaft. The crib may be removed
when the walling from below is carried up to it. See also:strata bolt
Nelson
a. The stopping of the flow of water into a shaft by plugs of clay.
Zern
b. The material used, the act, or the process of inserting a plug in a
borehole to fill it or the cracks and openings in the borehole sidewalls.
Long
c. The act or process of drilling a borehole with a noncoring bit.
Long
d. The practice of filling holes and cavities in castings with porous
silicate mixture (cast iron filler) before the application of cover coats.
The filler must be firmly forced into the casting holes, since any
entrapped air beneath the filler will expand during firing and force the
material out causing blowholes. Enam. Dict.
a. A passageway that is left open, while working on an explosion-proof
stopping, for the purpose of maintaining the ventilation of the fire area
at or as near the normal quantity as possible, to prevent any increase in
the combustible gases content in the air. After the stopping is completed,
this hole is plugged up with sandbags in order to completely seal off the
mine area. The plughole is generally a tapered passageway of about 3.5 ft
(1.1 m) square at the inby side of the stopping and 2.5 ft (0.76 m) square
at the outby side. McAdam, 1
b. See:block hole
A stopping in which the floor and the sidewalls of the passage are built
of sandbags, and the roof may be the roof of the roadway or covering
boards used between the webs of steel arches, or preferably, corrugated
steel sheeting used as lagging behind steel arches. The plughole or
passage is generally tapered from the inby end from 3 to 3.5 ft (0.9 to
1.1 m) square to 2.5 ft (0.76 m) square so that, in the event of an
explosion, the plug of sandbags in the passage is subjected to a wedging
action assisting to retain the plug in place. The plughole may be placed
in the most convenient position and although this is often at the top, it
is sometimes placed to the side and reasonably near the floor.
Sinclair, 1
See:pumping engineer
Scot. A small charge exploded in a hole to break up a stone of moderate
size.
A valve or cock opened or closed by the turning of a plug, usually conical
in shape. Not to be confused with needle valve or globe valve.
Long
a. A large random-shaped stone dropped into a large-scale mass of concrete
to economize on the volume of the concrete. Hammond
b. An old form of plumb. Fay
a. See:vertical
b. See:plumb bob; plumbline.
c. To carry a survey into a mine through a shaft by means of heavily
weighted fine wires hung vertically in the shaft. The line of sight
passing through the wires at the surface is thus transferred to the mine
workings. An important piece of work: in mine shafts, and in transferring
courses or bearings from one level to another. Fay
a. A special quality of powdered graphite used to coat molds, and in a
mixture with clay, to make crucibles.
b. See also:black lead; graphite.
c. Impure graphite or graphitic rock.
d. Minerals resembling graphite; e.g., molybdenite.
Highly refractory crucible composed of a mixture of about equal parts of
refractory clay and graphite. Osborne
a. A small weight or bob, hanging at the end of a cord, which under the
action of gravity is oriented in a vertical direction. Also called a
plummet. CTD
b. A pointed weight hung from a string. Used for vertical alignment.
Nichols, 1
A soft sealing compound for pipe threads. Nichols, 1
Of, pertaining to, or containing lead, esp. in its higher valence.
CF:plumbous