Emergency, crude repair of a bit made by a drill runner at the drill site.
Long
The first energy to arrive from a seismic source. First arrivals on
reflection records are used for information about a surficial low-velocity
or weathering layer; refraction studies are often based on first arrivals.
Syn:initial impulse; first break. AGI
See:weight break; first arrival.
a. A diamond with a faint greenish tint. Schaller
b. A classification of gem diamond.
A bar having a fulcrum (pivot point) between the points where force is
applied and where it is exerted. Nichols, 1
An ore of sufficiently high grade to be acceptable for shipment to market
without preliminary treatment. CF:second-class ore
Syn:shipping ore
In the room-and-pillar method, the part of the coal that is won from the
rooms, as distinguished from the second part, which is the extraction of
the remaining pillars. Stoces
See:selenite plate
See:gypsum plate
e$ 0 0 ݼ DICTIONARY TERMS:first ripping The ripping work carried out as the r
[\B]first ripping[\N]
Gems, particularly diamonds, of the highest value, irrespective of size.
In diamonds, the term applies to stones that are flawless, without color
or almost bluish white. A slight amount of color detracts from the value,
and the stones are said to be off color.
Rift; reed; cleavage way. See also:easy way
The first indication of roof pressure that takes place after the removal
of coal from a seam. CTD
The removal of the coal in driving the entries and rooms.
See also:advance working
A long, narrow arm of the sea; also, the opening of a river into the sea.
Along the Scottish coast, it is usually the lower part of an estuary
(e.g., Firth of Forth), but sometimes it is a fjord (e.g., Firth of Lorne)
or a strait (e.g., Pentland Firth). Etymol. Scottish. Syn:frith
AGI
A rotary bit in which a number of cutting edges are arranged behind a
pilot bit to enlarge the hole to the required diameter. BS, 12
Hydrogenation of carbon monoxide to form hydrocarbons from coal or natural
gases. Pryor, 3
a. To join two beams, rails, etc., by long pieces at their sides.
Zern
b. The article recovered and/or the act or processes involved in the
recovery of lost drilling tools, casing, or other articles from a
borehole. Also called fishing. Long
A rail joint made by means of fishplates. Hammond
An apparatus using a gas-permeability method for determination of the
average particle diameter of powders. A sample, equal in weight (grams) to
the true density of the material, is compacted between two porous plugs in
a metal tube, to a known porosity. Air or a suitable gas, under a constant
pressure head, is passed through the compressed sample, and rate of flow
is measured by a calibrated flowmeter. The average particle diameter of
the powder is indicated directly on a self-calculating chart by the liquid
height in one arm of the flowmeter tube. No dispersion is required, and
the results are unaffected by particle shape. Osborne
a. A little-used name for moonstone, also for opal with a girasol effect.
b. A popular trade term for any transparent faceted stone so cut that its
center is lacking in brilliancy.
c. A diamond cut too thin to present the maximum effect of brilliancy.
See:apophyllite