Fine and often unburned dust settling out in steamy, warm conditions in
stagnant situations. Sinclair, 1
a. Cumb. A hematite iron-orebody of circular or oval plan and conical
section, formed in a swallow hole. Arkell
b. Cumb. A nest or pocket of black lead. Arkell
See:Barvoys process
A telescopic self-reading staff dividing into three sections, set one
above the other when the staff is at its full extent of 14 ft (4.3 m).
Graduations are marked in feet, tenths and hundredths of a foot, and the
thickness of the horizontal lines is 0.01 ft (3.05 mm), alternately black
and white. Hammond
An old name for the glassy salbands of small, diabase dikes formerly
regarded as a mineral. It is derived from Sordavala, Finland.
Calcined magnesite or magnesia mixed with a solution of magnesium
chloride. It sets to a hard mass within a few hours. The basis of
artificial flooring cements. CTD
A titanium slag containing about 80% TiO2 . It is made by
electric-furnace smelting of iron-titanium ores. Newton, 1
If differences of temperature are induced in a solution of sodium chloride
or some other substance in water, the dissolved material will become
relatively more concentrated in those portions in which the temperature is
lowest. Fay
A mountain sickness that attacks miners who are newcomers in high
altitudes. Symptoms are headaches, nausea, vomiting, and nosebleed. If the
symptoms do not soon pass, there is nothing to be done except return to a
lower altitude. Hoover
Any type of retention of a material at a surface, esp. when the mechanism
is not specified. Adsorption is then restricted to the physical process
that leads to the formation of a unimolecular surface layer; chemisorption
refers to the corresponding chemical process; and absorption to the
entrance of the sorbed material within the solid. Miall
See:graded
a. In a genetic sense, it may be applied to the dynamic process by which
granular or fragmental material having some particular characteristic,
such as similar size, shape, specific gravity, or hydraulic value, is
selected from a larger heterogeneous mass.
b. The degree of similarity, in respect to some particular characteristic,
of the component parts in a mass of material.
c. A measure of the spread of a distribution on either side of an average.
d. The separation of coal or ore as mined into valuable material and
waste.
e. See:handpicking
a. A coefficient used in describing the distribution of grain sizes in a
sample of unconsolidated material. It is defined as S0 = Q1
/Q3 , where Q1 is the diameter that has 75% of the
cumulative size-frequency (by weight) distribution smaller than itself and
25% larger than itself, and Q3 is that diameter having 25% of the
distribution smaller and 75% larger than itself. Hunt
b. Dimensionless measure for degree of sorting. Schieferdecker
See:emerald triplet
a. The act of striking a mine roof with a metal testing bar to ascertain
whether or not it is strong and safe. Hudson
b. A dam or barrier in a mine in which the frictional resistance to the
passage of water is high. Such a dam permits little water to pass through
it and is said to be "sound." Sinclair, 4
c. Elastic waves in which the direction of particle motion is
longitudinal; i.e., parallel with the direction of propagation. The term
is sometimes restricted to such waves in gases, particularly air, and in
liquids, particularly water, but it is also applied to wave motion in
solids. It is the type of wave motion most often used in
reflection-seismic exploration. AGI
Sound waves in the surface layers of the ocean tend to be refracted
downward due to decrease of temperature with depth. In deep waters the
sound waves are refracted upward by high and increasing pressure, which
has a greater influence on the resulting refractive index of these layers
than the decreasing temperature. The result is the formation at mid-depth
of a wave guide that permits compressional waves of acoustic frequencies
to travel great distances. Hy
a. See:roof testing
b. Rapping on a pillar to signal a person on the other side or to enable
the person to estimate its width.
c. A rough method of judging by sound the direction and distance apart of
two roadways driven in coal to meet each other. The sounding is made by
giving two slow and three sharp knocks on the solid coal, which is
answered in similar manner from the opposite roadway. The method is
sometimes called chap. Nelson
d. Subsurface investigation by observing the penetration resistance of the
subsurface material without drilling holes. This can be done by driving a
rod into the ground or by using a penetrometer. See also:penetrometer;
soil. Long
In measuring water depth, the hand lead used in sounding.
See also:hand lead
A closed pipe, 1 in (2.5 cm) in diameter, with a flush point and a driving
tip, used in sounding. See also:sounding
Tapping the roof with a pick or bar to test its soundness. Korson
In a specified direction at any point, the average rate of sound energy
transmitted in the specified direction through a unit area normal to this
direction at the point considered. Hy