An exploder approved for firing six shots simultaneously in British coal
mines. It contains a 67-1/2-V high-tension dry battery, used to charge a
150-mu F condenser, which in turn is discharged through the shotfiring
circuit by a firing key. The test circuit and an ohmmeter are incorporated
in the exploder, thc ohmmeter pointer moving over a scale to indicate
whether or not the external circuit is in order. A pushbutton disconnects
the test circuit from the external circuit and makes connection with the
firing circuit. See also:blasting machine
See:bog iron; bog iron ore; limonite.
Moistureless; dry and rough to the touch, such as chalk and magnesite.
Nelson
An arithmetic average of a series of values; esp. arithmetic mean.
CF:mode
The numeral that represents the average between the greatest strength of
double refraction and the least strength of double refraction possessed by
a species or variety. The refractive index of sphene, e.g., is 1.885 to
1.990 and 1.915 to 2.050; hence the birefringence ranges from 0.105 to
0.135. The average, or mean, is 0.120. Syn:refractive index
One-hundredth of the heat required to raise 1 g of water from 0 degrees C
to 100 degrees C. Newton, 1
The cross-sectional area of a stream divided by its width at the surface.
AGI
a. One of a series of regular, freely developing sinuous curves, bends, or
loops in the course of a stream. It is produced by a mature stream
swinging from side to side as it flows across its floodplain or shifts its
course laterally toward the convex side of an original curve. Etymol:
Greek maiandros, from Maiandros River in western Asia Minor (now known as
Menderes River in SW Turkey), proverbial for its windings. AGI
b. To wind or turn in a sinuous or intricate course; to form a meander.
AGI
That part of a floodplain between two lines tangent to the outer bends of
all the meanders. It is the zone within which channel migration occurs, as
indicated by abandoned channels, accretion topography, and oxbow lakes.
A line run in a survey of a mining claim bordering on a stream or other
body of water, not as a boundary of the tract surveyed, but for the
purpose of defining the sinuosities of the bank or shore of the water, and
as a means of ascertaining the quantity of land within the surveyed area.
Ricketts
In an air compressor, the equivalent average pressure exerted by the
piston throughout a stroke. Lewis
mean radiant temperature (mrt)
Single temperature of all enclosing surfaces that would result in the same
heat emission as the same surface with various different temperatures.
Strock, 2
a. The index of refraction measured for the D line of sodium.
b. For uniaxial crystals: (2nomega +nepsilon )/3. For
biaxial crystals: (nalpha +nbeta +ngamma )/3.
The weighted average particle size of any sample, batch, or consignment of
particulate material. BS, 5
The uniform depth to which water would cover the Earth if the solid
surface were smoothed off and parallel to the surface of the geoid.
Generally accepted as a depth of 2,440 m. Hy
a. In fatigue testing, the algebraic mean of the maximum and minimum
stress in one cycle. Also called the steady-stress component.
ASM, 1
b. In any multiaxial stress system, the algebraic mean of three principal
stresses; more correctly called mean normal stress. ASM, 1
The apparent depth of a borehole as measured along the longitudinal axis
of the borehole. The measured drilling depth is always equal to the
unoverlapped drilled footage in a borehole. Also called measured depth.
Sometimes abbreviated md. Long
Resources from which the quantity is computed from dimensions revealed in
outcrops, trenches, workings, or drill holes; grade and/or quality are
computed from the results of detailed sampling. The sites for inspection,
sampling, and measurement are spaced so closely and the geologic character
is so well defined that size, shape, depth, and mineral content of the
resource are well established. See also:reserves
The finding of the number of units of measure in a line, area, space or
volume, period of time, etc. Jones, 2