A boosting charge placed in contact with a detonator to ensure detonation
of the main charge. BS, 12
A term used for mercury produced by mines.
Low grade of virgin zinc containing about 98% zinc, 1.60% lead, 0.08%
iron, with no limitations on cadmium or aluminum. Bennett
a. The act of placing a detonator in an explosive charge. Pryor, 3
b. The act of adding water to displace air, thereby promoting suction, as
in a suction line of a pump. Water used to promote initial suction in a
centrifugal or reciprocating pump.
See:primer
A coating of binder applied to a surface of natural compacted or
stabilized soil before surface dressing. Nelson
A tube containing fulminating powder for firing a charge. A detonator.
Standard, 2; Fay
a. A safety valve on the working cylinder of a steam engine to discharge
the priming. Standard, 2
b. A valve connected with the discharge pipe of a force pump through which
the pump may be primed. Fay
See:primitive circle
In crystallography, the great circle on a stereographic projection that
represents the equator of the spherical projection. The poles of all
vertical crystal planes plot on the primitive. Syn:primitive
Fay
A crystal form from which other forms may be derived; e.g., a
hexoctahedron has six faces replacing each octahedral face.
See:unit cell
Roofing slate sized 24 in by 14 in (61 cm by 36 cm). Pryor, 3
Primary, or leading function. A principal axis is the longest one in a
crystal. The principal valence is that at which an element forms the
greatest number of stable compounds. Pryor, 3
a. In the tetragonal and hexagonal systems, the vertical crystallographic
axis; hence what is the same thing in uniaxial crystals, the optic axis.
In the orthorhombic and triclinic crystals, the axis of the principal
zone; the axis with the shortest period, often the axis of the principal
zone. In monoclinic crystals, the axis c, usually the axis of the
principal zone excluding the symmetry axis; the symmetry axis b.
Fay; AGI
b. That crystallographic axis with unique symmetry in a crystal system,
designated c, except in the monoclinic system where the second setting is
used by mineralogists making b the unique axis.
c. In a transducer used for sound emission or reception, a reference
direction for angular coordinates used in describing the directional
characteristics of the transducer. It is usually an axis of structural
symmetry or the direction of maximum response, but if these do not
coincide, the reference direction must be described explicitly. Hy
d. In experimental structural geology, a principal axis of stress or a
principal axis of strain.
One of the three mutually perpendicular axes of the strain ellipsoid.
One of the three mutually perpendicular axes that are perpendicular to the
principal planes of stress. See also:principal axis
A central meridian on which a rectangular grid is based; specif. one of a
pair of coordinate axes (along with the base line) used in the U.S. Public
Land Survey system to subdivide public lands in a given region. It
consists of a line extending north and south along the astronomic meridian
passing through the initial point and along which standard township,
section, and quarter-section corners are established. The principal
meridian is the line from which the survey of the township boundaries is
initiated along the parallels. AGI
The moment of inertia of an area about either principal axis.
Roark
The geometric center of an aerial photograph, or the point where the
optical axis of the lens meets the film plane in an aerial camera. Symbol:
p. See also:fiducial mark