A type of foot operated drill-rod safety clamp, the operation of which is
similar to a bulldog safety clamp. Also called automatic spider.
Long
Applied to metals, such as beryllium, magnesium, titanium, and zirconium,
that were put into expanded use following World War II. Pearl
A term used for agatized wood, esp. agate formed by siliceous
permineralization of wood. AGI
A jig with a plunger compartment at the head end, so that the material is
given a classification in the jig. Liddell
A table of the general Wilfley-Overstrom-Card type, with riffles parallel
to the tailings side, and a hinged portion without riffles (unlike the
Card). The table top is a rhomboid, and the riffles gradually shorten as
they near the tailings side. See also:Wilfley table
S. Staff. A hoisting chain, the iron links of which are filled with small
blocks of wood. Fay
A scale of resistance to abrasion based on the following method: if
specimens of different materials are mounted so that they present surfaces
substantially in the same plane, and if the surfaces are subjected to a
lapping operation with a properly selective abrasive, the harder materials
will stand out in relief, whereas the softer ones will be cut or worn to a
depth, depending upon their hardness. By averaging several readings, a
scale of hardness was established by which the quantitative values of the
hardness of various materials could be determined. On the Woodell scale,
diamond has approx. 2 times the hardness of boron carbide, 3.5 times that
of tungsten carbide, and nearly 5 times that of corundum. Chandler
Consists of wooden staves driven down in soft ground during sinking to
keep back water. The lining is stated to be capable of withstanding
pressures up to a maximum of 130 psi (896 kPa). The lining resembles the
sides of a wooden tub and the word tubbing is doubtless derived from this
similarity. See also:tubbing
A finely radiated variety of hematite exhibiting alternate bands of brown
or yellow of varied tints. Fay
A trigonal mineral, CaAl3 (SO4 )(PO4 )(OH)6 ;
beudantite group; forms small colorless rhombohedra.
A fibrous variety of chalybite (siderite), FeCO3 . Fay
Corn. Fibrous limonite; Land's End district. Arkell
A variety of opal with woody texture by replacement. Syn:opalized wood;
xylopal; lithoxyl.
A method of sinking a shaft through loose surface deposits by driving a
ring of wood piles down vertically. As the piles are rammed downward, the
loose material is removed. Frames are set to prevent the piles being
forced inward. Each new set of piles reduces the dimensions of the
excavation. To avoid this reduction in size, the piles are driven at an
angle away from the shaft space. Nelson
A flotation process utilizing the surface tension of water, either fresh,
acid, or salt.
A variety of asbestos resembling wood. Standard, 2
A monoclinic mineral, (Zn,Mn)Mn3 O7 .H2 O ; related
to todorokite; at Sterling Hill, NJ.
Piping formed from wood boards fitted and strapped together by encircling
steel bands. Pryor, 3
A piece of wood attached to the leg of steel girders to provide a measure
of yield and prevent premature distortion and damage to the ring.
See also:arch girder; stilt. Nelson
See:silicified wood
A nodular variety of cassiterite, or tinstone, of a brownish color and
fibrous structure, and somewhat resembling dry wood in appearance.
Syn:dneprovskite