a. Rock formation in which the joints, cracks, or crevices are sealed and
impermeable to water. Long
b. Rock composed of tightly cemented grains of very fine, even-sized
crystals. Long
c. Rock that does not chip easily under the impact of cable tools.
Long
d. A tough, resilient rock. Long
e. Can. Without evidence of shearing or mineralization.
Syn:tight formation
A quarrymen's term, equivalent to blind seam, or incipient joint.
Fay
The most complete sheathing using wood timbering. Used where water or fine
wet soils must be retained. The frame is designed for this use and is
generally stronger than that required for other types of sheathing. A
specially edged plank, generally tongue-and-grooved, eliminates the
crevices existing in close sheathing. CF:close sheathing;
skeleton sheathing. See also:tight lagging
An explosive shot that has been set off to loosen coal in a seam that has
not been previously cut or sheared. BCI
A monoclinic mineral, CaMg(AsO4 )F ; isomorphous with isokite;
violet-gray; at Laangban, Sweden, and Kajlidongri, Central India.
Copper obtained by roasting and refining the metal bottoms that collect
under the regulus in smelting certain impure ores; usually cast in flat,
rectangular plates, hence its name. See also:bottoms
Standard, 2
A machine for making tubular or arch-shaped tiles from clay, operating by
forcing the raw material through a die, in a continuous stream, which is
cut into suitable lengths by wires. Standard, 2
An earthy variety of cuprite, brick red because of admixed iron oxides.
a. A kiln or oven for baking tiles. Standard, 2
b. A maker or layer of tiles. Standard, 2
A device that permits laying tile directly behind a ditcher. Also called
tile box. Nichols, 1
A tilery or tile field. Standard, 2
Beds of calcareous sandstone or ironstone, near Hastings, England.
Fay
Dominantly unsorted and unstratified drift, generally unconsolidated,
deposited directly by and underneath a glacier without subsequent
reworking by meltwater, and consisting of a heterogeneous mixture of clay,
silt, sand, gravel, and boulders ranging widely in size and shape.
See also:boulder clay; moraine. Syn:glacial till; ice-laid drift.
AGI
A flexible wire rope composed of six small ropes, usually of seven wire
strands each laid about a hemp core. Zern
A monoclinic mineral, Ca5 (Si2 O7 )(CO3 ) (sub
2) ; forms white grains in rock at Crestmore, CA.
A consolidated or indurated sedimentary rock formed by lithification of
glacial till, esp. pre-Pleistocene till (such as the Late Carboniferous
tillites in South Africa and India). AGI
a. The angle at the perspective center of an aerial photograph between the
plumb line and the perpendicular from the interior perspective center to
the plane of the photograph. AGI
b. The lack of parallelism (or the angle) between the plane of the
photograph from a downward-pointing aerial camera and the horizontal plane
(normal to the plumb line) of the ground. AGI
c. In aerial photography, the angle between the lens axis and a vertical
through the exposure station (rear nodal point of lens). It is seldom more
than 3 degrees and can generally be kept to 1 degrees . This is regarded
as satisfactory for vertical photographs. Seelye, 2; Hammond
d. To hammer or forge with a tilt hammer; as, to tilt steel to render it
more ductile. Standard, 2
A hammer for shingling or forging iron, arranged as a lever of the first
or third order, and tilted or tripped by means of a cam or cog gearing and
allowed to fall upon the billet, bloom, or bar. Fay
A bulldozer whose blade can be pivoted on a horizontal center pin to cut
low on either side. Nichols, 1
Open-hearth furnace swung about its major axis when pouring out the melted
product. Pryor, 3
A crest gate for dam spillways designed so that water pressure acting upon
it will do so only at a definite level. It closes automatically when the
water level falls to normal. Hammond