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ADIT |
A level tunnel (usually driven into a hillside) in order
to give access to a mine, and used for drainage or the
hauling of broken ore. Deeper adits did not necessarily
connect to surface, and were used to carry water back from
distant workings to a pumping shaft. |
|
ANGLE BOB |
A simple lever-based device using which the direction of
a reciprocal motion (of pump rods, flat rods) could be
changed (for example from horizontal to vertical). |
|
ASSAY HOUSE |
The mine laboratory, where samples or ore were analysed
for their mineral content. |
|
BAL or BALL |
From Cornish "Pal" a shovel, and hence
"a digging" = a mine. Generally applied to earlier
mines. See also WHEAL. |
|
BALANCE BOB |
A large counterweighted lever attached to the shaft pump
rods and used to offset their weight and thus reduce the
work of a pumping engine to lifting water alone. A surface
balance bob would be mounted adjacent to the shaft on a pair
of plinths or on a masonry support at ground level (balance
bob mounting), the attached counterweight - a large box
filled with scrap iron or rocks - working in an adjacent
stone-lined pit. Other balance bobs would be installed in
chambers cut into the rock adjacent to the shaft wall as
needed to counterbalance the weight of the pump rods,
especially on a deep shaft.. |
|
BAL-MAID |
A woman or girl employed at surface on a mine, generally
in the dressing of ore. |
|
BEAM-ENGINE |
A type of steam-engine much favoured in Cornwall for use
in pumping, winding, and providing the power to crush ores
preparatory to dressing on Cornish mines. The power from a
large cylinder set vertically in an engine-house was
transferred via a massive rocking beam or bob to the pumps
in the shaft outside. For winding and crushing, the bob was
instead attached to a flywheel and crank on a LOADING next
to the BOB-WALL (or in the case of all indoor engines, the
side wall). In most cases, the engine house formed an
integral part of the framing of the engine. |
|
BEDSTONE |
The granite slab which formed the foundation for the
cylinder of a Cornish Engine. |
|
BLOWING-HOUSE |
An early form of tin smelting furnace, small in scale and
using charcoal as a fuel. |
|
BOILER HOUSE |
A generally lightly-built structure attached to an engine
house, and designed to contain the horizontal boilers for a
steam engine; the associated chimney stack may be attached
to this structure, or built into one corner of the engine
house. |
|
BRATTICING |
Timber partition work in a mine, for instance the LAGGING
BOARDS which lined the upper section of a shaft where it ran
through soft ground. |
|
BUCKING |
The breaking down of copper ore on an anvil to about 10mm
in diameter by bal-maids using small hammers, after which
the ore was separated from the waste by hand. This process
followed cobbing, in which it had been broken down to about
25mm in diameter, the waste again being hand removed. These
processes, through which the majority of the highest quality
copper ore was recovered, took place within roofed
structures called bucking houses. |
|
BUDDLE |
A device for concentrating tin ore. In the mid-19th
century these most usually took the form of a circular pit
with rotating brushes; the tin from the stamps was fed into
the centre or side of the pit and was graded by gravity,
concentrating the heavy ore near the inlet point. These were
often mechanically worked. Earlier buddles were trapezoidal
in shape, and manually operated. A variation used in
tailings works to treat sands and slimes was the ROUND
FRAME: a free-standing, all wooden, mechanically-actuated
buddle, whilst a further variation was the dumb buddle or
dumb pit, which were not mechanically operated. |
|
CALCINER |
A furnace and heating chamber in which ores were roasted
to drive off impurities such as sulphur and arsenic. These
were also known as Burning Houses, later patterns being of
REVERBERATORY design. The Brunton pattern calciner,
introduced in the mid-19th century, was mechanically
powered, and operated on a continuous basis, unlike earlier
designs. Other patterns of calciner were also devised, the
majority named after their designers (eg Oxland, Hocking and
Loam). |
|
CAPSTAN |
A manually or steam-operated winding drum, usually
installed on a mine to raise pitwork from the shaft for
maintenance or repair. |
|
CATARACT PIT |
(or cock pit) A sub-floor area within the foundation
levels of an Engine house between the Cylinder Plat and the
Bob Wall, containing the regulating apparatus, and giving
access to cylinder hold-down bolts. |
|
CILL |
The base of a window or other wall opening. |
|
COFFIN or GOFFEN |
The narrow excavation resulting from stoping on a lode
being carried to or from surface on part or all of a lode.
See also GUNNIS, STOPE, OPENWORK. |
|
CONDENSER |
The cast-iron cylinder set in a tank of cold water
immediately in front of the bob wall of an engine house in
which the exhaust steam was condensed, creating a vacuum
which greatly increased the efficiency of a steam engine.
For a pumping engine this equipment was often contained
within a pair of masonry walls projecting from the bob wall
towards the shaft. |
|
COUNT HOUSE |
Properly ACCOUNT HOUSE, but generally shortened. The mine
office, sometimes incorporating accommodation. |
|
CULVERT |
A small tunnel constructed to carry a channel of water. |
|
CYLINDER OPENING |
The often large, arched opening in the rear wall of an
engine through which the steam cylinder was brought into an
engine house during the erection of the engine. This opening
was generally subsequently closed off with a timber
partition and usually incorporated the principal doorway
into the engine house. |
|
CYLINDER PLAT |
The massive masonry base on which the cylinder of a
Cornish Engine was bolted down (see also BEDSTONE). |
|
DRESSING |
The concentration of the tin (copper or other ores)
contained in the rock excavated from the stopes of a mine.
Carried out on DRESSING FLOORS. |
|
DRESSING FLOORS |
An (often extensive) area at surface on a mine where the
various processes of concentration of ore took place - these
consisted of crushing or stamping to attain a uniform size
range, sizing (particularly on later mines), separation of
waste rock, concentration (generally mechanically and
hydraulically on tin mines, manually on copper mines), the
removal of contaminant minerals (by calcination, flotation,
magnetic separation), and finally drying and bagging for
transportation to the smelter. Tin floors in particular were
generally laid out down a slope to reduce mechanical or
manual handling between stages in the process. |
|
DRIVE |
(alternatively lode drive or heading). A tunnel excavated
on the line of a lode as the first stage of the development
of a STOPE. |
|
DRY or CHANGE HOUSE |
(earlier MOOR HOUSE) The building within which miners
changed their clothes before and after going underground.
Some were heated by steam pipes connected to the engine
boilers. Where there were large numbers of women or children
employed on a mine, there might be two drys - one for men,
the other for women and children. The pithead baths or
showers found in collieries were rarely found in Cornwall. |
|
DUMP or BURROW (alternatively spoil dump, spoil tip). |
A pile of waste material, usually from a mine or quarry.
May contain primary waste (where this could not be disposed
of underground) or waste from various stages in the dressing
process. TAILINGS LAGOONS stored the extensive slimes from
the final stages in the process; in earlier mines these were
flushed over cliffs or allowed to wash away in streams or
rivers. |
|
EDUCTION PIPE |
The large diameter pipe through which exhaust steam was
drawn into the condenser set outside the bob wall. |
|
ENGINE HOUSE |
A building designed to contain steam, gas, oil or
electric engines on a mine or other works. When forming part
of the framework of a beam engine, these were particularly
strongly constructed. |
|
FINGER DUMP |
A linear dump of waste material from a mine or quarry,
flat-topped to allow material to be barrowed or trammed
along it, and often equipped with a temporary tramway track. |
|
FLAT RODS |
Reciprocating (or very occasionally rotative) iron rods
used to transfer power from a steam-engine or water-wheel to
a remote location. |
|
FLUE |
A masonry-constructed tunnel or conduit connecting a
furnace to a chimney stack |
|
GIRDER |
The massive timber beam set across an engine house just
below top floor level to which the parallel motion was
attached and on which the spring beams sat. |
|
GUNNIS |
A narrow linear excavation left where a lode has been
worked, most commonly used when open to surface. See COFFEN |
|
HEAD or CROP |
The richest part of material in a buddle - nearest its
feed point. |
|
HEADFRAME |
The tall construction set over a winding shaft which
carried the sheave wheels over which the winding ropes ran.
Headframes usually contained ore bins or ore chutes to allow
the broken rock in the skips or kibbles to be tipped into
trams at surface. |
|
HORIZONTAL ENGINE |
A steam engine where the cylinder(s) are set on a
horizontal bed and the piston rods are attached via a
cross-head to a crank and flywheel. |
|
HORSE WHIM |
Similar to a capstan, but in this case power supplied by
a horse walking around a circular platform (PLAT) was
applied to an overhead winding drum; frequently used for
winding from small shafts on Cornish mines, especially
during exploratory work and shaft sinking. The smaller
under-gear whims found in some 19th century farms were
little used on mines. |
|
JIG |
A large mechanically or hand-operated sieve set in a tank
of water using which ore could be separated by waste.
Sometimes constructed in groups within jigging houses. |
|
KIBBLE |
A large, strongly-constructed, egg-shaped, iron container
used for ore and rock haulage in earlier shafts. Superseded
by SKIPS. |
|
LAGGING BOARDS |
The timber planks lining the upper part of a shaft, or
where it ran through soft ground. |
|
LAUNDER |
A wooden or steel trough used to carry water or other
liquids; often used to feed water or finely-divided material
in suspension around a dressing floor. |
|
LABYRINTH (colloquially "lambreth") |
A series of interconnected masonry-constructed chambers
set adjacent to one another on whose walls the arsenic
vapourised in a calciner or arsenic furnace was condensed
out. The gas followed a zig-zag path through such groups of
chambers, and one end of each chamber would be closed off
with a door through which the condensed arsenic could be
collected. |
|
LEAT |
An artificial water-course, built to carry a supply of
water to a mine. |
|
LINTEL |
The horizontal timber or stone support above an opening
in a wall or structure. |
|
LOADING |
The masonry platform in front of an engine-house (or
elsewhere on a mine) on which machinery such as cranks,
flywheels or winding drums were mounted and on which the
reciprocal motion of the sweep rod attached to the beam was
turned into a rotative motion. |
|
LOBBY |
The excavated cutting running up to an adit portal. |
|
LODE |
A linear area of mineralisation underground. In other
parts of Britain a VEIN, or SEAM. Generally vertical or
near-vertical, and often extending for considerable
distances along its strike. |
|
LODE-BACK PIT |
A shallow shaft dug from surface into shoad or the upper
part (backs) of a lode, from which ore could be extracted
from shallow stopes to the depth of the water table or just
below. Waste material was generally dumped adjacent to the
shaft mouth. |
|
MAGAZINE |
Small strongly built store containing explosives
(gunpowder or dynamite); often circular, sometimes with
additional enclosing walls to contain the blast of an
accidental explosion. |
|
MELLIOR STONE |
The granite bearing stone in which the upright shaft of a
HORSE WHIM ran. |
|
MIDDLES |
The material in a buddle found between the crop and the
tailings, this generally containing enough ore to warrant
its re-treatment. |
|
OPENWORK or BEAM. |
A mineral extraction site open to the surface, and
similar to a quarry but usually distinguished by its
elongated shape, and steep sides. Generally applied to
features broader in extent than a GUNNIS OR COFFIN. A
variety is a STOCKWORKS, where an area of ground containing
a large number of small parallel lodes was removed
wholesale. |
|
OVERBURDEN |
The topsoil and subsoil removed in the process of opening
or extending a quarry, streamworks or mine. |
|
PELTON WHEEL |
A small enclosed water turbine, working at high pressure
and rotational speeds. In use from the later 19th century. |
|
PITWORK |
The term used to describe the pump rods, rising main,
shaft guides (buntings) etc. within a shaft. |
|
PORTAL |
The entrance to an adit beyond its LOBBY. Often timbered
or stone vaulted. |
|
PROSPECTING PIT FOSSICKING PIT OR COSTEANING PIT |
A small pit dug in search of minerals, and almost always
found in linear groups, often arranged cross-contour, or at
right angles to the projected strike of known lodes or
deposits of shoad. A COSTEANING TRENCH is a linear
excavation cut for prospecting purposes. |
|
RAG FRAME or RACK FRAME |
A mechanically vibrated inclined table-like surface on
which very fine slimes in slurry form were treated to
recover their tin. Large mines would have hundreds of such
frames arranged in groups. |
|
REVERBERATORY KILN |
A design of furnace in which there was indirect contact
between the heat from a hearth and ore to be roasted,
usually by incorporating a baffle flue. |
|
ROSE |
The cast-iron strainer attached to the bottom lift of
pumps. |
|
ROTATIVE ENGINE |
A beam engine in which the reciprocating motion of the
beam was converted to rotary motion via a sweep rod, crank,
and flywheel. |
|
SETT |
The legal boundary within which a mine could extract
minerals. |
|
SETT |
One of a series of stone supports for a tramway,
performing the same function as sleepers. |
|
SETT |
One of the components of timber framing of an adit where
it ran through loose ground; also the timber framing of a
shaft to which the shaft guides and LAGGING BOARDS were
attached. |
|
SHAFT |
A vertical or near-vertical tunnel sunk to give access to
the extractive areas of a mine. |
|
SHAKING TABLE |
An inclined, mechanically vibrated table on which fine
tin (as sands or slimes) in suspension in water was
concentrated by relative density. |
|
SHEARS or shear legs. |
A tall timber frame carrying a pulley or sheave wheel
erected in front of an engine house over a shaft and used
for the installation and maintenance of PITWORK. |
|
SHOAD or SHODE |
Ore weathered from the load and moved (in geological
time) downslope under the force of gravity. Material
reaching a river valley would be to some degree concentrated
before redeposition in horizontal beds. These beds of
detrital material (placer deposits) were exploited in
streamworks. |
|
SKIP |
A (generally elongated) iron or steel container equipped
with small wheels or brackets running on the shaft guides
(buntings) and used for rock and ore haulage in later mines. |
|
SPRING BEAMS |
The pair of longitudinal timbers extending from the rear
of an engine house parallel to and on either side of the
BEAM at top floor level. These served to arrest any unwanted
excess indoor motion of the beam via catches set onto its
rear and were extended out from the front of the house to
form the foundation for the bob-plat (the timber platform
from which the bearings on the outdoor section of the beam
could be serviced). |
|
STACK |
A chimney on an industrial site, used to carry away smoke
or fumes from boilers, furnaces and calciners. Often
situated at the end of a Flue. |
|
STAMPS |
A mechanical device for crushing ore-bearing rock to a
fine sand. Heavy vertically-mounted beams (or later iron
rods) carrying cast or forged iron heads were sequentially
lifted and dropped onto the prepared ore beneath them by a
series of cams mounted on a rotating drum; this usually
being driven by a water-wheel or rotative steam engine. |
|
STOPE |
Excavated area produced during the extraction of
ore-bearing rock. Often narrow, deep and elongated,
reflecting the former position of the lode. Where open to
the surface, these form GUNNISES or COFFENS. |
|
STREAMWORKS |
An area worked for detrital (redeposited) tin deposits by
shallow excavation. Often characterised by linear dumps,
river diversion, and evidence for leats. Some streamworks
(dryworks) exploited deposits of shoad in now dry valleys
and on hillsides, where concentrations of this material were
economically workable. Leats and reservoirs were necessary
to work these sites, and are characteristic of them. |
|
STRIPS (settling strips) |
Elongated shallow tanks in which the primary settlement
and subsequent separation of tin ore from waste took place
after it had been stamped. |
|
SWEEP ROD |
The elongated iron rod which connected the beam of a
Cornish engine to a crank and fly wheel. |
|
TAILINGS |
The waste sand and slime from a mine dressing floor, not
containing workable quantities of mineral. |
|
TAILRACE |
The channel along which water flows after having passed
over or under a water-wheel and is then generally returned
to the water course. |
|
TRIBUTE |
A system of payment in which groups of miners bid against
one another for contracts to work sections of the mine for a
percentage of the value of the ore raised from that area. |
|
TUTWORK |
A system of payment whereby groups of miners contracted
to work on a "payment by results" system at
previously-agreed rates, usually for shaft sinking or
driving levels. |
|
VANNER |
A mechanically-driven, laterally vibrated, inclined
rotating belt on which fine tin-containing material in
suspension in water was treated by relative density. A
VANNING SHOVEL was used to test the relative concentration
of ore in a sample of finely crushed ore or partially
dressed ore. |
|
WATER-WHEEL |
Wheel fitted with buckets or paddles around its
periphery, and driven by the weight or force of a stream of
water directed onto them. |
|
WHEAL also WHELE, WHILE, HUEL. |
A mine. |
|
WHEELPIT |
A structure built to house a water-wheel, often excavated
and stone-lined, but sometimes free-standing. |
|
WHIM PLATFORM |
The level and usually circular platform on which a
horse-whim was sited. |
|
WHIM |
The winding gear used for hauling from a shaft; consists
of a power source and a winding drum. See Horse-Whim. |
