Horizontal entrance into mine, sometimes called a day level, its main purpose being to drain water from the workings.
A deposit of sand, mud, tin stone etc., formed by flowing water.
This term normally refers to oxide of arsenic and may be crude arsenic or arsenic soot (impure) or refined or white arsenic (99% pure As2O3).
AUGER or Archimedean Screw
Device For propelling thick slurry along or up a conduit.
Counterpoise to take part of the weight of the pump rod in a shaft.
Device for reducing ore to small particles.
Barium sulphate, BaSO4, principal barium ore.
Set of stamps which could comprise as few as two individual stamps to as many as 64 or more.
See Rocker Bob.
See Cornish Pump.
See Ore Bin.
Oxide of tin, SnO2, the end product of the ore-dressing processes in a tin mine.
See Rocker Bob.
Usually either Cornish (horizontal with single fire tube extending along its length) or Lancashire (two parallel fire tubes side by side).
A small shaft furnace similar to a limekiln, used for arsenic burning in the early days of the industry. Such a furnace existed at Devon Great Consols but is something of an enigma as it was built as recently as 1924 and its flue leads directly into the main flue to the stack without going through the arsenic-condensing chambers.
Low partition between fire and hearth in reverberatory furnace.
Tramroad rails whose section resembled an inverted letter U with exaggerated outer serifs.
Simple circular and square buddles used for separating tin ore from waste. In a circular concave buddle the pulped ore was fed in at the circumference and flowed inwards towards the centre.
Old term for building where ore was calcined or “burnt”. See also under Calciner.
CAGE or Skip
Box-like container which could be raised or lowered in shaft to convey men, ore, etc. Usually ran in guides termed cage (or skip) roads.
A furnace in which ore was roasted either to drive off unwanted constituents or to sublimate them for separate recovery or to render the ore more amenable to subsequent processes. Could be an ordinary reverberatory furnace or a Brunton calciner. The latter type had a slowly revolving circular bed played on by flames from peripheral furnaces. Ore was fed onto the centre and automatically raked towards the circumference as calcining proceeded until it fell into a cooling chamber below. Other varieties existed. See also Bottle Furnace.
Mine superintendent or manager.
Tin dioxide, SnO2, the principal tin ore.
See Condensing Chambers.
Final stage in the concentrating of tin ore.
Device for sizing very small ore-particles in which pulped ore was fed into the top of a downward-pointing cone against an upward-flowing current of water, fine particles being carried up and overflowing from the top of the cone, coarser particles overcoming the current and falling to the bottom where they could be drawn off through a spigot.
See Shaft Collar.
Ore which has been freed of waste.
CONCENTRATING TABLE or Shaking Table
Usually a rectangular table about 16 feet long and 6 feet Wide given a special vibrating motion which caused particles on it to progress along its length while a stream of water tended to wash them across the table. But along its length were many low parallel strips or riffles of diminishing heights over which the lighter material was washed while the heavier particles stayed between the riffles to reach the end of the table. Many varieties existed under various trade names - Wilfley, James, Record etc.
A labyrinth of connecting compartments in a flue in which arsenical vapour was condensed into either crude or refined arsenic.
Abbreviation of “Consolidated” and a common suffix to mine names, intended to inspire confidence in prospective investors.
Many varieties exist but the most common locally was Copper Pyrites, a sulphide of copper and iron, CuFeS2.
Achieved by leading copper-impregnated mine water over scrap iron on which metallic copper was deposited for subsequent recovery.
Typically a single-cylinder steam engine with its piston rod pointing upwards and connected to one end of a pivotted beam, the other end of which could be connected to pump rods in a shaft if a rise and fall motion was required or to a crank if rotary motion was called for. Cylinders could be of enormous size - up to 90 inches or more in diameter while steam pressure was low by modern standards - usually round about 40 p.s.i. See also Parallel Motion.
CORNISH PUMP or Beam Pump
A simple force-pump sited at shaft bottom and connected to a power source at surface by a vertical rod, water being forced up to the surface or to adit level through a rising main or “pump column”. See also Cornish Engine and Balance Box.
A packed meal eaten at the mine.
A vein, usually non-metalliferous, making an obtuse angle with adjacent lodes.
A level driven at an obtuse angle to the lode(s) in a mine.
Or Jaw-crusher or Rock Breaker. Device as commonly used in quarries for reducing relatively large pieces of ore to roadstone size.
A mixture of anthracite and coke used for firing calciners.
A covered leat.
Modern equivalent of a cone-type classifier, involving a swirling motion of its contents.
See Raft Wheel.
Areas where ore was treated.
A horizontal tunnel, the excavating of such a tunnel being referred to as Driving.
Miners' changing house with facilities for drying wet clothing.
For drying ore, as opposed to calcining it.
See Raft Wheel.
Those that are derived by in situ weathering or weathering plus gravitational movement or accumulation.
The end of a drive or crosscut.
Unit used in mines. 1 fathom equals 6 feet.
Horizontal wood or metal rods for transmitting power a distance by means of a to-and-fro motion.
See Dressing Floors.
FLOTATION or Froth Flotation
A modern method of ore-separation which relies on the fact that if air bubbles are introduced into a mixture of water and pulped ore some minerals will adhere to the bubbles and be carried up to the surface while others will not and will therefore sink to the bottom.
Access openings in flues, especially arsenic flues.
Ladders leading down a shaft, or may imply the shaft itself.
A reference to pumping, i.e. “Forked to bottom” meaning all water pumped out of the mine.
Machine for pulling tramwagons up an incline.
A fairly modern ore-separating device consisting of a wide rubber belt stretched between two slowly-revolving rollers, the upper surface moving in a slightly uphill direction with a stream of water flowing down it. Pulped material was fed onto the belt, heavier ore particles surviving the flow of water to reach the top, lighter waste being washed to the bottom. Fell into disuse mainly due to limited capacity.
Lead sulphide, PbS, and the principal lead ore. Usually contained a small proportion of silver, when it was termed silver-lead.
Non-metallic waste rock accompanying the ore in a lode.
Simple headgear over a shaft.
Simple device for sizing rough ore, consisting of a sloping grill of iron bars onto which the ore was tipped, pieces which failed to fall through being passed to a rock-breaker for further reduction.
Rotted and decomposed granite.
An oxide of iron, Fe2O3, a commonly worked iron ore.
A small reservoir at the point where water from a leat was passed into a pipeline leading down to a turbine or pelton wheel, built to prevent air getting into the pipeline and to intercept sand, gravel and other debris.
Timber or steel frame over shaft carrying pulleys for winding ropes.
The richer product from an ore-dressing device, as opposed to the poorer product, the “tails” or “tailings”.
A short flue between a calciner and arsenic condensing chambers, too hot for deposition of arsenic but in which flue dust was intercepted.
A type of rotary pulveriser in which rollers were spun round against an outer casing by centrifugal force, crushing any ore within the casing.
Sloping tramway, usually cable-operated.
A shaft sunk at a relatively flat angle, with a tramroad leading down it.
JIGGER or Jig or Jig Washer
Device in which gravel-sized material was formerly shaken up and down in a sieve under water, heavy ore forming a layer at the bottom with lighter waste above it. In later versions the sieve stayed still while the water pulsated up and down and the device was also made to be continuous-acting.
Barrel-shaped iron bucket for hoisting ore up shaft.
Wooden tub, sometimes called a chimming kievc, used in final stage of tin ore dressing.
Mechanical hammers for striking chimming kieves to aid settlement of concentrate.
See Slime Pond.
Receiving kibbles of ore at the shaft head.
Open wooden conduit for taking water to a waterwheel or carrying pulverised ore in suspension from one ore-dressing device to another.
Open watercourse for conducting water across country from river to waterwheel, etc.
Horizontal tunnel in mine not extending to the open air.
Masonry or concrete support for a heavy machine, e. g. a set of stamps.
A vein containing a proportion of mineral ore which had to be freed from the waste rock accompanying it.
Electrical device for separating magnetic from non-magnetic ore.
General term for building housing stamps, ore-dressing machinery, etc.
Arsenical iron pyrites, FeAsS, the principal arsenic ore in the district.
Powerful jet of water for washing out alluvial ore.
Iron Pyrites, or iron sulphide, FeS2. was vapourised in a “vapour chamber" before being ignited in the cylinder.
A quarry-like excavation along the line of a lode.
A large container for stockpiling ore prior to feeding it to the stamps, etc.
Processing ore to separate it from the waste rock accompanying it.
The line where a lode reaches the surface of the ground.
An early chemical process for separating tin ore from tungsten ore, which were both heavy minerals not readily dealt with by normal gravitational methods.
An ingenious arrangement for connecting the top of the piston rod of a Cornish pumping engine (which moved up and down in a straight line) with the inner end of the pump beam (which moved in an arc of a circle).
Water-driven power source consisting of a wheel with cups round its circumference acted on by a powerful jet of water issuing from a nozzle. Needed a head of water of 100 feet or more and speed of wheel could exceed 500 r.p.m.
PICKING HOUSE or - shed or - floor
Place where ore was sorted by hand.
Store for explosives usually sited some distance from mine buildings, etc.
Made by passing air and steam over a bed of glowing coal or other combustible matter to produce carbon monoxide and hydrogen. The air and steam were drawn through the producer by the induction strokes of the gas engine, hence the alternative term “suction gas”.
A trial excavation dug with a view to starting up a mine.
PULP or pulped ore
Pulverised ore usually carried along by running water from one ore-dressing device to another.
Rudimentary steam device for pumping from very shallow mines merely consisting of two chambers, two non-return valves and a differential valve.
PULVERISER or Grinder
Machine, of which many varieties existed, for reducing ore to a finely divided state.
Large iron pipe, consisting of individual sections bolted one to another for conveying water up a shaft to surface or to adit level.
Wooden or metal rod connected to a power source at surface down to a pump in the shaft. See also Balance Box.
Manganese dioxide, MnO2, principal manganese ore in the district.
Stirring ore being roasted in a furnace.
RACK FRAME or Ragging Frame
A development of the square buddle which was continuous-acting so could work unattended.
RAFT WHEEL or Dipper Wheel or Elevator
Sometimes spelt Raff. In effect a waterwheel in reverse, which if turned by mechanical means would raise up waterborne pulped ore so that it could be put through the ore-dressing processes a second time.
A simple furnace in which crude arsenic, or “arsenic soot” was roasted again, fumes from which were condensed to produce pure “white arsenic”.
Burnt residue from roasting ore in calciner or other furnace.
ROCKER BOB or Rocker Beam or Bob or Beam
Massive pivotted beam connected at one end to a power source, e.g. piston rod of a steam engine and at the other to a line of pump rods in a shaft, or to a crank if rotary motion was required.
ROLLS or Cornish Rolls
Parallel revolving rollers between which ore was crushed when fine crushing was not needed.
A development of the circular buddle in which the bed itself revolved, pulp being fed onto it at one point, waste was washed off at a second point and concentrated ore at a third point, so that it was continuous-acting.
Perforated metal or woven wire sieve, either vibrating rectangular or revolving cylindrical, for sizing ore fragments.
The area of ground owned or leased by a mine.
SETTLING PIT or Settling Tank
Tank, usually rectangular and of concrete, where waterborne ore could settle and be dug out after the water accompanying it had been drained off.
More or less vertical entrance to a mine. Could be for pumping from (usually termed Engine Shaft), for hoisting from (sometimes termed a Whim Shaft), for access by ladders (termed Footway Shaft), or for ventilation.
Timber or masonry structure round top of shaft to prevent loose ground collapsing inwards.
See Concentrating Table.
Timber structure at shaft head carrying a pulley, used for raising or lowering heavy equipment in the shaft.
SLIME POND or Lagoon
Pond where waste slime could be settled rather than be carried into neighbouring rivers.
Round Frame or Concentrating Table designed to deal specifically with slimes.
Ore so finely divided as to be difficult to recover completely.
SLUICE BOX or Strip
Long wooden launder with low crosspieces placed at intervals along the bottom ofit. Ore and waste was allowed to flow along it in suspension, heavy particles tending to settle against the crosspieces while water and lighter material flowed over them.
Wooden platform in or over a shaft. When mines were abandoned shafts were sometimes “sollared over” and the sollar covered with rubble, making such sites dangerous today with the rotting of the sollars with consequent risk of collapse into the shaft.
Breaking up large pieces of ore with sledge hammers.
See Wash Tower.
Devices for crushing lode material to the consistency of sand as a first step towards separating mineral ore from waste rock. Various types existed (Cornish, Californian, Holman's Pneumatic, etc.) the simplest form amounting to vertical stems or “lifters” with their lower ends heavily shod with iron, each being alternately lifted by pegs on a revolving drum and allowed to drop on material in a mortar box.
Excavation of ore underground was referred to as stoping and the place where it was carried out as a stope. Removing ore from the roof of the stope was referred to as overhand or back stoping while taking it from the floor (the less usual method) as underhand stoping.
Surface tin works in which water was used to separate the tin ore from previously weathered deposits.
See Sluice Box.
Working platform or staging erected to facilitate access to the upper part of a stope.
See Producer Gas.
See Concentrating Table.
Leat or conduit taking water away from a waterwheel, etc.
TAILINGS or Tails
The poorer product from an ore-dressing device, as opposed to the richer product, the “Heads”.
See Dressing Floors.
TRAMROAD or Tramway
Narrow gauge mine railway, either above or below ground.
Revolving sieve for sizing ore fragments.
TURBINE or Water Turbine
Power source in which a flow of water was used to turn an enclosed spindle to which vanes were attached. Could be designed to work from a head of water of only a foot or so up to several hundred feet at rotor speeds of about 40 r.p.m. upwards.
TURNBOB or Angle Bob
Arrangement for changing the direction of flat rods or pump rods, resembling a large bell crank.
Earthy brown ore containing iron and manganese and used for paint manufacture, etc.
See Frue Vanner.
A special shovel with a rather broad flat blade used by prospectors or as a ready means of checking the products of ore-dressing appliances. Water and crushed material are put on the blade which is then given a combined jerking and swirling motion which causes the heavier particles to separate out from the waste.
A chamber between the end of an arsenic flue and the stack containing blocks of limestone kept wet by water from a sprinkler and intended to reduce the emission of noxious gases from the stack.
Common source of power, in use in almost every traditional mine and usually of the “overshot” variety, water being fed to the upper part of the wheel, its weight in the “buckets” causing the wheel to revolve. Speed of rotation slow - up to 15 r.p.m. for small wheels down to only 4 r.p.m. or so in the biggest. Made in all sizes, up to 50 or more feet in diameter.
Prefix meaning mine which in earlier days was spelt Huel.
Masonry pit in which a waterwheel was sited.
WHIM or Hoist or Winder
Machine for hoisting from a shaft, Whim being the older term, driven by any convenient power source, and usually provided with an indicator so that the engineman could be kept aware of the position of the cage in the shaft.
Vertical shaft within a mine, but not extending to surface.
Tungsten ore, tungstate of iron and manganese, (Fe,Mn)WO4, the chief source of tungsten in the district.