Mining in Roman Britain
Encyclopedia
Mining
was one of the most prosperous activities in Roman Britain
. Britain was rich in resources such as copper
, gold
, iron
, lead
, salt
, silver
, and tin
, materials in high demand in the Roman Empire
. The abundance of mineral resources in the British Isles
was probably one of the reasons for the Roman conquest of Britain
. They were able to use advanced technology to find, develop and extract valuable minerals on a scale unequaled until the Middle ages
.
Lead was essential to the smooth running of the Roman Empire. It was used for piping
for aqueducts and plumbing
, pewter
, coffins, and gutters for villas
, as well as a source of the silver that sometimes occurred in the same mineral deposits.
The largest Roman lead mines were located in or near the Rio Tinto (river) in southern Hispania
.In Britannia the largest sources were at Mendip
, South West England
and especially at Charterhouse
. In 49 C.E., six years after the invasion and conquest of Britain, the Romans had the lead mines of Mendip and those of North West England
and Wales
running at full shift. By 70 C.E., Britain had surpassed Hispania
as the leading lead-producing province
. The Spanish soon lodged a complaint with Emperor Claudius, who in turn put limits on the amount of lead being produced in Britain. However, these limits were ignored and had the opposite effect on British lead production.
. The Roman economy was based on silver, as the majority of coins were minted from the precious metal.
The process of extraction, cupellation
, was fairly simple. First, the ore was heated until the lead, which contained the silver, separated from the rock. The lead was removed, and heated up to 1100° Celsius
using hand bellows
. At this point, the silver separated from the lead, and was put into molds which, when cooled, would form ingots that were to be sent all over the Roman Empire for minting.
Britain's gold mines were located in Wales at Dolaucothi
. The Romans discovered the Dolaucothi vein
soon after their invasion, and they used hydraulic mining
methods to prospect the hillsides before discovering rich veins of gold-bearing quartzite
. The remains of the several aqueducts and water tanks above the mine are still visible today. The tanks were used to hold water for hushing
during prospecting for veins, and it involved releasing a wave of water to scour the ground and remove overburden, and expose the bedrock. If a vein was found, then it would be attacked using fire-setting
, a method which involved building a fire against the rock. When the hot rock was quenched with water, it could be broken up easily, and the barren debris swept away using another wave of water. The technique produced numerous opencasts which are still visible in the hills above Pumsaint
or Luentinum
today. A fort, settlement and bath-house were set up nearby in the Cothi Valley. The methods were probably used elsewhere for lead
and tin
mining, and indeed, were used widely before explosives made them redundant. Hydraulic mining
is however, still used for the extraction of alluvial tin
.
Long drainage adit
s were dug into one of the hills at Dolaucothi, after opencast mining methods were no longer effective. Once the ore was removed, it would be crushed by heavy hammers, probably automated by a water wheel
until reduced to a fine dust. Then, the dust would be washed in a stream of water where the rocks and other debris would be removed, the gold dust and flakes collected, and smelted into ingots. The ingots would be sent all across the Roman world, where they would be minted or put into vaults.
and 15% in the Forest of Dean
. Because iron ores were widespread and iron was relatively cheap, the location of iron mines was often determined by the availability of wood for smelting fuel, which Britain had in abundance. Great amounts of iron were needed to fuel the Roman war machine, and Britain was the perfect place to fill that need.
Many underground mines were constructed by the Romans. Once the raw ore was removed from the mine, it would be crushed, then washed. The less dense rock would wash away, leaving behind the iron oxide
, which would then be smelted
using the bloomery
method. The iron was heated up to 1500°C using charcoal. The remaining slag
was removed and generally dumped.
After being smelted, the iron was sent to forges, where it was reheated, and formed into weapons or other useful items.
The majority of mine workers were slaves, although skilled artisans were needed for building aqueducts and leat
s as well as the machinery needed to dewater mines and to crush and separate the ore from barren rock. Reverse overshot water-wheel
s were used to lift water, and sequences of such wheels have been found in the Spanish mines. A fragment of a wheel found at Dolaucothi shows they used similar methods in Britain.
The working conditions were poor, especially when using fire-setting
, an ancient mining method used before explosives became common. It involved building a fire against a hard rock face, then quenching the hot rock with water, so that the thermal shock
cracked the rock and allowed the minerals to be extracted. The method is described by Diodorus Siculus
when he discussed the gold mines of Ancient Egypt
in the first century BC, and at a much later date by Georg Agricola
in his De Re Metallica
of the 16th century. Every attempt was made to ventilate the deep mines, by driving many long adit
s for example, so as to ensure adequate air circulation. The same adits also served to drain the workings.
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
was one of the most prosperous activities in Roman Britain
Roman Britain
Roman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...
. Britain was rich in resources such as copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
, iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
, lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
, salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
, silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
, and tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
, materials in high demand in the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
. The abundance of mineral resources in the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
was probably one of the reasons for the Roman conquest of Britain
Roman conquest of Britain
The Roman conquest of Britain was a gradual process, beginning effectively in AD 43 under Emperor Claudius, whose general Aulus Plautius served as first governor of Britannia. Great Britain had already frequently been the target of invasions, planned and actual, by forces of the Roman Republic and...
. They were able to use advanced technology to find, develop and extract valuable minerals on a scale unequaled until the Middle ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
.
Lead mining
Piping
Within industry, piping is a system of pipes used to convey fluids from one location to another. The engineering discipline of piping design studies the efficient transport of fluid....
for aqueducts and plumbing
Plumbing
Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping...
, pewter
Pewter
Pewter is a malleable metal alloy, traditionally 85–99% tin, with the remainder consisting of copper, antimony, bismuth and lead. Copper and antimony act as hardeners while lead is common in the lower grades of pewter, which have a bluish tint. It has a low melting point, around 170–230 °C ,...
, coffins, and gutters for villas
Villa
A villa was originally an ancient Roman upper-class country house. Since its origins in the Roman villa, the idea and function of a villa have evolved considerably. After the fall of the Roman Republic, villas became small farming compounds, which were increasingly fortified in Late Antiquity,...
, as well as a source of the silver that sometimes occurred in the same mineral deposits.
The largest Roman lead mines were located in or near the Rio Tinto (river) in southern Hispania
Hispania
Another theory holds that the name derives from Ezpanna, the Basque word for "border" or "edge", thus meaning the farthest area or place. Isidore of Sevilla considered Hispania derived from Hispalis....
.In Britannia the largest sources were at Mendip
Mendip
Mendip is a local government district of Somerset in England. The Mendip district covers a largely rural area of ranging from the Mendip Hills through on to the Somerset Levels. It has a population of approximately 110,000...
, South West England
South West England
South West England is one of the regions of England defined by the Government of the United Kingdom for statistical and other purposes. It is the largest such region in area, covering and comprising Bristol, Gloucestershire, Somerset, Dorset, Wiltshire, Devon, Cornwall and the Isles of Scilly. ...
and especially at Charterhouse
Charterhouse Roman Town
Charterhouse Roman Town was a town in the Roman province of Britannia. Its site is located just to the west of the village of Charterhouse-on-Mendip in the English county of Somerset....
. In 49 C.E., six years after the invasion and conquest of Britain, the Romans had the lead mines of Mendip and those of North West England
North West England
North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East...
and Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
running at full shift. By 70 C.E., Britain had surpassed Hispania
Hispania
Another theory holds that the name derives from Ezpanna, the Basque word for "border" or "edge", thus meaning the farthest area or place. Isidore of Sevilla considered Hispania derived from Hispalis....
as the leading lead-producing province
Province
A province is a territorial unit, almost always an administrative division, within a country or state.-Etymology:The English word "province" is attested since about 1330 and derives from the 13th-century Old French "province," which itself comes from the Latin word "provincia," which referred to...
. The Spanish soon lodged a complaint with Emperor Claudius, who in turn put limits on the amount of lead being produced in Britain. However, these limits were ignored and had the opposite effect on British lead production.
Silver extraction
The most important use of lead was the extraction of silver. Lead and silver were often found together, with the silver being encased in the lead oreOre
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
. The Roman economy was based on silver, as the majority of coins were minted from the precious metal.
The process of extraction, cupellation
Cupellation
Cupellation is a metallurgical process in which ores or alloyed metals are treated under high temperatures and carefully controlled operations in order to separate noble metals, like gold and silver, from base metals like lead, copper, zinc, arsenic, antimony or bismuth, that might be present in...
, was fairly simple. First, the ore was heated until the lead, which contained the silver, separated from the rock. The lead was removed, and heated up to 1100° Celsius
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
using hand bellows
Bellows
A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...
. At this point, the silver separated from the lead, and was put into molds which, when cooled, would form ingots that were to be sent all over the Roman Empire for minting.
Gold mining
Dolaucothi Gold Mines
The Dolaucothi Gold Mines , also known as the Ogofau Gold Mine, are Roman surface and deep mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales...
. The Romans discovered the Dolaucothi vein
Vein (geology)
In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...
soon after their invasion, and they used hydraulic mining
Hydraulic mining
Hydraulic mining, or hydraulicking, is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold.-Precursor - ground...
methods to prospect the hillsides before discovering rich veins of gold-bearing quartzite
Quartzite
Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...
. The remains of the several aqueducts and water tanks above the mine are still visible today. The tanks were used to hold water for hushing
Hushing
Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to...
during prospecting for veins, and it involved releasing a wave of water to scour the ground and remove overburden, and expose the bedrock. If a vein was found, then it would be attacked using fire-setting
Fire-setting
Fire-setting is a method of mining used since prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with water...
, a method which involved building a fire against the rock. When the hot rock was quenched with water, it could be broken up easily, and the barren debris swept away using another wave of water. The technique produced numerous opencasts which are still visible in the hills above Pumsaint
Pumsaint
Pumsaint is a village in Carmarthenshire, Wales situated half way between Llanwrda and Lampeter on the A482 in the valley of the River Cothi. It forms part of the extensive estate of Dolaucothi which is owned by the National Trust....
or Luentinum
Luentinum
Luentinum was a fort and mining settlement in the Roman province of Britannia. It was associated with the Dolaucothi Gold Mines and its remains lie beneath the adjoining village of Pumsaint in the Welsh county of Carmarthenshire. It lay between similar forts at Llandovery and Bremia near Llanio,...
today. A fort, settlement and bath-house were set up nearby in the Cothi Valley. The methods were probably used elsewhere for lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
and tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
mining, and indeed, were used widely before explosives made them redundant. Hydraulic mining
Hydraulic mining
Hydraulic mining, or hydraulicking, is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold.-Precursor - ground...
is however, still used for the extraction of alluvial tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
.
Long drainage adit
Adit
An adit is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, and ventilated.-Construction:...
s were dug into one of the hills at Dolaucothi, after opencast mining methods were no longer effective. Once the ore was removed, it would be crushed by heavy hammers, probably automated by a water wheel
Water wheel
A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface...
until reduced to a fine dust. Then, the dust would be washed in a stream of water where the rocks and other debris would be removed, the gold dust and flakes collected, and smelted into ingots. The ingots would be sent all across the Roman world, where they would be minted or put into vaults.
Iron mining
There were many iron mines in Roman Britain. The index to the Ordnance Survey Map of Roman Britain lists 33 iron mines: 67% of these are in the WealdWeald
The Weald is the name given to an area in South East England situated between the parallel chalk escarpments of the North and the South Downs. It should be regarded as three separate parts: the sandstone "High Weald" in the centre; the clay "Low Weald" periphery; and the Greensand Ridge which...
and 15% in the Forest of Dean
Forest of Dean
The Forest of Dean is a geographical, historical and cultural region in the western part of the county of Gloucestershire, England. The forest is a roughly triangular plateau bounded by the River Wye to the west and north, the River Severn to the south, and the City of Gloucester to the east.The...
. Because iron ores were widespread and iron was relatively cheap, the location of iron mines was often determined by the availability of wood for smelting fuel, which Britain had in abundance. Great amounts of iron were needed to fuel the Roman war machine, and Britain was the perfect place to fill that need.
Many underground mines were constructed by the Romans. Once the raw ore was removed from the mine, it would be crushed, then washed. The less dense rock would wash away, leaving behind the iron oxide
Iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...
, which would then be smelted
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
using the bloomery
Bloomery
A bloomery is a type of furnace once widely used for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. A bloomery's product is a porous mass of iron and slag called a bloom. This mix of slag and iron in the bloom is termed sponge iron, which...
method. The iron was heated up to 1500°C using charcoal. The remaining slag
Slag
Slag is a partially vitreous by-product of smelting ore to separate the metal fraction from the unwanted fraction. It can usually be considered to be a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and metal atoms in the elemental form...
was removed and generally dumped.
After being smelted, the iron was sent to forges, where it was reheated, and formed into weapons or other useful items.
Working conditions
Leat
A leat is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond...
s as well as the machinery needed to dewater mines and to crush and separate the ore from barren rock. Reverse overshot water-wheel
Reverse overshot water-wheel
Frequently used in mines and probably elsewhere , the reverse overshot water wheel was a Roman innovation to help remove water from the lowest levels of underground workings. It is described by Vitruvius in his work De Architectura published circa 25 BC...
s were used to lift water, and sequences of such wheels have been found in the Spanish mines. A fragment of a wheel found at Dolaucothi shows they used similar methods in Britain.
The working conditions were poor, especially when using fire-setting
Fire-setting
Fire-setting is a method of mining used since prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with water...
, an ancient mining method used before explosives became common. It involved building a fire against a hard rock face, then quenching the hot rock with water, so that the thermal shock
Thermal shock
Thermal shock is the name given to cracking as a result of rapid temperature change. Glass and ceramic objects are particularly vulnerable to this form of failure, due to their low toughness, low thermal conductivity, and high thermal expansion coefficients...
cracked the rock and allowed the minerals to be extracted. The method is described by Diodorus Siculus
Diodorus Siculus
Diodorus Siculus was a Greek historian who flourished between 60 and 30 BC. According to Diodorus' own work, he was born at Agyrium in Sicily . With one exception, antiquity affords no further information about Diodorus' life and doings beyond what is to be found in his own work, Bibliotheca...
when he discussed the gold mines of Ancient Egypt
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
in the first century BC, and at a much later date by Georg Agricola
Georg Agricola
Georgius Agricola was a German scholar and scientist. Known as "the father of mineralogy", he was born at Glauchau in Saxony. His real name was Georg Pawer; Agricola is the Latinised version of his name, Pawer meaning "farmer"...
in his De Re Metallica
De re metallica
De re metallica is a book cataloguing the state of the art of mining, refining, and smelting metals, published in 1556. The author was Georg Bauer, whose pen name was the Latinized Georgius Agricola...
of the 16th century. Every attempt was made to ventilate the deep mines, by driving many long adit
Adit
An adit is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, and ventilated.-Construction:...
s for example, so as to ensure adequate air circulation. The same adits also served to drain the workings.
See also
- Dolaucothi
- Naturalis HistoriaNaturalis HistoriaThe Natural History is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny...
- Pliny the ElderPliny the ElderGaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
- Roman BritainRoman BritainRoman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...
- Roman engineeringRoman engineeringRomans are famous for their advanced engineering accomplishments, although some of their own inventions were improvements on older ideas, concepts and inventions. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology...
- Roman technologyRoman technologyRoman technology is the engineering practice which supported Roman civilization and made the expansion of Roman commerce and Roman military possible over nearly a thousand years....
- Roman metallurgyRoman metallurgyMetals and metal working had been known to the people of modern Italy since the Bronze Age. By 86 BC, Rome had already expanded to control an immense expanse of the Mediterranean...