Fire-setting is a method of

traditional mining Traditional mining, also known as old-school mining, is a mining method involving the use of simple manual tools, such as shovels, pickaxes, hammers, chisels and pans. It is done in both surface and underground environments. Until the early 1900s, ...

used most commonly from prehistoric times up to the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

. Fires were set against a rock face to heat the

stone In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...

, which was then doused with liquid, causing the stone to fracture by

thermal shock Thermal shock is a type of rapidly transient mechanical load. By definition, it is a mechanical load caused by a rapid change of temperature of a certain point. It can be also extended to the case of a thermal gradient, which makes different pa ...

. Some experiments have suggested that the water (or any other liquid) did not have a noticeable effect on the rock, but rather helped the miners' progress by quickly cooling down the area after the fire. This technique was best performed in opencast mines where the smoke and fumes could dissipate safely. The technique was very dangerous in underground workings without adequate ventilation. The method became largely redundant with the growth in use of explosives. Although fire-setting was frequently used before modern times, it has been used sporadically since then. In some regions of the world, notably

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

, fire-setting continued to be in use until the 19th and 20th centuries. It was used where rock was too hard to drill holes with steel borers for blasting or whenever it was economic because of cheapness of wood.

History

The oldest traces of this method in Europe were found in southern

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

(département of

Hérault Hérault (; oc, Erau, ) is a department of the region of Occitania, Southern France. Named after the Hérault River, its prefecture is Montpellier. It had a population of 1,175,623 in 2019.Copper Age. Numerous finds exist from the

Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second prin ...

, such as in the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

, in the former mining district of

Schwaz Schwaz () is a city in the Austrian state of Tyrol. It is the administrative center of the Schwaz district. Schwaz is located in the lower Inn valley. Location Schwaz lies in the middle of the Lower Inn Valley at the foot of the Kellerjoch a ...

- Brixlegg in

Tyrol Tyrol (; historically the Tyrole; de-AT, Tirol ; it, Tirolo) is a historical region in the Alps - in Northern Italy and western Austria. The area was historically the core of the County of Tyrol, part of the Holy Roman Empire, Austrian Emp ...

, or in the

Goleen Goleen () is a small rural village in County Cork on the south-western tip of Ireland. Farming, tourism and construction work are among the main occupations of the local people. Location Goleen is located towards the south-western end of the ...

area in Cork,O’Brien, W: The Bronze Age copper mines of the Goleen area, Co Cork. Proc. R. Irish. Acad. 103, 2003:13–59 to name a few. As for antique written sources, fire-setting is first described by Diodorus Siculus in his Bibliotheca historica written about 60 BC, about methods of mining used in ancient Egyptian gold mines. It is also mentioned in greater detail by

Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ' ...

in his

Naturalis Historia The ''Natural History'' ( la, Naturalis historia) is a work by Pliny the Elder. The largest single work to have survived from the Roman Empire to the modern day, the ''Natural History'' compiles information gleaned from other ancient authors. ...

, published in the first century AD. In Book XXXIII, he describes mining methods for

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

, and the pursuit of the gold-bearing veins underground using tunnels and stopes. He mentions the use of

vinegar Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to eth ...

to quench the hot rock, but water would have been just as effective, as vinegar was expensive at the time for regular use in a mine. The reference to vinegar may come from a description by

Livy Titus Livius (; 59 BC – AD 17), known in English as Livy ( ), was a Roman historian. He wrote a monumental history of Rome and the Roman people, titled , covering the period from the earliest legends of Rome before the traditional founding in ...

of Hannibal's crossing of the

, when it was said that the soldiers used vinegar in fire-setting to remove large rocks in the path of his army. The effectiveness of strong acetic acid solutions on heated limestone has been demonstrated in laboratory experiments. Pliny also says that the method was used both in opencast and deep mining. This is confirmed by remains found at the Roman

gold mine Gold Mine may refer to: * Gold Mine (board game) *Gold Mine (Long Beach), an arena *"Gold Mine", a song by Joyner Lucas from the 2020 album ''ADHD Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characteri ...

Dolaucothi The Dolaucothi Gold Mines (; cy, Mwynfeydd Aur Dolaucothi) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mi ...

in west

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...

, when modern miners broke into much older workings during the 1930s where they found wood ashes near worked rock faces. In another part of the mine, there are three

adit An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adit ...

s at different heights which have been driven through barren rock to the gold-bearing veins for some considerable distance, and they would have provided drainage as well as ventilation to remove the smoke and hot gases during a fire-setting operation. They were certainly much larger in section than was normal for access galleries, and the draught of air through them would have been considerable. Fire-setting was used extensively during opencast mining, and is also described by Pliny in connection with the use of another mining technique known as

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 ...

Aqueducts Aqueduct may refer to: Structures *Aqueduct (bridge), a bridge to convey water over an obstacle, such as a ravine or valley *Navigable aqueduct, or water bridge, a structure to carry navigable waterway canals over other rivers, valleys, railw ...

were built to supply copious amounts of water to the minehead, where they were used to fill tanks and cisterns. The water was unleashed to scour the hillside below, both soil in the case of prospecting for metal veins, and then rock debris after a vein had been found. Fire-setting was used to break up the hard rocks of the vein and the surrounding barren rock, and was much safer to use in above ground workings since the smoke and fumes could dissipate more easily than in a confined space underground. Pliny also describes undermining methods that were used to facilitate the removal of hard rocks, and probably softer alluvial deposits as well.

Medieval Europe

Medieval silver mine gallery fire-setting Germany southern Black Forest 12th century

The method continued in use in the medieval period, and is described by

Georg Agricola Georgius Agricola (; born Georg Pawer or Georg Bauer; 24 March 1494 – 21 November 1555) was a German Humanist scholar, mineralogist and metallurgist. Born in the small town of Glauchau, in the Electorate of Saxony of the Holy Roman Emp ...

in his treatise on mining and mineral extraction, De re metallica. He warns about the problem of the "foetid vapours" and the need to evacuate the workings while the fires are lit, and presumably for some time afterwards until the gases and smoke had cleared. The problem raises the question of ventilation means in the mines, a problem often solved by ensuring that there was a continuous path for escape of the noxious fumes, perhaps aided by artificial ventilation. Agricola mentions the use of large water-powered

bellows A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtig ...

to create a draught, and continuity of workings to the surface were essential for a stream of air to run through them. In later times, a fire at the base of a shaft was used to create an updraught, but just like fire-setting, it was a hazardous and dangerous procedure, especially in

collieries Coal mining is the process of resource extraction, extracting coal from the ground. Coal is valued for its Energy value of coal, energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use c ...

. As the number and complexity of the underground workings increased, care was needed to channel the air draught to all parts of the tunnels and faces. It was usually achieved by installing doors at key points. Most of the deaths in coal mine disasters were caused by inhalation of the toxic gases produced by

firedamp Firedamp is any flammable gas found in coal mines, typically coalbed methane. It is particularly found in areas where the coal is bituminous. The gas accumulates in pockets in the coal and adjacent strata and when they are penetrated the releas ...

explosions. The method continued in use for many years afterwards until finally made redundant by the use of explosives. However, they also produce toxic gases and care is needed to ensure good ventilation to remove those gases, like

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

, as well as choice of the explosive itself to minimise their emission.

References

External links

Fire-setting at Alderley edge copper mines
(broken_link)
Fire-setting in ancient Indian mines
(broken_link) * * {{DEFAULTSORT:Fire-Setting Traditional mining History of mining

History

Medieval Europe

See also

References

Further reading

External links