Hushing
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Hushing is an ancient and historic
Hushing was used during the formation and expansion of the Roman Empire from the 1st century BC on to the end of the empire. It was also widely used later, and apparently survived until modern times where the cost of explosives was prohibitive. It was widely used in the United States, where it was known as "booming".
A variant known as
History
The method is well described by
Method
The power behind a large release of water is very great, especially if it forms a single
If veins of ore were found using the method, then hushing could also remove the rock debris created when attacking the veins. Pliny also describes the way hillsides could be undermined, and then collapsed to release the ore-bearing material. The Romans developed the method into a sophisticated way of extracting large
There are the remains of numerous tanks and reservoirs still to be seen at the site, one example being shown at right. It was a small tank built for prospection on the north side of the isolated opencast north of the main mine. It was presumably built to prospect the ground to one side of the opencast for traces of the gold-bearing veins extending to the north. It failed to find the veins here, so was abandoned. It probably precedes the construction of the 7 mile long aqueduct supplying the main site, and was fed by a small leat from a tributary of the river Cothi about a mile further north up the valley. The method could be applied to any ore type, and succeeded best in hilly terrain. The Romans were well experienced in building the long aqueducts needed to supply the large volumes of water needed by the method, and construction was probably directed by army engineers.
Earlier evidence
The earlier history of the method is obscure, although there is an intriguing reference by
The country of the Salassi has gold mines also, which in former times, when the Salassi were powerful, they kept possession of, just as they were also masters of the passes. The Durias River was of the greatest aid to them in their mining — I mean in washing the gold; and therefore, in making the water branch off to numerous places, they used to empty the common bed completely. But although this was helpful to the Salassi in their hunt for the gold, it distressed the people who farmed the plains below them, because their country was deprived of irrigation; for, since its bed was on favourable ground higher up, the river could give the country water. And for this reason both tribes were continually at war with each other. But after the Romans got the mastery, the Salassi were thrown out of their gold-works and country too; however, since they still held possession of the mountains, they sold water to the publicans who had contracted to work the gold mines; but on account of the greediness of the publicans. Salassi were always in disagreement with them too.[citation needed]
The historian
Later examples
The technique appears to have been neglected through the medieval period, because
The remnants of hush gullies are visible at many places in the Pennines and at other locations such as the extensive lead mines at Cwmystwyth in Ceredigion, Wales, and at the Stiperstones in Shropshire. Another notable example is the Great Dun Fell hush gully near Cross Fell, Cumbria, probably formed in the Georgian era in the search for lead and silver. This gully is about 100 feet deep, carries a small stream, and is a prominent landmark on the bleak moors. The dams used to store the water are also often visible at the head of the stream.
Although the term "hushing" was not used in south-west England,
In south-eastern Lancashire hushing was used to extract limestone from the glacial boulder clay so that it could be used to make lime for agriculture, mortar, plaster and limewash. Bennett notes leases of land for this purpose in the 17th and 18th centuries[5] and remains can still be seen at sites like Shedden Clough. Hushing for limestone seems to have been limited to the eastern side of the Pennine ridge, between Burnley and the Cliviger Gorge, and probably occurred here because of the cost of obtaining supplies from further away, as well as the suitability of the boulder clay and the availability of water supplies.
The technique was also used during alluvial gold mining in Africa, at least until the 1930s, when it was described by Griffith in his book Alluvial Mining (2nd Ed., 1960). The water outlet could be controlled by an automatic system which allowed water to flow through the sluice gate when the overflow triggered a release mechanism.
See also
- Dartmoor tin-mining
- Derbyshire lead mining history
- Dolaucothi Gold Mines
- Mining in Cornwall
- Placer mining
- Roman engineering
- Roman technology
- Roman mining
Notes
- ^ "Methods used". Lead Mining. Durham Miner Project. Archived from the original on 25 October 2008. Retrieved 24 April 2008.
- ^ "Glossary". Archived from the original on 25 October 2008. Retrieved 24 April 2008.
- ^ ISBN 978-1-84802-033-7.
- ^ "Archaeology Alive, volume 11" (PDF). The Historic Environment Service, Cornwall County Council. p. 37. Retrieved 24 April 2008.[permanent dead link]
- ^ Bennett, W. (1948) A History of Burnley Vol.2 p. 97.
References
- Oliver Davies, Roman Mines in Europe, Clarendon Press (Oxford), 1935.
- Jones G. D. B., I. J. Blakey, and E. C. F. MacPherson, Dolaucothi: the Roman aqueduct, Bulletin of the Board of Celtic Studies 19 (1960): 71-84 and plates III-V.
- Lewis, P. R. and G. D. B. Jones, The Dolaucothi gold mines, I: the surface evidence, The Antiquaries Journal, 49, no. 2 (1969): 244-72.
- Lewis, P. R. and G. D. B. Jones, Roman gold-mining in north-west Spain, Journal of Roman Studies 60 (1970): 169-85.
- Lewis, P. R., The Ogofau Roman gold mines at Dolaucothi, The National Trust Year Book 1976-77 (1977).
- Annels, A and Burnham, BC, The Dolaucothi Gold Mines, University of Wales, Cardiff, 3rd Ed (1995).
- Hodge, A.T. (2001). Roman Aqueducts & Water Supply, 2nd ed. London: Duckworth.
- Timberlake, S, Early leats and hushing remains: suggestions and disputes for roman mining and prospection for lead, Bulletin of the Peak District mines Historical Society, 15 (2004), 64 ff.
External links
- Royal Commission on Children in Mines describes hushing in 1842
- Roman technology
- Hushing in Yorkshire mines
- Great Dun Fell hush gulley
- Hushing in Gunnerdale, Yorkshire
- Roman gold mine with numerous aqueducts
- Hushing as used at Cwmystwyth mine
- Remains of hushing systems in Wales by Timberlake
- Shedings at Shedden Clough
- Shedden Clough Hushings