Posts tagged Mahavansa

On manufacturing iron, ancient Balangoda history.

According to the local frictions there is evidence to say that, there was a high-tech, industry in manufacturing metal. Not only that, there is true evidence to support the above fact. One of them, among the various stones, there is a variety of stones called in the name of slag which is known among the locals of the country. They are called “ yabora in Sinhala”,.It means the rubbish / leftovers of iron, after manufacturing. The above mentioned stones are a common sight in the Balangoda area. In the recent past there has been consistent ; experiments, done by various peoples, and through that they have revealed that, sri Lanka has been manufacturing iron, using high – tech methods. Mrs. Gill Juleff, a researcher university of Exter revealed that the Sri lankans in the past have been manufacturing high – quality, and clean Iron, using local but high – tech methods. She also said that, the Sri Lankans have used the wind directions, and mountain – peaks to perfection, in order to get a good out cones. She also said that these methods can be applied even today for manufacturing iron in now a days. As the Mahavansa, Thoopawansa the poojawaliya, and various stone – plates readings reveal that Sri Lankans used various metals like, gold, silver, copper, led and iron. According to the archaeological , discoveries in Aligala, Sigiriya, people in Sri Lanka have been using, iron after manufacturing since the 9 th century A.D. By doing excavating researches in Balangoda Kumbalgama area, many significant informations in manufacturing iron in Sri Lanka has been discovered. It is sometimes said that the countryside that lies between the road running through Belihuloya and the Kaltota escarpment has `developed’ with the coming of the Samanalawewa Hydro-Electric Scheme. Discoveries made by the Samanalawewa Archaeological Project’ have however shown that, far from being a rural backwater, this area was, in the first millennium AD, the seat of technological innovations unparalleled in the ancient world. In brief, the invention of a unique wind-powered iron smelting furnace capable of producing high-quality steel sustained a large-scale industry that supplied the Islamic world with steel for sword-making. The dramatic findings of this project, described in more detail below, were recently presented to an international audience of archaeological-metallurgists at the British Museum in London with the result that Samanalawewa and Sri Lanka is now at the forefront of research in early steel-making. A temporary camp was established in the jungle close to the Kinchigune temple. From here, daily reconnaissance trips of up to 15 km were made on foot. Local villagers guided the survey team along -unmarked footpaths and contributed valuable local knowledge of place names, oral traditions and likely informants on aspects of iron-working practices. In the case of the west-facing sites the slag are elongated and sub-rectangular in form, and appear to have solidified against a straight wall or barrier. The furnace design indicated by these slag was unlike any previously recorded. A large site , located on the edge of the proposed reservoir, was selected and in 1990 a six-month excavation program was initiated. The site covered some 3000 m 2 and comprised a smelting area on the western brow of the ridge and deposits of slag extending downslope from the smelting area. Excavations concentrated on the smelting area and investigated approximately 20% of the site volume. The aims of the excavation were to examine and record the spatial layout of the site and any furnace structures which could be identified, and to resolve the stratigraphic sequence, and thus the chronology, of the site. Forty-one furnaces were revealed by excavation, all critically positioned on the western brow of the ridge and forming a near-continuous north-south line. The furnaces conform to a basic two-component design comprising a semi-permanent rear wall, terraced into the hillside or the accumulated debris of earlier smelting, aligned north-south and curving westwards at either end to form an elongated, open-fronted `stall’, and a temporary, single-smelt, straight wall across the (western) front of the `stall’ . This front wall is constructed on a foundation of re-used tapering tuyeres (clay pipes) which are telescoped one into another and laid horizontally to form a line. A series of eight charcoal samples collected during excavation have been dated by the radiocarbon and place the use of the site between the 7th and early 11 centuries AD. Excavations carried out at another site within the Samanalawewa survey area revealed a similar but smaller smelting furnace, which has been dated by radiocarbon to the 3rd century BC. In July 1994 a series of five practical trials were undertaken in an attempt to recreate the smelting process in the west-facing furnaces. In preparation for this a tonne of charcoal was produced by local blacksmiths, using traditional techniques, from tree species known to have been preferentially exploited for charcoal fuel from the 3 rd century BC up to this century. In the words of a local blacksmith. The jungle may be full of trees, but only a few of them make good charcoal. Charcoal samples collected during excavations have been identified by analysis as being predominantly of three species; marang (Syzgium Zeylanicum), path beriya (Syzygium spathulatum) and damba (Syzygium gardner) . Also in preparation, iron ore was collected from three different local deposits. The ore was then broken-up by hammering to an approximate 3 cm size. Material which was both light in weight and colour was discarded at this stage and only the heaviest material was retained for smelting. Analysis of the ore shows it to have a variable iron-oxide content of anything between 79% and 87%. This represents a high-grade ore, very suitable for smelting. A local potter was contracted to supply pre-fired clay tuyeres similar in shape and size to those found on the archaeological sites. The clay used for furnace construction was a locally recommended mixture of paddy-field and termite-hill clay with river sand and coarse gravel, charred and uncharred paddy husk and chopped paddy straw. A layer of charcoal was then added and the fire lit. Once the fire was established more charcoal was added until the furnace was full to the rim. The furnace was maintained in this way, with charcoal only, for two hours. This both heated the structure of the furnace and created a deep bed of burning charcoal.Smelting begins with the addition of the first of four pre-weighed ore/ charcoal `charges’ to the top of the furnace. These were added by first spreading the ore on top of the burning charcoal and then adding charcoal in stages as the material in the furnace burned down. After a further hour or so, the level within the furnace had burnt down to half the furnace height and at this point the furnace was opened by pushing the front wall inwards using long wooden poles.All three trials produced metal in increasing amounts. About 100 kg of ore had been charged into the furnace and final metal products were 2.0, 8.7 and 17 kg for the three trials respectively. This percentage yield is considered good for early iron smelting. with considerable amounts of slag, expected of pre-modem bloomery smelting, the Ancient Iron and Steel Production at Samanalawewa remaining material is relatively slag-free, homogeneous high-quality, high-carbon steel. In fact, so efficient is the furnace that the process of smelting and carbonization to steel is faster than any other recorded for pre-modern furnaces. The wind blowing over the furnace creates a `bubble’ on top of the furnace that seals it, trapping inside the vital hot, reducing gases. Although it is not unusual to find areas of high-carbon steel within the more customary low-carbon iron produced in bloomer furnaces, its unpredictable occurrence makes it a product not generally sought-after. It is hardly a surprise to find it capable, even in amateur hands, of producing high-carbon steel. This `furnace steel’ is comparable in quality to the crucible steels, produced in India and Sri Lanka from the 11 century AD onwards, which became famous as the material from which Islamic (Damascus) swords, were manufactured. From the writings of al-Kindi (Allan 1979) in the9th century AD we know that Sarandibi steel was much prized at the time for sword-making in the Islamic world. Al-Kindi does not specify whether, or not, Sarandibi steel was manufactured in crucibles, and the evidence from Samanalawewa now raises the possibility that `furnace steel’ may have reached the Arab world, via Indian Ocean trade routes, at a time before India gained ascendancy in the refining and Dr Gill Juleff is an Archaeologist who worked with the Samanalawewa Archaeological Project. She can be contacted at Pixton Park House, Dulverton, Somerset, TA 229 HW, England. The Samanalawewa Archaeological Project was run through the Archaeological Department of Sri Lanka and was funded by ODA (the British Overseas Development Administration), the British Council, the British High Commission in Colombo, the Society for South Asian Studies (British Academy) and by agencies involved in the Samanalawewa Hydro-Electric Scheme; Balfour Beatty and Sir Alexander Gibb and Partners. Valuable assistance at Samanalawewa was also provided by CEB (Ceylon Electricity Board), KHK and by the then Sabaragamuwa Affiliated University College.

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