Part 4. Bharatiya metallurgical tradition
4.1 Yakshini, divinities of the hearth
A reference to itinerant metal-smiths who make arrows of metal, in the Rigveda (9.112.2) will have to be re-evaluated in the context of this evidence.
jarati_bhih os.adhi_bhih parn.ebhih s’akuna_na_m
ka_rma_ro as’mabhih dyubhih hiran.yavantam icchati_ (RV. 9.112.2)
This is a description of a smithy, perhaps an allusion to the making of copper reducing the ores. The metalsmiths sold the products (a copper implement or copper-tipped arrow or golden ornament) to moneyed-people.
a_la_kta_ ayomukham is.u (RV. 6.75.15): reference to poison and metal-tipped arrow.
r.s.t.i: a_sr.ukmaira_ yudha_ nara r.s.va_ r.s.t.i_h assr.aks.ata (RV. 5.52.6): javelin thunder spear
brahman.aspatireta_ sam. karma_ra iva_dhamat
deva_na_m. pu_rvye yuge asatah sadaja_yata (RV. 10.72.2): reference to metalsmith who blows in a furnace and makes metal objects.
kr.ti: has.tes.u kha_dis’ca kr.tis’ca (a guard and a sword)(RV. 1.168.3)
ks.ura: yada_ te va_to anuva_ti s’oirvapteva s’mas’ru vapasi prabhu_ma (RV. 10.142.4): With the wind at its back, fire wipes out the trees and forests and ‘shaves’ the land just as the barber shaves (with a razor).
khanitra: khanama_nah khanitraih (RV. 1.179.6): by the digging spade
kha_di: am.ses.u kha_dayo (RV. 7.56.13): shoulder decoration, sword?
paras’u: s’is’ite paras’um. sva_yasam. (RV. 10.53.): sharpened metallic axe.
pra_ca_ gavyantah pr.thupars’avo yayuh da_s.a_ ca vr.tra_ hatama_rya_ni ca (RV. 7.83.1): with big axes came to the east came the cow-plunderers — the da_sas as well as some a_ryas.
va_s’i_: va_s’i_ a_yasi_ (RV. 8.29.3): bronze tool-chisel, axe or adze. The neolithic one was as’manmayi_ va_s’i_ (RV. 10.101.10) made of stone.
svadhiti: ks.n.otren.eva svadhitim sam. s’is’i_tam (RV. 2.39.7): sharpen the swords/axes on the whetstone. means a sword?
Yakshini are bronze age divinities of the hearth. They are workers with fire, the crucible and the forge who could produce jewellery of immense beauty, as also thunderbolt vajra for Indra, metallic tools of immense utility and weapons. The running theme is the recurrent destruction and renewal of the cosmos, visarga and sarga, destruction and creation described by the metaphor of the cauldron of the smith or yaksha.
A cylinder seal of Gudea of Lagash (2143-2124 B.C.) read: "copper, tin, blocks of lapis lazuli– bright carnelian from the land of Meluhha." (Muhly, J.D., 1976, Copper and Tin, Hamden, Archon Books, pp. 306-7).
There could be an abiding association between metallurgy and kingship as evidenced by the word kavi which in Old Iranian means ‘poet, smith’ and a cognate word kayanides become the warriors and rulers of ancient Iran. Kavyava_hana in Rigveda is fire, the carrier of oblations offered in fire together with the metaphor of fire as the priest (agnim i_l.e purohitam), the carrier.
Many metaphors are unique to smiths of antiquity across civilizations, leading us to surmise that they were the same people of a maritime and riverine civilization of Indian Ocean rim with facility of movement on boats across long distances in search of minerals. Deformity of body seems to a characteristic of ancient smiths. Latin Volcanus was " bearded, sometimes with a slight facial deformity which doubtless recalled his infirmity,"and Volcanus’ anvil, hammer and tongs were imported from Greece. ( G.H. Luquet et al, New Larousse Encyclopedia of Mythology, Hamlyn, 1968). Greek Hephaestus, son of Zeus and Hera, was born with twisted legs and a dislocated hip, was thrown into the seas and picked up by two nymphs and would later fashion objects of gold and bronze, apart from building palaces for divinities on Mount Olympus. Hephaestus was helped in his various underground forges by Cyclopes who had one eye. Kensai (meaning ‘sword saints’) in Japanese folklore were farmer warriors.
Smiths were manufacturers of tools, and also weapons and hence responsible for supporting the soldiers carrying weapons to defend their communities. Tools made by smiths created a veritable revolution in civilizational history.
Who first engaged in alchemy, created the metals’ age, sought the veins of iron, learnt about the characteristics of minerals through experience, tempered the blades in oil 50 or 60 times and used many alloys of copper to make tools? Little people. Little people did work in the mines and smithies. Historical traditions across cultures associate dwarfs and elves with mining and smithy. Kubera and yaksha are the little people, the dwarfs who were involved in smithy, working with minerals, metals, alloys and furnaces, as demonstrated by the decipherment of Kubera’s navanidhi. An early center of iron manufacture seems to have been Ganga river basin, Illyria and Thrace. The little people are found as inspired, experimenting, itinerant explorers, naanaa des’eeya as many bharatiya epigraphs proclaim, they are like the gypsies. Maybe, they were the proto-gypsies.
Monbiot asks: ‘Why are the same myths associated with the blacksmiths all over the world?” ["Smith and the Devil" by George Monbiot, an essay published in Country Living Magazine] http://www.monbiot.com/dsp_article.cfm?article_id=59
Skanda Purana, describes a yaksa:“This mighty lion which was born from the anger of the Goddess will be your vehicle and he will be on your banner, O Goddess. Go to the Vindhya mountains and there do the work of the gods, killing Sumbha and Nisumbha, Taraka’s generals. This Yaksha, known as Pañcala, is given to you as your servant, endowed with hundreds of feats of magic illusion and attended by one hundred thousand Yaksas.” (Hindu Myths 1975:259).
KTM Hegde and Ericson, J.E., 1985, Ancient Indian Copper Smelting Furnaces, in: Furnaces and Smelting Technology in Antiquity, ed. P.T. Craddock, Occasional Paper No. 48, British Museum, London, pp. 59-67: The survey covered six ancient copper ore mining and smelting sites in the Aravalli (Arbuda) hills extending over a thousand kms.: Khetri and Kho Dariba in NE, Kankaria and Piplawas in the Central part and Ambaji in SW.. A large majority of mine-pits measure 7-8 metres in dia. and 3-4 metres deep showing evidence of fire-treating of the host rocks on the mine walls to widen rock joints. The evidene indicated probable mining in the chalcolithic period. Timber supports recovered from a gallery at a depth of 120 metres at Rajpura-Dariba mines in Udaipur District were radio-carbon dated to 3120+_ 160 years before the present (1987). This correlates with the zinc-containing copper artefacts of Atran~jikhera. Finely crushed ore was concentrated by gravity separation at the smelting sites which were invariably close to the banks of hill streams. This helped separate gangue from the ore. Smelting charge was by crushed quartz equal to the weight of the ore, crushed charcoal twice the weight of the ore. Furnace walls showed evidence of residues of small, hand-made, fistfuls of spherical lumps. The smelter furnace was a small, crucible-shaped, clay-walled, slag-tapping deice worked on forced draught from bellows; ‘this simple furnace appears to have been continuously used in India over the millennia without little innovation.’ It would appear that the facilities in the metropolis of the civilization on the banks of Sarasvati and Sindhu were only purification and fabrication facilities with limited or no smelting operations. Bun-shaped copper ingots from Ganeshwar taken through the riverine routes were perhaps carried by itinerant metal-smiths of the copper-hoard culture and fabricated in cities like Mohenjodaro and Harappa to meet the specifications of the consumers of this doab or the Tigris-Euphrates doab.
"Detail of the iron pillar at Delhi. Its rust-free surface is evidence of the superior quality of traditional technology. Iron beams used in the temples of Konark and Puni in coastal Orissa are further examples of the rust free nature of traditional Indian iron."
"The amazing metal mirror of Aranmula. Its highly polished and reflective surface acts as a high quality and distortion free mirror that equals any of today’s glass mirrors."
Kautilya’s magnum opus, the Arthashastra, is regarded by many a scholar as the last word in sense and cunning. Here, we briefly focus on the former aspect! Written in the fourth century BC, the work discusses metals and minerals, the purification of their ores, the extraction and working of metals, as well as their alloys. On one hand, the book suggests the purification of ores by chemical treatment with iron or alkalis (i.e. plant ashes). On the other, it recommends the use of charcoal and chaff (waste products of food preparation) in limekiln and for smelting iron. Clearly, recycling mattered! In addition, there are pointers to the location of mineral deposits.
Varahamihira in the sixth century AD indicates the hardening of steel in his Khargalakshanam:: ” The red hot steel should be plunged into a solution of plantain ashes in whey, which is kept standing for twelve hours and then it should be sharpened on the lathe.”
Vrinda discussed the process of killing iron (i.e. obtaining iron oxides). He insists that iron first be ignited in fire and then immersed in the juices of Emblic myrobalan and Trewia nundiflora. Next, it should be exposed to sunlight, and then again macerated in certain other plant juices. Last, it should be placed in a mortar and rubbed.
The twelfth century Tantric text Rasarnava holds forth on the colour of flames, the processes of killing metals, and the test of a pure metal. The last – ”A pure metal is one which when melted in a crucible does not give off sparks nor bubbles, nor spurts, nor emits any sound, nor shows any lines on the surface but is tranquil like a gem.”
Another text Rasaratnasamuchchaya speaks of iron as one of the pure metals, and the three categories thereof:
(i) Mundam (wrought iron) is of three types – one is the mridu, that is glossy, will melt easily but is difficult to break; the second, kunthum, that does not melt easily; and the kadaram that will easily break under the hammer;
(ii) Tikshnam (cast iron steel) – of six types, ranging from the line-free and rough and breakable type to the sharp-edged type that is difficult to break.
(iii) Kantam is of five types – bhramaka (that can make iron move about), chumnbaka (that which ‘kisses’ iron), karshaka (that which attracts iron), dravaka (which melts iron easily), romakanta (which expels hair-like filaments upon breaking).
Zinc mining and smelting were known in the fourteenth century, and soldering was a common practice. By the eighteenth century, steel manufacture was a regular industry, particularly in Mysore. Seringapatnam was famous for its steel wires for musical instruments, while iron utensils and furniture were hallmarks of the smiths of Birbhum in the state of Bengal and Munger in the state of Bihar.
Pot furnace, Lothal. http://www.harappa.com/lothal/6.html
The introduction of antimony in addition to the tin and copper produces a harder bronze, better able to hold a cutting edge and less likely to be bent in use.
Antimony sulphide (Sb2S3) in the form of powder was used in the Orient as a cosmetic to darken and beautify their eyebrows. An alloy of lead, tin, antimony, and a little copper was the metal of choice for casting movable type for printing from the time of Gutenberg until modern printing techniques superseded "hot metal" a few years ago. The alloys of antimony include britannia metal, type metal, Babbitt metal, and sometimes pewter; these alloys expand on cooling, thereby retaining fine details of a mold. Alloys and compounds of antimony are used in bearings, storage batteries, safety matches, and as a red pigment in paint.
Lupus metallorum = The grey wolf or stibnite, used to purify gold, as the sulphur in the antimony sulphide bonds to the metals alloyed with the gold, and these form a slag which can be removed. The gold remains dissolved in the metallic antimony which can be boiled off to leave the purified gold. "kohl, antimony paste" [ultimately perhaps < akk. Guhlu, ‘alcohol’]
These samples of stibnite are on display at the Smithsonian Museum of Natural History. The size of the left sample is about 20-30 cm high. Stibnite is antimony sulfide, Sb2S3.
Antimony is a brittle metal, silvery gray in color. It has the property of expanding upon freezing, and its main application has been as a constituent of type metal (82% lead, 15% antimony, 3% tin). The expansion upon solidifying gives sharp reproduction of type characters in the molds. http://hyperphysics.phy-astr.gsu.edu/hbase/pertab/sb.html
Stibium or antimony sulphide was roasted in an iron pot to form antimony. Initial uses were as an alloy for lead as it increased hardness. Stibnite is the most common ore. It was commonly roasted to form the oxide and reduced by carbon. http://neon.mems.cmu.edu/cramb/Processing/history.html
Zinc. A Chinese text from 1637 stated the method of production was to heat a mixture of calamine (zinc oxide) and charcoal in an earthenware pot . The zinc was recovered as an incrustation on the inside of the pot. In 1781 zinc was added to liquid copper to make brass. This method of brass manufacture soon became dominant. http://neon.mems.cmu.edu/cramb/Processing/history.html
Excavation of Zinc Distillation Furnaces at Zawar, Abstracts Ð 1984, Symposium on Archaeometry, Smithsonian Institute, Washington D.C., 1984 (V.H. Sonawane, K.T.M. Hegde and P.T. Craddock).
The reduction of ZnO by charcoal requires a temperature of 1000 °C or more and, because the metal is a vapour at that temperature and is liable to reoxidation, its collection requires some form of condenser and the exclusion of air. This was apparently first achieved in India in the thirteenth century. The art then passed to China where zinc coins were used in the Ming Dynasty (1368-1644). Marco Polo described the manufacture of zinc oxide in Persia and how the Persians prepared tutia (a solution of zinc vitriol) for healing sore eyes (cf. the Georgian name for the metal). The presence of zinc in a Lothal arteact (2200-1500 B.C.) (No. 4189) assayed: 70.7 percent copper; 6.04 zinc; 0.9 Fe, 6.04 acid-soluble component (probably carbonate, a product of atmospheric corrosion). The zinc and other components could have come from the Ahar-Zawar area, Rajasthan. The next dated brass artefacts are: from the Gordian tomb in Phrygia of the eigth and seventury B.C. and Etruscan bronze of the fifth century B.C. containing 11 percent zinc.
References to Zinc and brass are found in the lost text Philippica or Theopompus (4th century BC), quoted in Strabo’s Geography (XIII, 56): "There is a stone near Andreida (north west Anatolia) which yields Iron when burnt. After being treated in a furnace with a certain earth it yields droplets of false silver. This added to copper, forms the so-called mixture, which some call oreichalkos." This pertains probably to the process of downward distillation of zinc ("droplets of false silver") and its subsequent mixing with Copper to make brass oreichalkos (arakuta in Kautilya’s Arthasastra) described in detail in the post-Christian era Sanskrit texts. The first slab zinc or spelter was imported from the East by the East-India companies around 1600, late when compared with Iron, Copper or Lead. In 1597, the German Andreas Libavius (1545-1616) received from a friend a "peculiar kind of tin" which was prepared in India. He called it Indian or Malabar lead. He was uncertain what it was, but from his account it is quite clear that that metal was Zinc. http://www.vanderkrogt.net/elements/elem/zn.html The metal did not even have a universally accepted name before the eighteenth century.
tutenag or tutanego, derived from the Persian tutiya, calamine [ZnCO3], which became the English tutty, zinc oxide. The Person word tutiya is derived from a word that means smoke. It refers to the fact that zinc oxide is evolved as white smoke when zinc ores are roasted with charcoal.
spelter (referring indiscriminately to Zinc and Bismuth), likely from the similar coloured lead-tin alloy, pewter, or the Dutch equivalent, spiauter or Indian tin. The British chemist Robert Boyle latinised this in 1690 to speltrum from which originates spelter, the commercial term for zinc.
The term zink was first used by by Paracelsus (c. 1526) in analogy of the form of its crystals after smelting. The word was subsequently used for both the metal and its ores.
The word zink is derived from the High German zink of zinke = sharp point (from Old High German zint "a point, jag," from Proto-Germanic *tindja "tine"), the shape in which the metal deposits in the melting furnace. Some suppose a relation with Zinn, the German word for Tin. Georgian თუთია [t'ut'ia]: After the Persian tutia, a solution of zinc vitriol.
Natron is potassium nitrate or saltpetre or barud. In Al-Madkhal al-ta`limi (Instructive Introduction) and in Kitab al-Asrar (The Book of Secrets), Abu Bakr Muhammad Ibn Zakariyya al-Razi (Rhazes) (d. 925 AD) mentions that Goldsmiths’ Borax is white and is similar to al-sabkha (al-shiha) which is found at the feet of walls. The same description appears in the Karshuni manuscript (written in Arabic with Syriac script), which belongs to the period ninth to eleventh century according to Berthelot and Duval. Duval translated al-shiha which is found at the feet of walls as saltpeter.  Karshuni manuscript that use the word barud. Here are two: “ Item 174 – For a violent fusion – two parts pure alum; 2 burnt copper, two barud ; one black [vitriol]; two tutiya ; one honey; let the work be done in an enamelled glass ware (zujaja khazafiyya), [one adds] raisins and one [olive] oil; and begin work. This word occurred as al-sabkha and as al-shiha in the various texts.  Al-Razi, Abu Bakr Muhammad b. Zakariyya b. Yahya, Kitab al-Asrar wa Sirr al Asrar, ed. Muhammad Taqi Danishpazhuh, Tehran, 1343(1964), p. 6  Berthelot, M.and R. Duval, La Chimie au Moyen Age, vol. II, Paris, 1893. p. XII. The Karshuni MS was published in Syriac script, with a translation into French by Duval. The Karshuni Arabic text was converted into Arabic script in Aleppo by the Rev. Father Bar§um on the request of the author of the present paper. The Arabic text in Arabic script is still in MS form.  Berthelot and Duval, 1893, p. 145  The word barud came in the Arabic text, but Duval translated barud into natron, [Berthelot and Duval, op. cit.,p. 187], which means sodium carbonate in modern European languages. This is a gross error with no explanation.  The word vitriol was added in Duval’s translation, p. 187. Words between square brackets are added by Duval to the French translation.  translated as antimony by Duval.  Translated as soot (suie) by Duval.
"In the ancient Near East… when working gold by streaming, nodules of cassiterite (or tin-stone SnO2) were found. This cassiterite was reduced by workers already proficient in the production of gold, silver and lead. The metal obtained was held to be a kind of lead. [In Sanskrit, the term for lead is: na_ga. In Akkadian, the term for tin is: anakku). Lead and antimony were already used to increase the ease with which copper could be cast, but neither of them improved in its other qualities, notably the tensile strength. From trials with the new kind of ‘lead’, it would be learnt that this mixture was now improved in tensile strength as well as in ease of casting. Nor was it necessary to produce this new metal first; unrefined copper had only to be smelted with charcoal and stream-tin to produce a new kind of ‘copper’ (ayas in Rigveda), namely bronze, with superior qualities for tools and weapons. At the same time, certain naturally mixed ores were also worked, and were found to give the better kind of ‘copper’ directly. We have no proof that the tin compound of these mixed ores was ever isolated or recognized. Furthermore, at this early stage the tin content of the bronze could not be adequately controlled, and therefore varied between fairly wide limits." (Adapted from: R.J.Forbes, 1954, Extracting, smelting and alloying, in: Charles Singer, E.J.Holmyard and AR Hall (eds.), 1954, A History of Technology, Oxford, Clarendon Press).
During the second millennium it is clear that an amalgamation process using molten lead was used to separate the metal from crushed electrum quartz. Later, Stibium (antimony sulfide) was also used in the cementation process. http://neon.mems.cmu.edu/cramb/Processing/history.html
Like antimony, arsenic added to the tin and copper (up to as much as 3% of the whole) produces a harder final product. Arsenic fairly routinely occurs as an impurity in early bronze anyway, and small amounts of it were probably not intentional or particularly noticeable in the final product. By the time the proportion of arsenic in bronze reaches two or three percent, however, the effects are quite noticeable and presumably intentional. It is to these products that the term "arsenical bronze" is usually applied.
Mixing lead into the copper-tin alloy produces "lead bronze," which may contain as much as 10% lead. The lead in the alloy does not become part of its crystalline structure, increasing the fluidity of compound when it is in its molten state. This facilitates casting, particularly the casting of finely detailed artistic objects. However lead bronze is softer than normal bronze, and therefore less able to hold a cutting edge, making it less appropriate for many types of tools.
Increasing the amount of tin in the alloy much about 10% produces greater brittleness, and tools made that way easily break. However alloys with more tin —potin (up to 20% tin) and speculum (more than 30% tin)— were used for early coins in some parts of Europe, where bittleness was not a significant problem.
The term "Bronze Age" refers to those periods around the world in which bronze was in general use. The specific dates of course vary from region to region, and vary also with the rigidity with which one defines "general use." The Bronze Age in any given place is considered to have come to an end when the generalization of iron brought on the beginning of the Iron Age, an equally problematic term.
Brass is an alloy of copper with zinc, and is usually made up of anywhere from ten to forty percent zinc. Small amounts of other ores produce special-purpose brass. (Tin and aluminum increase resistance to corrosion, for example.) Zinc ore (called calamine) is difficult to mix with the copper ore, however, and brass appears later in the archaeological record as well as being far less common than bronze.
“The earliest firm evidence for the production of metallic zinc is from India. Of the metals used in antiquity zinc is one of the most difficult to smelt since zinc volatalises at about the same temperature of around 1000oC that is needed to smelt zinc ore. As a result it would form as a vapour in the furnace which would immediately get reoxidised and hence lost. Hence metallic zinc is seldom reported in antiquity. However in India there is unique evidence for the extensive and semi-industrial production of metallic zinc at the Zawar area of Rajasthan. An ingenious method was devised of downward distillation of the zinc vapour formed after smelting zinc ore using specifically designed retorts with condensers and furnaces, so that the smelted zinc vapour could be drastically cooled down to get a melt that could solidify to zinc metal. The Rasaratnakara, a text ascribed to the great Indian scientist Nagarjuna, of the early Christian era describes this method of production of zinc.” http://www.tf.uni-kiel.de/matwis/amat/def_en/articles/metallurg_heritage_india/metallurgical_heritage_india.html