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Iron in Ancient India c9: Chapter VI. Indian Steel or Wootz

Iron in Ancient India c9

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Chapter VI. Indian Steel or Wootz

Derivation of "Wootz"

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The word "wootz," by which name Indian steel was and is still known in Europe, is a curious word meaning steel made in Southern India. The name seems to have originated in some clerical error or misreading very possibly for "wook" representing the Canarese word "ukku" meaning steel, and first appears in a paper read by George Pearson, M.D., before the Royal Society of England in June 11, 1795, and entitled "experiments and observations to investigate the nature of a kind of steel manufactured at Bombay and there called wootz."¹ Mr. J. M. Heath is evidently wrong in thinking "wootz" to be the name for steel in the Guzerattee language in use at Bombay. Dr. Edward Balfour suggested that the word "wootz" perhaps was "uchcha," meaning "of superior quality," in the Canarese language, as distinguished from "nicha" or "of inferior quality." This suggestion does not appear to be satisfactory at all.

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¹ Hobson-Jobson, "Glossary," p. 972.

Historical

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Wootz seems to have been prepared from time immemorial in the Nizam's Dominions, Mysore and Salem, and other parts of the Madras Presidency and was the metal from which the famous Damascus blades were prepared. The presence of numerous Asoka pillars of stone cut out in a faultless manner from single pieces of stone of gigantic dimensions presupposes the use of the finest steel saws and steel chisels in India in the fourth century B.C. The use of a large number of surgical instruments in the Sushruta (third century B.C.), some of which "could bisect a hair longitudinally," also points out to the use of steel in India in making cutlery and surgical instruments in pre-Christian times. Moreover " we can hardly doubt that the tools with which the Egyptians covered their obelisks and temples of porphyry and syenite with hieroglyphics were made of Indian steel. There is no evidence to show that any of the nations of antiquity besides the Hindus were acquainted with the art of making steel. The notices which occur in the Greek and Latin writers on this subject serve only to betray their ignorance of it; they were acquainted with the qualities and familiar with the use of steel, but they appear to have been altogether ignorant of the mode in which it was prepared from iron. The arms and cutting instruments of the ancients were all formed of alloys of copper and tin, and we are certain that tools of such an alloy could not have been employed in sculpturing porphyry and syenite

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........ One certain fact has reached us regarding the antiquity of the steel manufacture in India: Quintus Curtius mentions that a present of steel was made to Alexander of Macedon by Porus, an Indian Chief, whose country he had invaded. We can hardly believe that a matter of about thirty pounds' weight of steel would have been considered a present worthy of the acceptance of the conqueror of the world, had the manufacture of that substance been practised by any of the nations of the West in the days of Alexander....... We know that a maritime intercourse was maintained from the remotest antiquity between the Malabar Coast, the Persian Gulf, the country about the mouths of the Indus and the Red Sea; and it appears reasonable to conclude that the steel of the south of India found its way by these routes to the country of Porus, to the nations of Europe and to Egypt."¹

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¹ J. M. Heath, Journal Royal Asiatic Society, 1839, Vol. V, 395.

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Abundant evidence is forthcoming to testify to the fact that India supplied the iron for the famous Damascus blades. Sir George Birdwood says, " Indian steel was celebrated from the earliest antiquity, and the blades of Damascus which maintained their pre-eminence even after the blades of Toledo became celebrated, were in fact of Indian iron. Ctasias mentions two wonderful Indian blades which were presented to him by the King of Persia and his mother. The Ondanique of Marco Polo's travels refers originally, as Col. Yule has shown, to Indian steel, the word being a corruption of the Persian Hundwaniy, i.e. Indian steel: The same word found its way into Spanish in the shape of "Al-hinde" and "Al-finde" first with the meaning of steel and then of a steel mirror and finally of the metal foil of a glass mirror. The Ondanique of Kirman, which Marco Polo mentions, was so called from its comparative excellence, and the swords of Kirman were eagerly sought after in the fifteenth and sixteenth centuries A.D. by the Turks who gave great prices for them. Arrian mentions steel as imported into the Abyssinian ports, and Salmasius mentions that among the surviving Greek treatises was one on the tempering of Indian steel.¹ The celebrated traveller Tavernier writing about Indian iron of his time said, "The steel susceptible of being damasked comes from the Kingdom of Golconda; it is met with in commerce in lumps about the size of a half-penny cake; they are cut in two, in order to see whether they are of good quality, and each makes half the blade of a sabre." Even in the early part of the nineteenth century the trade in steel with Persia was quite profitable. Dr. Voysey in his article on the "Description of the Native Manufacture of Steel in Southern India"² writes: "The export, however, of the metal to Persia must be profitable, as it is sufficient to bring dealers from that country and to defray the cost and risk of travelling. We found at the village (named 'Kona Samundram,' 12 miles south of the Godaveri and 25 miles from Nirmul, celebrated for its manufacture of steel), in 1820, Haji Hosyn, from Ispahan, engaged in the speculation; and it must have answered his purpose, as he was here again in 1823, having returned in the interval to Persia and disposed of the venture. He informed us that the place and the process are both familiar to the Persians and that they have attempted to imitate the latter without success." Syed Hussain Bilgrami³ writes, "From time immemorial the iron of the Nizam's territories has been worked at Yalgharab, Nirmul, Juctial, Warangal and other places into blooms from which cast steel of a very superior quality was manufactured and exported to the far West. It has been proved that the raw material from which the famous Damascus blade was manufactured, was obtained from an obscure village in the Nizam's territory" (meaning perhaps the village of Kona Samundram described above by Dr. Voysey). The geologist Ball holds the same opinion and writes in his "Geology of India" that "there are distinct evidences that wootz was exported to the West in very early times, possibly 2000 years ago."

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¹ Sir George Birdwood's "Hand-book to the British Indian Section of the Paris Exhibition of 1878."

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² An extract from the manuscript journals of Dr. Voysey printed in Journal Asiatic Society (of Bengal), Vol. I, 1832, p. 247.

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³ Syed Hossain Bilgrami on "Iron Industry in Hyderabad," Journal of the Iron and Steel Institute, 1899, No. 11, p. 75.

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It would interest readers to learn in what parts of India itself, which supplied the steel for making Damascus blades, swords were manufactured. We find a list of such places in *Yukti-kalpataru*, which has already been referred to as a manuscript of the eleventh century, which says that swords were manufactured in Benares, Magadha, Ceylon, Nepal, Anga, Mysore, Surat and Orissa (Kalinga) and describes the qualities of the swords manufactured in the various places.¹ We have found a similar reference in *Śārangadhar-Paddhati*, a work undoubtedly composed in the fourteenth century by the alchemist Śārangadhar. In it we find that in the fourteenth century the following places were noted for the manufacture of swords, viz. Khatikhattara, Rishi, Banga (Bengal), Shurporaka, Videha (Mithilā or Tirhut), Anga (Bhāgulpur), Madyamā-grām, Bedidesha, Sahagrām, and Kalinjar, and that swords manufactured in China were "faultless and pure."' In *Shārangadhar Padhati* as well as in *Yukti-kalpataru* long chapters on the dimensions and qualities of swords as well as on varieties of iron and their different colours have been inserted.

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¹ तद्यथा वाराणसीमगधसिंहलभूमिषु नेपालभूमिषु तथाङ्गमैसूरप्रदेशे । खोरराष्ट्रिक्यन्तरधन्यसद्‌विभागमे शुदावयां ज्ञातवरां प्रवदन्ति जम्बा तद् यथा ॥ वाराणसेयाः सुस्निग्धास्तिक्ष्णधाराः सद्विषाः । मगधजाः सुसम्भवेयाः क्षेयोचाभिद्यमासिनः । मागधाः कर्कशास्त्यक्तधारास्तरोत्तरिणः । गुरवो दुःसम्भवेयाः कङ्गाज्ञेया विचक्षसैः । नेपालदेशप्रभवाः निरङ्काः निषदाश्च ये । अङ्गाः सद्वशमलिनाः जम्बकः खड्गधारिणः । कलिङ्गाः गुरवः सच्छायताश्चानुसेतवाः । ओराङ्काः निर्गताः स्निग्धाः सुप्रभाश्चाष्टमङ्गराः । सिंहलद्वीपजातानां चतुर्भेद उच्यते । केचित् सदङ्गा गुरवः कर्कशास्त्यक्तधारिणः । केचित् सदलम्बवः सच्छिद्रभास्त्यक्तधारिणः । युक्तिकल्पतरु ।

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The Sanskrit equivalent for steel is *tikshna*. The word occurs in the *Arthasāstra* (p. 83) and in the *Sushruta* (see *ayaskriti*), but it is doubtful if the word meant any particular *kind* of iron in those ancient times. In the *Rasaratna-samucchaya* six varieties of *tikshna* iron are mentioned (see p. 45). In the *Bhāvaprakāsha* (sixteenth century) steel is called *shār-lauha*, and is described as a "kind of iron which when treated with acid becomes as sharp as the peak of a mountain."

Manufacture of Wootz—Crucible Process of Making Cast-Steel by Cementation

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We would now proceed to describe the traditional Indian method of manufacturing steel—"the ondanique of Marco Polo—which supplied many a true blade girded by Asiatic conquerors of yore, and may be said to have overthrown dynasties and established empires." It has already been said that Indian steel was in great demand in the Middle Ages not only in Asia but also in Europe, and many attempts at imitation were naturally made by Europeans though unsuccessfully. Mr. Henry Wilkinson informs us in this connection that "with respect to the various

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वङ्ग-कङ्क-रोधिक-वंग-भूपारकेषु च।
विदेहेषु तथाङ्गेषु मध्यमाम-वेदिषु।
मध्यमामेषु चीनेषु तथा कालञ्जरेषु च।
खड्गप्रधाने तज्ज्ञानं खड्गानां शृणु लक्षणं।
खड्गोऽहर्जाता ये दर्शनीयाश्च ते मताः।
काष्ठच्छिदः सार्धकार्ये सर्वशास्त्रविशारदाः।
तीक्ष्णाः वेदमयाः खड्गाः खड्गाः भूपारकोद्भवाः।
चमत्कृतैर्विज्ञेयाः प्रभावतः विदेहजाः।
खड्गेऽपि खड्गाः मध्यमाः मध्यमाः।
खड्गाश्चमत्कृताः वेदिदेशसमुद्भवाः।
सद्योऽमीखड्गाः सुतीक्ष्णाश्चमत्कृताः।
मित्रपाणिप्रशस्ताश्चीनेदेशसमुद्भवाः।
कालिङ्गराः कालमदातेषां वक्ष्यामि लक्षणं।
इत्युत् शार्ङ्गधरपद्धति, खड्गप्रशंसा।

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attempts at imitation, the least ingenious one is certainly that of etching or engraving a blade of common steel, more to deceive the purchaser. Amongst the numerous failures we may enumerate those of Messrs. Nicholson, O'Reilly, Wilde and others in England as well as that of Monsieur Clouet in France."¹

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¹ Journal Royal Asiatic Society, 1837, Vol. IV, p. 188.

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The first to examine wootz chemically was Dr. Pearson, who in 1795 contributed a paper on the subject to the Philosophical Transactions of the Royal Society (Part II). The difference between wrought iron and steel, as is well known, lies in the fact that steel contains more carbon than wrought iron while cast iron contains still more carbon than either wrought iron or steel. But owing to the imperfect methods of analysis prevalent at that time Dr. Pearson states the results of his analysis of the percentage of carbon in a curious fashion. He estimated "the quantity of carbon in the wootz and steel to be nearly equal; and that quantity to be about one-third of the hundredth part or 1/300 of the weight of these substances." He also estimated the specific gravity of wootz as follows:—

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| 1. | Wootz | .. | 7·181 |
| 2. | Another specimen of wootz | .. | 7·403 |
| 3. | The same forged | .. | 7·647 |
| 4. | Another specimen forged | .. | 7·503 |
| 5. | Wootz which had been melted | .. | 7·200 |
| 6. | Wootz which had been quenched while white hot.. | .. | 7·166 |

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Dr. Scott who forwarded the specimens of wootz to Dr. Pearson from Bombay described that wootz was used "for cutting iron on a lathe, for cutting stones, for chisels, for making files, for saws, and for every purpose where excessive hardness was necessary." Wootz, however, could not bear anything beyond a very slight red heat, which made it work very tediously in the hands of smiths. There is very little of chemical importance in Dr. Pearson's paper, and he was quite mistaken, as will be shown below, in thinking "we may without risk conclude that it (wootz) is made directly from the ore and consequently that it has never been in the state of wrought iron," the actual process being just the reverse, viz. carburisation of wrought iron. Faraday and Stoddart had also examined wootz.

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The first complete analysis of ‘wootz’ was made by Mr. T. H. Henry in the middle of the nineteenth century. The results of his analysis are given below:—

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| Carbon combined | .. | 1·333 | 1·340 |
| " uncombined | .. | ·312 | .. |
| Silicon | .. | ·045 | ·042 |
| Sulphur | .. | ·181 | ·170 |
| Arsenic | .. | ·037 | ·036 |
| Iron by difference | .. | 98·092 | |
| | | 100·000 | |

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Steel may be prepared in two ways, firstly, by removing part of the carbon of cast iron before it is converted into wrought iron; or secondly, by carburising wrought iron or making it combine with the requisite quantity of carbon. The second process is called the "process of cementation" and has been discovered in England only in the eighteenth century, while Indian iron was prepared by this process from time immemorial. As has already been mentioned, Sir Robert Hadfield on examining photomicrographically some ancient Ceylonese iron specimens of the fifth century A.D. found that a chisel showed distinct signs of carburisation varying on the two faces "from saturation point (·9 per cent) to about ·2 per cent carbon on the outside edge." He further remarks: "the presence of martensite and hardenite suggests the important information that the chisel has been quenched."¹ Sir Robert concludes: "the author believes this to be the first time there has been put up on record evidence of the art of cementation having been known 1500 to 2000 years ago, as shown by these specimens; probably therefore, such knowledge could be traced back still further." Ceylon, having been only a part of Greater India, we may safely conclude that the process of cementation and quenching was known in India "1500 to 2000 years ago," if not earlier.

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¹ Journal of Iron and Steel Institute, 1912, Vol. 85, No. 1, p. 164.

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Judging from the conservatism of the people we would expect to find the same process in working in the eighteenth or nineteenth century, though it must be confessed, on an infinitely smaller scale, as the scientific spirit of enquiry and industrial enterprise seem to have almost left India to find a new habitat in Europe at the close of the seventeenth century. We have, however, got excellent account of steel manufacture in Southern India from the accounts of travellers like Dr. Voysey (1795), Buchanan (1800) and Heyne (1794-1814). The process of Indian steel-making may be summarised in the following way—wrought iron is first obtained by the *direct method*, viz. heating the ores of iron with charcoal in small blast furnaces (the blast being admitted by means of hand bellows) without the intermediate formation of cast iron as has already been described. The wrought iron is then cut into small pieces and taken in crucibles along with certain kinds of wood and leaves of plants and then heated in charcoal blast furnaces with the lids closed. The blast is continued from four to six hours when the steel is obtained in the molten condition. Water is then sprinkled or poured on the metal, which is thus hardened on being quenched and the steel obtained in a crystalline condition.

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We give below Heyne's account of steel-making in Mysore which was published in 1814.¹ "In order to convert the iron into steel each piece is cut into three parts, making fifty-two in the whole, each of which is put into a crucible, together with a handful of the dried branches of "tangedu" (cassia auriculata) and another of fresh leaves of "vonangady" (convolvulus laurifolia). The mouth of the crucible is then closely shut with a handful of red mud, and the whole arranged in circular order with their bottoms turned towards the centre in a hole made on the ground for the purpose. The whole is then filled up with charcoal, and large bellows are kept blowing for six hours, by which time the operation is finished. The crucibles are then removed from the furnace, ranged in rows on moistened mud, and water is thrown on them whilst yet hot. The steel is found in conical pieces at the bottom of the crucibles, the form of which it has taken. The upper or broader surface is often striated from the centre to the circumference. The iron ore used is magnetic iron sand common all over the coast and even found on the sea-beach near Madras." The steel thus obtained is heated again in closed crucibles so that the excess of carbon is burnt out. Dr. Heyne also publishes a letter from Mr. Stoddart that even up to his time, not to speak of Indian steel of the Middle Ages, " Indian steel was decidedly superior to any other description of steel."

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¹ Heyne's "Tracts on India, historical and statistical," p. 359.

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The well-known traveller Dr. Buchanan who visited Southern India in 1800 also gives a similar account of steel-making.¹ " In each is put one-third part of a wedge of iron, with three rupees' weight of the stem of " tayngada " or cassia auriculata and two green leaves of the " hugivany " which is no doubt a convolvulus or an Ipomea with a large smooth leaf; but never having seen the flower, I could not in such a difficult class of plants attempt to ascertain the species. The mouth of the crucible is then covered with a round cap of unbaked clay and the junction is well luted." The crucibles are then dried and heated in a charcoal furnace fed with hand-bellows. The operation is conducted in four hours. When the crucibles are opened, the steel is found melted into a bottom with evident marks on its superior surface of a tendency to crystallization, which shows clearly that it has undergone a complete fusion. The steel is subjected to heat a second time in closed crucibles until the metal is obtained in a suitable condition.

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¹ Buchanan's " Travels from Madras through Mysore, &c.", p. 308.

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Syed Hossain Bilgrami in his lecture on " Iron industry in the Hyderabad and Deccan " before the Iron and Steel Institute has given a similar narrative of the crucible process of steel-making in the Nizam's Dominions, the wood used " being a species of cassia, very common in the country and known as cassia tora and the leaves those of calatropis gigantea."²

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² Syed Hossain Bilgrami : Journal of Iron and Steel Institute, 1899, Vol. II, p. 75.

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A similar method of manufacturing cast-steel was prevalent in Ceylon from early times, though the native method of steel-making has almost been beaten out of the country by foreign competition. Mr. Ananda K. Kumarswamy writes in his Mediæval Singhalese Art: " the steel is made in clay crucibles, each about eight inches long, two inches in diameter, and a quarter of an inch in thickness. In the crucible is put a piece of iron, with some chips of *cassia auriculata*, in the proportion of 12½ oz. iron to 5 oz. wood, in the case examined. The crucible is covered with a lid, having small holes pierced for the escape of gas; six crucibles thus prepared are embedded in the charcoal and a fire started. Very soon the woods burn off, and while this goes on the blowing is stopped. Then the blast is kept up continuously." The steel obtained in the course of a few hours is highly crystalline.

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CRUCIBLE PROCESS OF MAKING CAST-STEEL—AN INDIAN DISCOVERY.

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From the accounts given above it is evident that the traditional Indian method of making steel was the crucible process of making cast-steel in a fused condition by cementation, which process should in reality be regarded as an Indian discovery. The chemical action that takes places, as suggested by Heath, is that during the application of heat to the closed crucible the dry wood and green leaves would yield charcoal as well as an abundant supply of hydrocarbons. The *joint action of carbon and hydrocarbons* on the iron greatly facilitates the formation of steel as the European method of cementation by means of *charcoal alone* used to take six or seven days, and even fourteen to twenty days, while the Indian process takes only four to six hours. Though cementation has been mentioned by Agricola in his *de re metallica*, and though Reaumer in 1722 described the process of converting bar-iron into "blistered steel," it was only in 1800 that Mr. D. Mushet took out a patent for converting malleable iron into cast-steel by fusing it in a closed crucible in contact with carbon. "Now this specification," says Mr. Heath, "unquestionably comprises the principle of the Indian process which adopts the use of dry wood, which is a substance containing the coaly or carbonaceous principle." This opinion is confirmed by Dr. Percy who says, "It is curious that Mushet's process, so far as relates to the use of malleable iron in the production of cast-steel, should in principle, and I may add even in practice too, be identical with that by which the Hindoos have from ancient times prepared their wootz. I cannot discover any essential difference between the two." ¹ Dr. Percy, however, did not take into consideration the action of carburetted hydrogen gas produced by the destructive decomposition of wood in the Indian process, though as a matter of fact in the year 1825 Mr. Charles Mackintosh actually took out a patent for converting malleable iron into steel by exposing it to the action of carburetted hydrogen gas in a closed vessel, at a very high temperature, by which means the process of conversion into steel is completed in a few hours while by the old method it was the work of from fourteen to twenty days.

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¹ Percy's "Metallurgy," Vol. II, p. 778.

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As regards the particular kind of wood employed, the selection of *cassia auriculata* (from which catechu is obtained) and of the leaf of *convolvulus* may not be altogether an accident. It is possible that experience had taught the Indian workers the use of these two kinds of wood as affording suitable quantities of carbon and hydrocarbons to the iron so that the conversion of iron into steel could take place more quickly than with other kinds of wood.

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As regards the proportion of carbon contained in steel, the excess of carbon is burnt away during reheating. In this connection the remarks of Ritter Cecil von Schwarz, who was for some time in charge of the Bengal Iron Works Company, would be interesting. He wrote: "It is well known by every manufacturer of crucible cast-steel how difficult it is sometimes to get the exact degree of hardness to suit certain purposes, especially with reference to steel for cutting the blades, etc. With the ordinary process endeavours are made to reach the required degree of hardness by selecting such raw materials as on an average have the required contents of carbon in order to correspond with the required degree of hardness as far as possible. The natives (of India) reached this degree by introducing into their cast-steel an excess of carbon, by taking this excess gradually away afterwards, by means of the slow tempering process, having it thus completely in their power to attain the exact degree by interrupting this decarbonising process exactly at the proper time in order to cast steel of a quality exactly suitable for the purpose." ²

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² Quoted in P. C. Ray's History of Hindu Chemistry, Vol. I.

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We hope we have been able to give a trustworthy account of the process of the manufacture of Indian steel, which was an object of envy of all nations but successfully imitated by none and which supplied the materials of many a true blade of warriors both in the East and the West. It is sad to reflect that an ancient indigenous industry which attracted merchants from Persia, as narrated by Dr. Voysey, barely hundred years ago, is on the point of extinction; but as even the darkest cloud is not without a silver lining, a distinct ray of hope is visible in the not very distant horizon presaging that India will yet regain her lost iron industry under modern scientific conditions together with other attendant industries depending upon iron.

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