Sharada Srinivasan

The Archaeometallurgical Implications of New Findings of Traditional Crafts of Making High Tin ‘Delta’ Bronze Mirrors and ‘Beta’ Bronze Vessels in Kerala State of South India

New metallurgical and ethnographic observations of the traditional manufacture of specular high-tin bronze mirrors in Kerala state of southern India are discussed, which is an exceptional example of a surviving craft practice of metal mirror-making in the world. The manufacturing process has been reconstructed from analytical investigations made by Srinivasan following a visit late in 1991 to a mirror making workshop and from her technical studies of equipment acquired by Glover in March 1992 from another group of mirror makers from Pathanamthita at an exhibition held at Crafts Museum, Delhi. Finished and unfinished mirror from two workshops were of a binary, copper-tin alloy of 33% tin which is close to the composition of pure delta phase, so that these mirrors are referred to here as ‘delta’ bronzes. For the first time, metallurgical and field observations were made by Srinivasan in 1991 of the manufacture of high-tin ‘beta’ bonze vessels from Palghat district, Kerala, i‥e of wrought and quenched 23% tin bronze. This has provided the first metallurgical record for a surviving craft of high-tin bronze bowl making which can be directly related to archaeological finds of high-tin bronze vessels from the Indian subcontinent and Southeast Asia. New analytical investigations are presented of high-tin beta bronzes from the Indian subcontinent which are some of the earliest reported worldwide. These coupled with the archaeometallurgical evidence suggests that these high-tin bronze techniques are part of a long, continuing, and probably indigenous tradition of the use of high-tin bronzes in the Indian subcontinent with finds reported even from Indus Valley sites. While the source of tin has been problematic, new evidence on bronze smelting slags and literary evidence suggests there may have been some sources of tin in South India.

Crucible Steel in South India-Preliminary Investigations on Crucibles from Some Newly Identified Sites

European accounts from the 17th century onwards have referred to the repute and manufacture of “wootz’, a traditional crucible steel made especially in parts of southern India in the former provinces of Golconda, Mysore and Salem. Plinys Natural History mentions the import of iron and steel from the Seres which have been thought to refer to the ancient southern Indian kingdom of the Cheras. As yet the scale of excavations and surface surveys is too limited to link the literary accounts to archaeometallurgical evidence, although pioneering exploratory investigations have been made by scholars, especially on the pre-industrial production sites of Konasamudram and Gatihosahalli discussed in 18th-19th century European accounts. In 1991–2 during preliminary surveys of ancient base metal mining sites, Srinivasan came across unreported dumps with crucible fragments at Mel-Siruvalur in Tamil Nadu, and Tintini and Machnur in Karnataka and she collected surface specimens from these sites as well as from the known site of Gatihosahalli. She was also given crucible fragments by the Tamil University, Tanjavur, from an excavated megalithic site at Kodumanal, dated to ca 2nd c. Bc, mentioned in Tamil Sangam literature (ca 3rd c. BC-3rd c. AD), and very near Karur, the ancient capital of the Sangam Cheras. Analyses of crucible fragments from the surface collection at Mel-Siruvalur showed several iron prills with a uniform pearlitic structure of high-carbon hypereutectoid steel (∼1–1.5% C) suggesting that the end product was uniformly a high-carbon steel of a structure consistent with those of high-carbon steels used successfully to experimentally replicate the watered steel patterns on ‘Damascus’ swords. Investigations indicate that the process was of carburisation of molten low carbon iron (m.p. 1400° C) in crucibles packed with carbonaceous matter. The fabric of crucibles from all the above mentioned sites appears similar. Preliminary investigations on these crucibles are thus reported to establish their relationship to crucible production of carbon steel and to thereby extend the known horizons of this technology further.

Iron Age Beta (23% tin) Bronze: Peninsular Indian Bowls of Adichanallur, Nilgiris and Boregaon

ABSTRACT As-cast binary copper–tin alloys with over 15% were generally not much in use in antiquity as they get embrittled at higher tin contents due to the increasing presence of the intermetallic delta phase compound. Even so, the unusual and skilled use of a higher tin binary bronze alloy, known as wrought and quenched high-tin beta bronze, is found, especially from some Iron Age or megalithic sites in southern and peninsular India, around the early first millennium BCE. They are closely approximating to the composition of the pure beta phase of 22.9% tin, which is an intermetallic compound. This article presents some of the micro-structural evidence of heavily hot-forged, carinated, and perforated bowls from the site of Adichanallur, Tamil Nadu. They rank amongst the most finely wrought examples of beta bronze known in the world, with continuing traditions into the medieval Chola Tamil region and contemporary period. A process of experimentation with thermomechanical processes in the Peninsular Indian Iron Age is also suggested, since it slightly differed from an example of a vessel with 21% tin that was only cast and quenched, found in Boregaon from the Vidarbha megaliths of Maharashtra in the Central Deccan.

A tale of Wootz steel

The extraordinary romance and thrilling adventure associated with the tale of wootz steel shows how Indian metallurgists were the world leaders in antiquity in the manufacture of this legendary high-grade steel. In many ways this material was brought to global attention by the writings of Cyril Stanley Smith. Modern metallurgy and materials science rest on the foundation built by the study of this steel during the past three centuries.

Copper Smelting Slags at Ingaldhal Mines, Karnataka: Early Historic Satavahana Links

The study of old mining sites from archaeometallurgical perspectives is an area which is still not systematically undertaken in the Indian context. Whereas geological survey reports, both present and past going back to British geological reports, have generally taken care to report old workings, the finds of archaeometallurgical slag heaps have not merited that much attention. This paper reports the explorations into finds of old workings for copper mining in the region of Ingaldhal, Karnataka. A slag heap was also indentified in the vicinity, with russet coloured ware associated with the early historic Satavahana period. Analyses of the slags confirmed them to be from copper smelting, very likely from sulphide ores. Given that some old timbers from the Ingaldhal mine have yielded carbon dates of the 1–2nd century, this is consistent with the notion that copper could have been mined and smelted from this region by at least the early historic Satavahana period. Given that inscriptional records of early mining activity are not very common; such field-based investigations assume greater importance in piecing together the probable historical trajectories.

Ultrahigh-carbon “wootz” from crucible carburization of molten iron: Hypereutectoid steel from “Tamil Nadu Process” at Mel-siruvalur

ABSTRACT As European and Mediterranean accounts indicate, India has been famed for the production of steel, apparently made by crucible processes. Late medieval traveler’s accounts record the making of “wootz” steel in several places in southern India. This material was used for the fabled Damascus swords, which were later found to be of ultrahigh-carbon steel. Whereas studies on Asian crucible steel making from India, Central Asia and Sri Lanka have discussed various processes ranging from co-fusion of cast iron and wrought iron to solid-state carburization of wrought iron, it has been difficult to find clear evidence relating to an end product of ultrahigh-carbon steel. In this light, the archeometallurgical evidence from Mel-siruvalur in Tamil Nadu, presented in this paper, is significant in that it shows unmistakable remnants in crucibles of ultrahigh-carbon, hyper-eutectoid steel, with a likely production mechanism of molten carburization of wrought iron to steel. The favorable comparison with ultrahigh-carbon steel finds dated to early historic or megalithic times in Tamil Nadu and southern India also suggest that this method of crucible steel manufacture, which may be described as the “Tamil Nadu process”, might have been earlier or more archaic than the co-fusion process.

Vijayanagara Era Narasimha Bronzes and Sculpture: Digital Iconometry

Vijayanagara period sculptures in stone and bronze represent distinctive and rich stylistic traditions. This paper explores the usefulness of bringing together aspects of digital rendition together with iconographic and iconometric studies to better document and enhance the understanding of Vijayanagara sculpture. Studies on iconometric conventions and iconographic aspects have a role to play in terms of gaining more insights into the traditional modeling of such sculptural examples. This is relevant especially given that the images have had their own individual trajectories in the course of time, as for example some of the images that were damaged or broken. One of the points of interest in terms of studies in 3D modeling and digital restoration is that apart from in situ examples of stone sculptures extant in the numerous monuments at the World Heritage Site of Hampi, there are some examples of sculpture, to be found in collections such as Kamalapura museum, Hampi, and from the region of Hampi, which have missing body parts, including of the head and torso, and which include stone portrait sculptures. Hence, comparisons with intact examples in different media can give us a better sense of the totality of the artistic vision in those examples. A major aspect that this study dwells upon is thus the identification of similar themes executed in stone, bronze, stucco, and so on and for purpose of comparisons between the iconometric aspects of modeling and portrayals of themes in different sculptural media. A 3D laser-scanned digital image generated from the Ugra Narasimha image from Hampi undertaken by KCST has been examined together with animation to explore the iconometric and iconographic aspects. Using the traditional talamana canon, a bronze Lakshmi Narasimha image from Chandragiri Museum has also been studied in relation to the well-known stone Ugra Narasimha which in itself represents a reconstructed version of a damaged image. Thus, comparisons of stone, bronze and stucco versions of Vijayanagara sculpture of Narasimha images throw intriguing light on iconometric measurements in terms of the talamana canon and in terms of the development of iconography.

Indian Digital Heritage: The Next Steps

This edited volume represents the beginnings of the journey in digital heritage of India with a focus on the digital preservation of a UNESCO world heritage site with tangible and intangible heritage artefacts of great historic value. The vision of the sponsoring agency, the Department of Science and Technology of the Government of India, in digital heritage has expanded to a larger canvas of inter-disciplinary Cyber-Physical Systems with heritage as one of the central themes. Starting with cultural heritage of Hampi, the future directions are to include other cultural heritage sites, ecological heritage, socio-cultural heritage of dwellings of cities, of music, soundscapes and spoken languages; the list goes on. With emerging technologies of underwater mapping, LIDAR scanners, drones, virtual and augmented realities, 3D printing etc., the future directions for Indian digital heritage seem endless. This chapter elaborates a few directions which have now been encapsulated as a detailed project report and submitted as guidance to the Department of Science and Technology for the next phase of funded research and development.