Metallurgical Marvels of Ancient India

Pradip tells the fascinating story of metallurgical achievements in pre-British India.

Pradip tells the fascinating story of metallurgical achievements in pre-British India.

I write this brief article inspired by the ideas and the vision articulated in the pages of Ghadar Jari Hai. Several authors have very eloquently argued in earlier issues about the need to break with the colonial legacy of adopting a Euro-centric approach to study our Indian history and culture. I wholeheartedly support this position. Whether it is the issue of a critical examination of our ancient heritage, of our Indian way of life and the philosophical outlook developed by our ancestors, or the statecraft practiced as part of a flourishing advanced civilization in the Indian sub-continent, a majority of our Indian intellectual elite gets influenced by the jaundiced Euro-centric outlook of the colonizers. The colonizers denigrated Indian achievements and destroyed our self confidence. The same is the story when we study our accomplishments in science and technology before the British colonized India. It is important for us to learn, document and disseminate our impressive heritage in all walks of life. I recall in this article some of the well known enduring symbols of Indian technological innovation and excellence in metallurgy – an area of current interest as well.

It is now a widely acknowledged historical fact that in 1600 when the East India Company was founded, the share of Britain in the then world’s gross domestic product was 1.8% only compared to 22.5 % contributed by India. By the year 1857, when Indian people rose in unison to overthrow the barbaric colonial rule in our country, we had become totally devastated by the colonizers and people were suffering from famine, poverty and mass scale deprivation in every sense of the term.

The colonial loot and plunder not only deprived us of our material wealth but also deprived us of our intellectual wealth and worth. A civilization which had contributed so much to the world till that point in time was destroyed systematically and deliberately by the colonizers and the tragedy continues to this day. We have not yet recovered. We have not yet made a clean break with that colonial legacy.

Let us take the case of metallurgy in India. It is perhaps not known to many that India was once a world leader in metallurgical science and technology. The Indus valley civilization was known for innovative use of metals like copper, lead, tin, gold and silver. Harappan sites indicate that in addition to making pure copper of 98.5% purity, alloying with tin and arsenic to produce bronzes of various kinds was being practiced. It was for example known to our ancestors that copper-tin bronze having more than 11% tin become brittle and 8-11 % tin was best for obtaining artifacts having an optimum combination of strength, ductility, toughness and shock resistance.

Zinc – The Metal from India

Based on extensive archeological evidence, Prof A K Biswas documented that the earliest artifact containing an appreciable amount of zinc anywhere in the world was from India. During the Harappan era copper used to be alloyed with tin and arsenic, but artisans in the Rajasthan-Gujarat region discovered how to produce pure zinc from zinc sulphide ore. Thus it became possible to make brass with high  zinc content. The earliest brass artifact containing more than 28% zinc which could only be made with the production of pure zinc metal, came from Taxila. According to Biswas, zinc smelting technology must have traveled west from India during the 6th and 5th century BC, as it did later again in the 18th century AD.

According to C.V Sundaram, when zinc was still a curiosity in Europe as late as 300 years ago, it had already been produced in India for 2000 years as evidenced by carbon dating of wood and charcoal specimens at the ancient mines of Zawar in Rajasthan. It is estimated that more than 30,000 tons of zinc must have been produced at Zawar mines before they were closed down and rediscovered later in the nineteenth century.
During archaeological excavations, Hegde and Craddock in Rajasthan discovered the ancient clay retorts through which pure zinc was being produced in India from natural zinc sulphide ores found in that region. This method of inverted retorts to condense the zinc vapors was indeed an innovative technology. It stood the test of time since a similar process was patented by William Champion in Bristol only in the 18th century. The large scale production of zinc in Rajasthan and widespread use of zinc and brass in medieval India, particularly the production of brass and bronze icons of intricate shapes and sizes, is a fascinating story of Indian metallurgical excellence achieved in that era.

Bidriware from India
Biswas also described the development of the famous bidri ware (the sleek and smooth dark colored metalwork with intricate designs on its glassy surface) pioneered by Indians in the 15th century. Bidri is an alloy containing 76 to 98% zinc along with copper, lead and tin. The innovative craftsmen from Zawar in Rajasthan moved south and settled in Bidar near Hyderabad. Consequently, this unique art of making wonderful metal objects flourished there for centuries, known to the world as Bidriware. Besides Bidar, Lucknow, Purnea and Murshidabad were also known as centres of Bidriware in pre-modern India.

Bronze Icons of South India: “Lost Wax” Technology
Baldev Raj and co-workers have chronicled the story of bronze icons from south India. Made by a “lost wax” process, the bronze icons of, for example, Nataraja and the excavated statue of dancing girl from Mohenjodaro are considered to be among the best symbols of the metallurgical accomplishments from ancient India. Evidence indicates that this unique metal casting technology was developed in India about 5000 years ago and received patronage from all the royal dynasties in India, from the Pallavas in 300 to 900 AD, the Cholas (900 to 1300 AD) and the Vijaynagar empire in 16th and 17th centuries. That is how this technology has been preserved to this day.

C V Sundaram cites considerable archaeological evidence in support of extensive mining and smelting of copper-zinc and lead sulphide ores in Khetri and Dariba in Rajasthan and Agnigundla in Andhra Pradesh around 1100 BC.

The Iron Age was ushered in around 800 BC in India. It is established now that extraction of iron in an organized manner started in India in the sixth century BC.

Delhi Iron Pillar : The Rustless Wonder
Known as the “Lohe-ki-Lat”, the Delhi iron pillar was built in the 4th century AD to commemorate the accomplishments of the Gupta era. It is over 7 meters feet tall with a diameter of 16.5 inches at the bottom and 12.5 inches at the top, weighs 6.5 ton, and is considered to be the biggest hand-forged block of wrought iron from antiquity. The pillar has not corroded for more than 1600 years now, and it remains a matter of scientific curiosity and investigation. There have been several attempts by metallurgists to reproduce this non-corroding material based on our modern understanding and using today’s technologies.

Wootz Steel: An Advanced Material of the Ancient World Invented in India

Sharada Srinivasan and S Ranganathan in their book, “India’s Legendary Wootz Steel”describe the incredible saga of Damascus swords made from Indian wootz steel. According to the authors, just as ‘Arabic numerals’ reached the West through the Arab world, although they were essentially based on the decimal system of Indian origin, the previously unparalleled Indian traditions of steel and sword making became known to Europe through the Islamic world. Indian wootz steel ingots are believed to have been used to forge oriental Damascus swords, which took the Europeans by surprise during the crusades of the 12th to 13th century. Wootz steel (anglicized version of Kannada-Telugu word “ukku”) is the known to have excellent strength and toughness but also enough ductility to made fine, sharp blades.

The authors also describe how British colonialists, during and following the Ghadar of 1857, ordered the destruction of all the wootz steel swords. During his reign from 1782 to 1799, Tipu Sultan who fought four bloody wars against the British colonialists, is known for his bravery and heroism. What is perhaps not so well known is that Tipu hailed from the land of wootz steel as well as Damascus blades, in Mysore. The fabled “swords of Tipu Sultan” are not only a testimony to Indian technological skills in metallurgy but are also known as an incandescent symbol of Indian resistance to colonial British rule. Buchanan in his travelogue provides detailed accounts of the advanced steel technology being practiced in South India in that period.

Damascus steel swords are considered to be an advanced material consisting of a wonderful combination of strength, ductility and toughness – a dream even today for the metallurgists trying to invent advanced high strength steels. According to Srinivasan and Ranganathan, apart from its rich historical significance, wootz steel also played an important role in spurring developments in 19th century metallurgy. The best known scientists of the time such as Michael Faraday investigated this unique material, which in many ways paved the way for the spectacular materials revolution in the twentieth century leading to the invention and large scale production of modern alloy steels. Many studies using nanotechnology are being made on wootz artifacts in order to reconstruct their method of manufacture.

This brief story of Indian metallurgical excellence is only a small part of the glorious legacy bequeathed to us by our forefathers. There was something vibrant, creative and wonderful here which nourished and made us world leaders in the not too distant past. It is our duty to rediscover and reconnect with this proud heritage of ours.

Dr Pradip is a well known material scientist from IIT Kanpur and University of California at Berkeley. He has written several research papers in Material Science and has several patents to his credit. Pradip is a Fellow of Indian National Academy of Engineering and currently heads the Process Engineering Group at the R & D Centre of Tata Consultancy Services.

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