Iron Pillar or Ashok Stambh of Delhi

Standing at the center of the Quwwatul Mosque is an iron pillar or Indians know it by the name “Ashok Stambh”, in the name of the pillar Ashoka stands for the name of the emperor who built it and Stambh in Sanskrit meaning pillar. The pillar was erected by Ashoka who was 3^rd ruler of the Maurya dynasty from 269 BCE to 232 BCE. The pillar has inscriptions of Vishnu and Chandragupta Maurya (Ashoka’s Grandfather) in Sanskrit. Besides its historical importance the pillar is the most mysterious monument that has attracted many archaeologists and metallurgists. The metallurgic technique used to erect this pillar is still unknown.

The height of the pillar is 7.21 m, and it weighs around six tons. The date when the pillar was built and the original locations of the pillar have constantly been in discussion. Some experts say that the pillar was erected in 900 BCE, the same time when the concept of zero originated in India. For the location, a summary of views on this subject and related matters was collected in volume edited by M.C Joshi and published in 1989. More recently, opinions have been summarized again by Upinder Singh in her book Delhi: Ancient History. Metallurgists at Kanpur IIT have discovered that a thin layer of “Misawite”, a compound of iron, oxygen, and hydrogen, has protected the cast iron pillar from rust. The protective film took form within three years after erection of the pillar and has been growing ever so slowly since then. After 1,600 years, the film has grown just one-twentieth of a millimeter thick.

The high phosphorus content is a result of the unique iron-making process practiced by ancient Indians, who reduced iron ore into steel in one step by mixing it with charcoal. Modern blast furnace, on the other hand, use limestone in place of charcoal yielding molten slang and pig iron that is later converted into steel. In the modern process most of the phosphorus is carried away by the slag.

Though the Indian Institute of Technology has resolved with a somewhat clear explanation, the mystery still remains as to how the ancients knew such knowledge, who gathered such knowledge in the ancient India where the preference at that time was more on spirituality, why didn’t they pass this knowledge to the future generations, and how did they achieve such a feat.