MYSTERY OF INDIAN IRON PILLAR

In the capital of India - New Delhi, is situated a place called meharauli. This place is famous not because of the nature's beauty but because of the Iron pillar. It was built as a memorial to a King named Chandra.

The height of this massive pillar is 22ft. It has a diameter of about 4 and half feet and is a solid shaft of wrought iron with an ornamental top. Its metallurgical skill speaks volumes for the workers and the era in which it was constructed. Scholars believe that it must have been constructed in the 5th century.

Iron pillar attracts attention not because of the ancient time in which it was ,constructed, but because of its unimpairment. Despite years of exposure to wind and rain it has not rusted or has even weakened.

Many theories have been put forward regarding the pillar not having rusted. The most acceptable theory is that of Erich Von Daniken. In his book " chariots of god ", he has written that structures like pyramids, and Iron Pillar could not have been constructed or built without the "Super Intelligent" forces.

Any how, the theory is something which is open to criticism. The startling fact is that how can the Iron pillar stand there so strongly without any patch of rust, even though scientific tests have proved that the iron used is not hundred percent pure. And when science fails, the myths and legends obviously take birth.

Over the years, myths have surrounded this pillar too. It is said that if anyone is able to encircle the pillar, that person is supposed to be very fortunate. Perhaps, some have succeeded in encircling it or perhaps, some day someone will be able to.

It is true that the actual nature of the material used has not been known. But this also does not mean that science should give way to myths and suppositions. Science is getting modernized day by day. May be some day scientists will be able to know the true nature of the metal from which the column is made of. And the curtain of mystery would be raised away from the dark, tall round Iron Pillar.

Experts at the Indian Instituteof Technology have resolved the mystery behind the 1,600-year-old iron pillar in Delhi, which has never corroded despite the capital's harsh weather.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, according to R. Balasubramaniam of the IIT.
In a report published in the journal Current Science Balasubramanian says, the protective film was formed catalytically by the presence of high amounts of phosphorous in the iron—as much as one per cent against less than 0.05 per cent in today's iron.
The high phosphorous 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 furnaces, on the other hand, use limestone in place of charcoal yielding molten slag and pig iron that is later converted into steel. In the modern process most phosphorous is carried away by the slag.
The pillar—over seven metres high and weighing more than six tonnes—was erected by Kumara Gupta of Gupta dynasty that ruled northern India in AD 320-540.

Stating that the pillar is "a living testimony to the skill of metallurgists of ancient India", Balasubramaniam said the "kinetic scheme" that his group developed for predicting growth of the protective film may be useful for modeling long-term corrosion behaviour of containers for nuclear storage applications.