India’s Magical Ancient Pillar

The Delhi Pillar Is a Genuine Out-of-Place Artifact

In June, 1987, I took a tour group to China, Inner Mongolia, Tibet, India, Nepal and Kashmir on a grand odyssey to many of the sacred places of Asia. While visiting India, one of the highlights, for me, was to see what is called the Del­hi Pillar, a column of wrought iron that stands in the courtyard of Kutab Minar, in what is now the capital city of New Delhi. In the past the column has also been called the Singh Stambh, the Ashoka, and the Lion Pillar. It stands 23 feet 8 inches tall, averages 15 inches in diameter and weighs approximately 6 tons. The real enigma is that it has not rusted in the millennium and a half of its existence.

As I stood in person next to this very unassuming yet impressive column of black metal, I touched its surfaces and felt like the astronaut in 2001: A Space Odessey reaching out toward the alien black monolith found on the Moon.

For the Delhi Pillar is a genuine out-of-place artifact, a silent tribute to advanced metallurgical skills made by un­known artisans who possessed a secret knowledge handed down to them from a forgotten civilization. The Pillar con­tains such a level of sophistication that its inherent wisdom is today just beginning to impact upon our present man­ufacturing technology.

The Delhi Pillar is a solid shaft of wrought iron made up of iron discs expertly welded together in a fashion that the welding marks are hardly discernible. The iron for the Pillar is believed to have originated from the Bihar region and may have been manufactured there, for the forest people of Bihar are reputed to have known of advanced forms of the art of forging iron and steel in their clay furnaces for untold thousands of years.

An inscription still plainly seen on the Pillar’s base is an epitaph to King Chandra Gupta II, who died in AD 413. So it is known the Pillar is at least 1,600 years old, probably older. The monument was first erected at Udayagirl near the present-day city of Bhopal in central India. The Pillar first stood in the temple of Muttra capped with a Garuda, an image of the bird incarnation of the god Vishnu. In the year 1052 Moslem invaders tore off the Garuda and took away the Pillar, eventually re-erecting it where it stands today, in what was then the courtyard of the Quwwat-ul-Islam Mosque, the very first mosque built in India. How long the Pillar had been in the previous temple, however, is un­known.

The most fascinating feature about the Delhi Pillar is the fact that, despite it being well over a millennium and a half in age, its iron constitution is nevertheless in a remarkable state of preservation. The inscription on its base still appears clearly cut with very little evidence of weathering.

Immediately above the base the Pillar surface is slightly rough and pitted due to corrosion from soil moisture in­roads into forge-welding marks and areas damaged by its re-erection in the past.

From here on up, the surface is very smooth, like polished brass, and in the top portion this smoothness persists, with only occasional instances of pockmarks and weathering.

At the column’s very top is a rust-free decorative “bell” that is, itself, a marvel of blacksmithing, consisting of sev­en parts. These individual components were shrunk-fit around a hollow cylinder and then joined to the main body with the use of an insert.

The mystery is, one would expecte that any equivalent mass of iron—subjected to the Indian monsoon rains, winds and temperatures for 1,600 years or more—should have been reduced to a pile of rust long ago. But the Delhi Pillar still stands, unthreatened by the elements. What are its secrets?

In 1911, Sir Robert Hadfield made an analysis of the pillar’s ingredients and found it be composed of: Iron­99.72%, Phosphorus-0.114%, Carbon-0.08%, Silicon-0.046%, Nitrogen-0.032%, and Copper and other elements­O.114%. Hadfield found the iron to be entirely free of inclusions, and in terms of homogeneity and purity ranked it with the best Swedish charcoal irons of his day.

The purity level is particularly surprising, for it was not attained in Europe until the nineteenth century, and was certainly a technological anomaly for the fifth century. The level helps to explain, in part, the Delhi Pillar’s survival. The process of rusting requires a catalyst, and with few impurities present in the iron, oxidation would have been re­tarded. However, the purity alone does not fully answer its persistent existence.

In 1953, J. C. Hudson published the results of experiments in which he exposed steel and zinc plates 4 x 2 and one-eighth inches in size to the atmospheric conditions at Delhi over one-year periods. What he discovered was that the corrosion rates for metals in this locale are low, and he proposed this finding as the answer to the iron Pillar’s preservation.

However, as W. H. J. Vernon pointed out, significant iron rusting occurs when air humidity exceeds 70%. Accord­ing to the Indian Meteorological Office, the humidity factor at Delhi reaches 74% during two months out of the year, in January and August. Admittedly, this is less moisture than other parts of India and the world, and this low level does indeed help the life of metals, but high moisture during two months every year for over 1,600 years time should still have been active enough to severely rust even the most durable of modern irons.

So weather conditions, while an aid, are not the whole answer to the Delhi Pillar puzzle either.

Another contributing factor to the Pillar’s long life is its resistance to water. The shaft below ground is covered with a rust layer one-half inch thick, with corrosion pits three inches deep. This is a result of the iron’s constant contact with the soil, which holds a certain percentage of moisture no matter what the weather or temperature. What has happened to the Pillar below ground should have also happened to the shaft above ground as the result of expo­sure to rain and dew, but it did not.

The reason for this is that the column is unusually conducive to heat absorption and retention. This causes rapid evaporation of water droplets accumulating on the Pillar, even at night. The result is the Pillar has a built-in mecha­nism for keeping itself as dry and moisture-free as possible.

The real focus point of the mystery centers on the chemistry of the Delhi Pillar’s surface. When Hadfield tested samples from the ancient column in 1911 in a laboratory with a 70% to 75% humidity factor, he discovered that the internal newly exposed iron rusted in four days, as any normal iron sample would. But the iron taken from the outer edge of the Pillar would not rust at all. In the early 1970’s, G. Wranglen of the Royal Institute of Technology in Stock­holm found that the entire Delhi column is covered with an oxide film of metallic sheen, blue-black in color, between 50 and 600 millicrons (a millionth part of a millimeter) in thickness. In an experiment conducted by Wranglen at Delhi, a small portion of this film was scraped off. In one day rust appeared on the bared iron patch below; but within a week, the rust had undergone a chemical change, turning it into a new layer of film and preventing further oxida­tion.

Wranglen believes that the high phosphorus, low sulfur content of the iron encourages the formation of this self-protecting coating. Aiding in the process further, the outer surfaces—especially where the original surface can be de­tected—have been found to contain a higher percentage of silicon, a rust retarding agent. This appears to have been intentionally impregnated into the column at the time of its creation.

Still another aid is the Pillar’s highly polished smoothness. Not long ago, Bell Laboratories perfected a technique that rust proofs all metals, called ion-milling. By this process the metal surface is made so smooth that oxygen atoms cannot adhere to it and commence the rusting process.

Like the production of the iron in the Delhi Pillar itself, these techniques of metal preservation are far beyond the abilities of the fifth century artisans who were supposed to have made the Pillar.

What this suggests is a far older origin, older than the inscriptions that must have been simply added onto it at a later date—older perhaps by several thousands of years. This is borne out by the fact that no other Indian iron works dating to the fifth century can compare with the Delhi Pillar.

At Manud near Dhar are the remains of a second iron pillar called the Dhar Column. It once stood over fifty feet tall, but now lies broken in three pieces with a total length of 43 feet 4 inches. It too was made with welded discs, and it too has a high purity level of iron, though not anywhere as high as the Delhi Pillar. The one difference is the Dhar Column is heavily corroded, its surface pitted, and there is evidence it collapsed in about the fourteenth century from welding weaknesses compounded by advanced rusting.

It is clear the Dhar Column was a fifth century attempt at copying the far older Delhi Pillar—an attempt that failed in time, because it did not incorporate secrets of metal preservation unsuspected by the fifth century metallur­gists, nor detected by them as they studied the Delhi Pillar model.

In 2007, Ramamurthy Balasubrahmaniam, a professor of metallurgical engineering at the Indian Institute of Technology at Kanpur, announced the development of a new type of corrosion-resistant iron. It is called ductile phos­phorus iron, and commercially it will prove to be highly beneficial for construction engineers who use iron supports in damp or submerged environments such as bridges, and especially encased in wet concrete. So far test samples, produced by ITT Kanpur, submersed in acidic solution have remained corrosion-free compared with commercially available steel test controls which quickly began forming rust when subjected to the same solution. Other test sam­ples and similar controls showed the same results when embedded in simulated concrete solution.

What is amazing is that Balasubrahmaniam admits that his pioneering development of the new iron is based sole­ly on his personal research into the mystery of the Delhi Pillar. The Times of India, in its April 24, 2004-edition that first announced the professor’s initial work, headlined their article: “History Comes to the Aid of Chemistry in Beat­ing Rust.” The professor himself stated, “There is an exciting future in developing phosphorus irons. The beacon of light shining the way to the future is the Delhi Iron Pillar, with its tested proof of corrosive resistance.”

As early as 1990, Balasubrahmaniam focused his attention primarily on the high purity of the iron used in the monument, the high phosphorus content and relative absence of sulfur and magnesium in the metal, the composi­tion of its grain structure, and a process called passivity enhancement as all having been somehow utilized in its pro­duction. He also, at first, suspected that there may have been an initial exposure to an alkaline and ammoniacal appli­cation, as well as other surface coatings provided after the metal’s manufacture.

Balasubrahmaniam believes the Pillar is a “living example of an object made by the powder metallurgical route.” This conclusion came after a microprobe analysis revealed that its metal “composition of copper, nickel, manganese and chromium was uniform through several millimeters into the samples from the surface.” In fact, the consistency is such that the professor referred to the inherent materials as “nano-powder.” He likewise noted that the metal’s mi­crostructure shows a wide variety of complexities, proving the iron was obtained by direction reduction process rath­er than casting. “The pillar is a solid body with mechanical strengths throughout.”

Careful analysis has shown that 40- to 50-lbs. lumps of iron served as the raw material used in the production pro­cess. “Research has indicated that the pillar was manufactured with the pillar in a horizontal position, and the addi­tion of the lumps was from the side.” Balasubrahmaniam commented further, “This is one aspect that is not well understood (from a leading-edge metallurgical perspective) and may be called a mystery. This is the unknown method by which the iron lumps were forged to produce the massive six-ton structure.”

The professor soon concentrated his ongoing studies on the monument’s high phosphorus content, and it was in this regard that he made his breakthrough discoveries. “The presence of phosphorus,” he concluded, “is crucial to the corrosion resistance.” He also surmised that the original ore “must have been carefully chosen so that a relatively high amount of phosphorus would result in the extracted metal.” The enigma is just where such a specialized ore would have originated.

However, the main question that remains unanswered is, if the chemical composition and processing inherent in the Delhi Pillar is so sophisticated that modern metallurgists are just now discovering its secret properties—and like­wise are only beginning today to find ways of applying it—from where did the metal workers of a millennium-and-a­half ago or older acquire this same knowledge? This is indicative of a form of technology that had to have been the re­sult of many centuries of experimentation by trial and error. Yet we do not find evidence of such developmental stag­es having existed at any point in the fifth century, or before or since. Clearly, this was a special knowledge that had to have been inherited from a much older but forgotten civilization long lost to recognized history. In our modern civil­ization today, we are only treading the same pathways of discovery which someone else in dim antiquity traveled long ago.

Copyright 2009. Joseph Robert Jochmans. All Rights Reserved. Visit our website at:

By Joseph Robert Jochmans, Lit.D.

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