Iron - The secret weapon?
Her armies would surprise the Egyptians at Kadesh, deliver Samaria, the capital of the Kingdom of Israel, from a Syrian army, and overwhelm the defenders of Babylon. The Hittites seemingly appeared out of nowhere, struck decisively, and then, almost as quickly, disappeared. From a distance, success seemed only explainable in mythical terms, unrelated to superior tactics, training or fighting ability. There was the suspicion (or hope) that it was the iron in their weapons that gave them an edge. The primitive bronze weapons of their enemies broke against the iron blades wielded by the Hittite soldiers. The story of a superior race of people, with an advanced technology, reinforced the special status conferred by their mention in the Bible. Perhaps the saviors of the Israelites were human agents of a Divine plan of retribution or salvation. The secret of iron had been revealed to them as part of that plan. The Hittite legend is not entirely false, since they are credited with the "discovery" or development of iron technology, even if their exploits have been somewhat embellished with time.
Iron probably was not the mythical secret weapon which explained Hittite military success. However, they did develop a smelting process capable of producing iron tools, weapons, and ornamental objects. Their process was the result of years of metal-working experience, not simply an accidental byproduct of an iron rock falling into a fire.
Discovering that rocks can melt...
The melting temperature of three metals, iron, copper, and tin, is at the heart of the Hittite discovery. Iron has a melting point of 1535 degrees C (about 2795 degrees F), copper melts at 1083 degrees C (about 1972 degrees F), and tin melts at 231.97 degrees C (about 422 F). In one sense, the history of metals involved two very simple, but separate ideas. The first was the discovery that solid rock would melt. The second was the development of a process capable of producing the temperatures at which ore would turn into liquid.
Tin may have represented the breakthrough metal. With a melting point of 232 degrees C, it probably was one of the earliest metals observed to liquefy. In terms of the smelting process itself, the temperature threshold would be relatively easy to achieve and sustain. Where or when such knowledge was first acquired would be difficult to pinpoint. There is evidence that it was first used in the Zagros Mountains of what is now western Iran after 3500 B.C.. Whether that knowledge moved west or was discovered independently, tin mining and smelting was occurring in southern Anatolia shortly after that. About 60 miles north of Tarsus is an ancient Anatolian village called Göltepe in the Taurus Mountains. While its population was small, at only 500 or 1,000 people, it had been occupied between 3290 B.C. and 1840 B.C.. Economic life revolved around a nearby tin mine. An extensive network of tunnels, some over a mile in length, had been dug into the mountain. (It may have been the scene of some of the earliest mining accidents, since the skeletons of children have been found there.)
The mining process at Göltepe began by heating the mine face. Fires would soften the ore so that it could be chiseled more easily. Once the ore had been hauled to the surface it was smelted. Smelting involved heating in small ceramic crucibles. Charcoal, which was layered between the tin ore, provided the heat source. Temperatures may have reached 2,000 degrees F, possibly achieved through the use of reed pipe "bellows."
The Bronze Age
Tin had a market in its own right. However, the miners of Göltepe found the tin market sustained by the demand for bronze. Bronze was the alloy produced when tin was added to copper. Copper, with a melting temperature of 1083 degrees C, would seemingly have been a much more difficult metal to decipher than tin. Despite that apparent obstacle, copper was in use long before tin. Copper beads from sites in northern Iraq, have been dated to 9000 B.C. Catal Hüyük, another Hittite city, may have been smelting copper, as well as lead, as early as 5400 B.C.. The Copper Age (or early Bronze Age) has been assigned various starting dates - 5000 B.C., according to some, 4000 or 3500 B.C. according to others. The Bronze Age, similarly, has a starting date of 4000, 3000, 2500, or even 2000 B.C.. The Shang Civilization (1700 - 1100) is credited with starting the Bronze Age in China.
The Bronze Age ended with the beginning of the Iron Age. Unfortunately there is no agreement on just when the Iron Age began. Some date its beginnings to 1500 B.C., about the time the Hittites may have started working with iron. Others give it a range of between 1500 and 1000 B.C.. Still others have dated it to 1200 B.C., when the Hittite Empire came to an end. Others assign its beginnings to around 1000 B.C., some 200 years after the end of the Hittite Empire. The basis for such a comparatively late date is that iron usage had become commonplace around the Mediterranean by that time. The start of the Iron Age also depended on location. The Halstatt Iron Age in central Europe is dated to 850 B.C. and Egypt's Iron Age began around 700 B.C.. Indian cities entered the Iron Age sometime after 600 B.C.. The Iron Age has continued to the present, even if its beginnings are uncertain.
Uncertainties about the beginning dates of the Copper, Bronze or Iron Ages stem from their broad meanings. They are intended to describe general stages of human development, rather than specific events or accomplishments. They could not have occurred without the discovery of copper or iron, but the date of the discovery or first use did not necessarily mark the beginning of an age. The occasional crafting of trinkets or tools proved that metals were being used, but small-scale or occasional production did not amount to an "Age." The Bronze or Iron Ages required, not only the ability to produce bronze or iron products on a large scale, but also fairly widespread use. An Age, in other words, demanded a large-scale market, i.e., an economy somewhat larger than that of a local village or tribe.
Gold may help to illustrate the problems in defining a metals age. While gold articles and the work of ancient goldsmiths are the most enduring and familiar treasures of the ancient world, the likelihood of an Age of Gold is extremely remote. The experience and skills of early craftsmen demonstrated a thorough knowledge of metalworking. Unfortunately, the scarcity of gold limited the market to ornamental items, since only kings or wealthy individuals could afford it.
The Hittites may have been able to produce and work iron, but production was too limited to support the mass markets demanded for designation as an Iron Age. One Hittite king, in the 13th Century B.C., apologetically sent an iron dagger blade to another king. The amount of iron the foreign monarch had requested, he explained, would not be ready for some time. The Bronze Age thus saw the anomaly of an iron-making capability and limited demand for the metal before the Iron Age began.
The Iron Age
The modern blast furnace produces temperatures hotter than 1600 degrees C (3000 degrees F), well above the melting point of iron (1535 degrees C) (2795 degrees F). An initial question, in analyzing the capabilities of Hittite technology, is whether it could have reached the melting point of iron or, if it could, whether that temperature could have been sustained for any period of time. The immediate response is that it must have achieved those goals, since the evidence suggests that the Hittites were regularly producing iron. That would be a remarkable achievement, given what one would expect from an ancient technology. However, there may be two other factors which might impact any analysis. The first is the fact that while the melting temperature of pure iron is something of an absolute, the addition of carbon, (a process known as carburization), can reduce the melting point to about 1170 degrees C (2138 degrees F). A second factor is the possibility that iron could be produced and worked at a temperature below its melting point.
Modern iron making offers a window into the past. In some ways the basic technology, if more refined and systematized, has changed little in 3500 years. The goal of the modern blast furnace, to produce a pure iron product, is the same as that of the ancient furnace or oven. The modern furnace may generate hotter temperatures and better iron, but the basic idea revolves around heat generation and temperature.
Iron, in its natural state, has a tendency to combine with oxygen, producing iron oxide, commonly observed as rust. Removing impurities, starting with oxygen, has been the universal problem encountered by iron makers. The secret to eliminating oxygen is to use a substance, known as a reducing agent, with a greater affinity for oxygen than iron. Charcoal and coke have been the two most commonly used reducing agents. Both serve dual purposes. As fuels, they generate the temperatures capable of melting iron. As carbon sources (coke is nearly 90 percent carbon), they carburize the iron, reducing its melting point and also serve as reducing agents to remove the oxygen. Oxygen is not the only impurity found in iron ore. Some can be removed with limestone, which, like a reducing agent, will combine with such impurities, lowering their melting point. The slag which forms separates from the iron and floats to the surface.
One of the problems faced by the Hittite iron makers involved the amount of carbon to be added. Additional amounts of carbon may lower the melting point of iron, but also make it extremely difficult to shape. Cast iron, the product, can only be shaped by use of a mold. As the liquid cools it assumes the shape of the mold. Wrought iron, in contrast, contains far less carbon, but requires a temperature close to the melting point of pure iron. The advantage over cast iron is malleability. Normally wrought iron is made with an additional ingredient, silica, found in sand. Steel includes a limited amount of carbon or the addition of other elements, such as manganese or nickel.
The Hittites appear to have produced an iron which could be reheated and worked, suggesting that their product was a form of wrought iron or some version similar to carbon steel. Charcoal was used as the reducing agent, layered with the iron ore in shallow hearths. The temperatures may not have reached the melting point, but they were sufficient to remove the oxygen after several hours, leaving a shiny metal. Limestone may have been used to remove other impurities or iron workers may have reheated the iron and hammered out the impurities which were left.
A Neanderthal dead-end or a continuing tradition?
The study of human origins has often tried to trace a direct line of evolution from ancient species down to modern man. The Neanderthals and Australopithecus are not considered direct ancestors of today's humans. They represent instead, side-branches which died out. The key question, in relation to the Hittites, is not whether they deserve the credit for being the first to discover iron, but whether it was their discoveries which set the stage for the Iron Age. In other words, did they represent the true ancestors of the Iron Age or, like the Neanderthals, did their independence and secrecy turn their technological achievements into dead-end curiosities?
In some ways the question of whether iron technology originated with the Hittites, depends on the nature of the technology. Was it so specialized as to prevent duplication? or would a general knowledge of metalworking provide enough insight to allow for intelligent guesswork about the formulation and process? During the reign of Tudhaliyas IV (1265 - 1240), the Assyrians took the kingdom of Isuwa and its copper mines from the Hittites. Would the miners, engineers, and metallurgists living there only have known about copper technology or would their knowledge extend to iron? Perhaps foreign visitors to Hatussa could obtain sufficient information through observation. Was it possible that even the limited samples of iron which the Hittites sent away could be reverse-engineered to reveal secrets about the processes used to create them? Little is know about the final days of the Hittite Empire. Perhaps, in the confusion and tumult many chose to leave, taking their technological know-how with them. Some may have been lured by offers from rival kingdoms or found refuge in faraway cities. Alternatively, they may have been massacred in the savage fighting which descended on Hatussa or perished in the fire which destroyed it.
Having developed a smelting process for iron, the Hittites would have been reluctant to share their secret. They did take steps to limit access by maintaining a monopoly on production. How successful were those efforts? and, if they were successful, did that mean that the Hittites had effectively severed their ties to the Iron Age they helped create? That would suggest that the iron technology associated with the Iron Age was developed independently of the Hittites. Alternatively, Hittite technology might have been transferred despite official efforts to keep it secret.
Suggestions for further reading.
S. G. F. Brandon, ed., "Milestones of History: Ancient Empires," Newsweek Books, (New York, NY 1973)
Roberta Conlan, Managing ed., "Lost Civilizations: Anatolia: Cauldron of Culture. " Time-Life Books, (Alexandria, VA 1995)
Glenn D. Considine, ed., "Van Nostrand's Scientific Encyclopedia, Ninth Edition." Wiley-Interscience, (New York, NY 2002)
Thomas H. Flaherty, Managing ed., "Lost Civilizations: Egypt: Land of the Pharaohs. " Time-Life Books, (Alexandria, VA 1992)
Janet Serlin Garber, ed. "The Concise Encyclopedia of Ancient Civilizations," Franklin Watts (New York, NY 1978)
Jim Hicks, "The Emergence of Man: The Empire Builders." Time, Inc., (New York, NY 1974)
George P. Hunt, Managing ed., "The Epic of Man. " Time, Incorporated, (New York, NY 1961)
Johannes Lehmann, "The Hittites: People of a Thousand Gods." The Viking Press, (New York, NY 1977)
David E. Newton, "Chemical Elements From Carbon to Krypton." UXL, An Imprint of Gale, (Detroit, MI 1999)
V. H. Patterson and M. J. Lalich, "Early Progress in the Melting of Iron, from paper "Fifty years of progress in the inoculation of cast irons," presented at the 44th International Foundry Congress, held in Florence, Italy in 1977.
"Reader's Digest History of Man: The Last Two Million Years." The Reader's Digest Association, (New York, NY 1974)
Bruce Wetterau, "World History: A Dictionary of Important People, Places, and Events, from Ancient Times to the Present." Henry Holt and Company (New York, NY 1994)
"The World Book Encyclopedia, 2003 Edition." World Book, Inc, (Chicago, IL 2003)