What is the Deep Impact of Ferrous Metallurgy

Metals have made a deep impact on ancient and modern societies. Copper was the first metal to be exploited, as it melts at relatively low temperatures and can be easily molded into tools, jewelry, or weapons. However, the metal can easily bend, is brittle, and can break easily. In the ancient Near East, by the late 2nd millennium BCE, by around 1400-1300 BCE, the process of smelting and making iron tools developed. While iron could be obtained from natural sources, such as meteoric iron, these sources are limited and cannot be used to create many tools or weapons. The innovation of iron smelting opened many new possibilities for the ancient and modern worlds, forever changing how our own societies today have evolved.

Early Development of Iron and Steel

The exact origins of iron smelting are debated. It is possible this occurred already by the mid-third millennium BCE in Anatolia (modern Turkey), where a Hattic weapon made of iron was found and appeared to have derived from a smelted source. By the mid-second millennium BCE, iron tools were increasingly found in Anatolia, Mesopotamia, and Egypt. In fact, in the Late Bronze Age, from around 1400-1300 BCE, iron weapons are found in tombs, including that in the tomb of Tutankhamun. Although the gold and jewelry from his tomb are the most famous, the iron objects found have puzzled archaeologists. However, recent studies have shown that one of these weapons was made of meteoric iron, indicating that if iron smelting existed then it was very rare.

In effect, the Late Bronze Age (1600-1200 BCE) was probably a period in which iron smelting was developing but was not a widely mastered technology or a limited technology to a few places. We know Anatolia must have been an important source for iron and iron making, as texts from the ancient city of Amarna indicate a desire by the Egyptians to import iron from the Hittites, who may have been the first society to master iron making. Iron making was still very rare and trade for it was mostly done at the elite level rather than it being traded similarly as common metals such as bronze.

Undoubtedly, the Iron Age, which first began in 1200 BCE in the Near East and spread to parts of Africa and the eastern Mediterranean, saw many new developments and widespread mastery of iron making. Furnaces used for smelting iron, called a bloomery, now became well developed, where craftsmen were better able to control heating technologies to smelt iron and raise temperatures over 1000 degrees centigrade. After this time, and throughout the 1st millennium BCE, iron making technology spread throughout the Old World, reaching China by the 5th century BCE. Wrought iron became the primary type of iron made and forged into weapons and tools. This type of iron mostly contained iron but also had some carbon that helped to strengthen iron so that it was not too brittle. Already, it was known that adding carbon to make steel strengthened weapons so they did not easily break during battle or in using tools.

Iron likely helped forge many empires that developed in the 1st millennium BCE, where the control of production now gave these states military advantage (Figure 1). While the incentives of gaining military advantage helped spread ferrous technologies, including iron and what became steel making, many secondary effects of this innovation began to develop. First, iron and steel produced not only better swords, spears, and axes, but cutting tools, hammers, saws, and other implements all benefited. This now made it possible to radically transform the landscape. New technologies soon emerged after the innovation of ferrous technologies, including the development of aqueducts and qanats. These water-based technologies allowed areas that were relatively dry to be more easily irrigated through major irrigation works. Iron was also more prevalent than other metals, which meant that many societies were able to benefit from this development. Large forested areas were cleared, terracing became easier, and fuel needed for iron making and other operations were more easily gathered as wood could be cut easier. In effect, the stage was set for new areas to be settled and for infrastructure expansion, including water provisioning, that allowed cities to grow.

Figure 1. Iron helmet; the production of iron transformed warfare.

Later Developments

While steel was already around soon after iron working developed, it took some time before mastering the technology improved. The Romans mastered using coal, rather than wood, for fuel in furnaces. This gave them a new fuel source to produce better quality iron and steel. However, this practice did not become widespread and may not have been extensively used after the Romans in Europe. New steel production techniques from China and India, which developed by the 5th century CE, did, however, spread to other areas of the Old World. This included mixing wrought and cast iron together to form a stronger weapon/tool. The so-called Bessemer method, which is a modern steel production technique and developed much later, already had a precursor developed in China by the 11th century CE (Figure 2). This included repeated cooling and reforging the steel into a stronger product. Problems of having relatively brittle iron were now effectively being solved. Previously, the quality of the iron ore affected the quality of weapons and tools. Now, new production techniques that enabled carbonized iron to be more easily made, and thus creating steel, allowed more rapid spread of better weapons and tools. In the Medieval Islamic world, blast furnaces were developed by the 10-11th centuries. These allowed more industrial production and better production of iron. A process that utilized integration of carbides, through a crucible smelting process, produced some of the strongest steel in the Medieval world. This was the so-called Damascus steel, produced in Syria, that produced some of the best quality swords and weapons of the Medieval world.

Europe was largely behind much of the Old World in the quality of steel production in the Medieval period. Things began to change in the early 17th century. A method that cemented iron bars with carbon, the so-called cementation processes. This method was soon utilized in blast furnaces that began to produce better quality steel. Similar to what happened in much of the Old World, dependence on wood led to an eventual limitation of steel production. This created the need, similar to what was seen in China, for the use of new fuels. By the early 1700s, the use of coke was now utilized in creating steel. This removed the need for wood, as coal could now be used, a supply that was plentiful. The use of coke also gave the carbon needed to produce better quality steel.

In the 19th century, improvements in blast furnaces, invented by James Beaumont Neilson from Scotland, enabled much cheaper steel to be made. The Bessemer process was soon developed by the 1850s, by Henry Bessemer, which enabled the production of steel to not only be relatively cheaper, but it allowed it to be done more quickly at an industrial scale. Within a half hour, nearly 25 tons of pig iron could be converted to steel. Other forms of steel developed, such as alloy steels that gave greater flexibility to steel. Stainless steel was developed by the early 20th century.

Figure 2. Chinese steel production was advanced and foreshadowed modern methods.

Deep Impact of Ferrous Technologies

Earlier developments in iron allowed many changes to occur, such as the growth of irrigation works and cities. New lands were put into agricultural production thanks to the development of iron and steel. However, one major limitation had been the cost of steel production. This only changed by the 1850s, when steel production, using the Bessemer method and other developed steel technologies in the 19th century, allowed the so-called second wave of the Industrial Revolution that took place in the late half of the 19th century.

With the cheaper production of steel, and new alloys developed, steel now was utilized for making railroads more widespread, the telegraph became more prevalent, and steam furnaces also became common. All of these technologies were already developed by the early 19th century; however, none of them were widespread until steel production became cheaper in the second half of the 19th century. Another innovation was that steel could now be used for building production more commonly. This allowed much stronger structures to be built without using too many bricks or cement. In effect, buildings could become lighter. This now allowed, by the late 19th century, the development of taller buildings. The Home Insurance Building in Chicago, opening in 1884, became known as the world's first skyscraper at 10 stories. While earlier iron technologies allowed for more agricultural production, the new steel technologies widely present by the 19th century allowed cities to grow much faster and upwards through cheaper production of steel. By the 1890s, steel led the way in tall building construction, where Chicago now had 20 skyscrapers that were 16-20 stories tall by this time.

Steel also allowed the widespread production of cooking pots and other household items to be cheap, allowing mass consumerism to take place. New appliances, ranging from refrigerators to kitchen items, now incorporated steel. Larger objects, such as ships and trains, could also be made from steel more easily, allowing a revolution in transportation. With developments in communication and transportation using steel, the modern world was now developing that also fueled the expansion of states such as the United Kingdom, Germany, France, and the United States. Steel helped to power states of the early 20th century, where the greater political and military powers were fueled by steel production, including battleships and other weapons, helping to lead to the tensions that ultimately created World War I and World War II. One can argue, therefore, that modern steel production also led to the key conflicts of the 20th century that have politically shaped our modern world.

Summary

Ferrous technologies are easily seen as one of the greatest impacts on the ancient and modern worlds. Our modern lives of mass transport and communication would not have been possible without it. The technologies also allowed new areas to be put into production and ultimately allowed our cities to grow upwards and outwards. Ferrous technologies have not only influenced our societies' developments but also allowed the development of modern conflicts that have politically shaped the globe, including major alliances and modern state boundaries.