Back to the Future: Returning Africa to the Technological Journey — Part 2
Let us ask the question again? How will Africa develop technology that removes the barriers that hinder social and economic development?
If you have not read Part 1, please do then come back.
Technological development through the ages brought and still brings social advancement. Tools are the one invention of Man that reveals his journey in technology and his dealings with his environment. Anthropologists and historians have divided the World into a number of technological “tools” ages. The Stone age, bronze and iron age.
During these ages, a lot of communicated World history revolves around the Europe, the Mediterranean region, India and China. One interesting fact was that the Americas do have a lot of natural occurring metals like gold and silver, that where melted and hammered into vessels and articles of honour. Very little has been found in utilitarian use. The environment was rich in these metals.
Africa, due to its oral nature, carried its history differently. For its size, very little of Africa’s history has been captured using “modern” documentation processes.
Nevertheless, it is important to note that technological innovation across the continents happened more or less at the same pace until very recently.
A Time: The Iron Age
Before the Iron Age, the Bronze Age span from 5500 B.C. to 1200 B.C. Populations in Ethiopia, Mesopotamia and Syrian regions used bronze as a major metal alloy to make tools and weapons. It is in the Aïr Mountains that are in north Niger where bronze technology was found but did not advance as much as in other areas in the world. Little is known of an Africa wide Bronze culture.
The Nok civilisation (1200 B.C.E. — 400 C.E.) existed in what is today’s northern Nigeria, large life-sized terracotta sculptures were found in alluvial tin mines. Tin is one of the main ingredients of bronze. This means that while the ingredients existed, bronze was not produced in this area. The Nok were already involved in iron smelting independently in the region prior to 1000 B.C.E. Interestingly the Nok went straight into the Iron Age around the time of the Late Bronze Age. This is about the same time that iron working was introduced in Europe, probably from the Caucasus mountains.
These known civilisations in the Iron Age were living independently from one another. In iron metallurgy, a process known as Bloomery was used across the world. Bloomery was found in Europe, West and South of the Sahara in Africa. They were also China and India from around 1200 B.C. From discoveries in Nuba (Sudan) and Axum (Ethiopia) bloomery was in full swing during 1000–500 B.C. Meroe, a city that was capital of the Kush kingdom, was known to have produced iron tools for the Nubians and the Kushites and traded the surplus. The Nilo-Hamites who came into East Africa have a clear iron culture that is visible in their ornaments and weapons.
In bloomery, a pit or chimney built of clay, which is heat resistant, is used. At the bottom, one or more pipes are used to allow air by natural draught or forced in with bellows. There are a number of steps taken before the bloomery. The first is that charcoal is prepared to produce the nearly pure carbon that is required. The second is the iron ore is broken or crushed into smaller pieces to remove any large impurities and to roast it, removing any moisture.
In operation, the bloomery is preheated by burning the charcoal. Once hot, the iron ore is introduced and it. The carbon monoxide produced by the partially combusted carbon removes the oxygen in the iron ore, leaving a metallic iron without melting the ore. So the red hot iron is desired since it is easily forgeable. The small quantities of iron produced in this fashion fall to the bottom of the bloomery, mixing with molten slag made of impurities in the ore. The product is a hard, spongy looking mass that is heated again and a hammer used to drive out the slag.
The Iron Innovation
Differences in the production process are clear when one studies the evolution on bloomery technology across the regions. All early bloomeries were relatively small, smelting quantities of about 1 kilogram.
In Europe, the growth of the populations required a higher output of iron for finding necessities and fighting wars. By the 1300s, bloomeries producing up to about 15 kilos have been found.
Two significant inventions changed bloomery. This is where the geographic environment makes a difference. In Europe, India and China, there are a large range of mountain ranges and seasonal deposits of snow that result in large flows of water to the sea.
The Water Wheel
The first invention was the water wheel that was placed in these abundant rivers. The water wheel was attached to bellows, allowing the bloomery to be larger and run hotter. The water wheel was also attached to hammers to produce wrought iron. This allowed the European bloomeries to reach a production size of 300 kilos. At this point, due to the size, the bloomery would get too hot producing liquid iron, which would cool and be unforgeable. To specifically produce molten iron, the Blast Furnace was developed.
In Africa, the metal workers did not make use of water power partly because sub-Saharan Africa has much less potential for water power. But Africa is flatter and relatively windy so the metal workers increased the size of their bloomeries by inventing a way to use natural air draught. These furnaces were particularly characteristic of the African Savannah woodlands, stretching from Senegal to western Sudan and southern Tanzania to northern Zimbabwe. They would build extremely high chimneys of up to 6.5 meters that allowed air to be pulled upwards naturally as the wind caused a drop in pressure in the chimney. This is exactly how termite mounds in the Southern hemisphere produce their “air conditioning”.
But in all these global regions, bloomery technology relied on charcoal that came from wood. It has been said the demise of iron production in the areas east of Senegal was due to the disappearance of the woodlands around them.
The second significant invention was the use of coke to fuel iron smelting happened in 1709. A man called Abraham Darby finally succeeded in smelting iron using coke as fuel in a Blast Furnace.
The Blast Furnace is one where the fuels, ore and limestone put in at the top of the furnace. The main objective unlike the bloomery is to smelt the iron and produce “pig iron”. This iron has a very high carbon content making it very brittle. It is intended for re-smelting for final iron or steel production.
Coke is produced by destructive distillation of coal, by heating coal anaerobically to very high temperatures, almost the same way that charcoal is made. This creates a very volatile carbon fuel with fewer impurities than coal.
In Africa, charcoal made from trees was a significant resource but it was not possible to produce at a large scale like in Europe really because there was no demand.
With the water wheel, blast furnace and with coke, the industrial revolution took off in full from the mid 1700s, starting off in Britain and moving to mainland Europe and North America and the rest of the world after that. In Africa, traditional iron production almost completely disappeared due to the arrival of cheaper iron from Europe.
Click here for Part 3.