I would have thought that with bronze being an alloy it would have been more difficult to work with than iron, so why was it the first to become widely used?
In: 2489
I read somewhere a theory that the bronze age did not necessarily precede the iron age, but that both technologies overlapped and were developed at different rates in different places. The iron artefacts were less likely to survive.
Examples: Tutankhamun (bronze age king) had a meteorite iron dagger in his burial goods & the Inuit (no bronze) had iron tools made from meteorite boulders that Peary later nicked.
Besides that, the working methods are very different. Bronze, melt & pour.
Iron, heat white hot, batter the bloom to remove slag. Repeat, repeat, repeat, to make wrought iron. Crucible steel came much later. They weren’t melting iron until much later.
The trading of tin and copper across thousands of kilometers and dozens of independent political entities was a bigger deal than the copper.
**First, Availability**
Copper is easier to find as a metal, while natural metallic iron is only found in one or two places on earth or falls from the sky. In those places you find the occasional group that skipped the bronze age entirely and use/used knapped iron tools. Iron tends to be found only in compounds in rocks or sand, not as metal, and the entire rock or loads of sand need to be melted down to only produce a small amount of bad iron.
**Second, Ease of Use**
Copper based metals are easier to work with in general.
If you melt and cast bronze, you can get a workable tool out of it. It’s also fairly corrosion resistant and can be recast as needed.
If you melt and cast iron, you get cast iron which is not suitable for a lot of tasks. It’s brittle, it rusts, and it’s not very strong.
If you melt and cast good bronze, you get good bronze. if you melt and cast good iron, you get crap iron.
Iron has to be worked and have more of the inclusions removed via higher temperatures and physical working of the hot metal. Once you’ve got the process for it though, you get a stronger and tougher metal than bronze.
One thing you have to understand is the lengths of time we’re talking about here. The Stone Age lasted over a million years, while humans gathered information excruciatingly slowly, and began to spread it amongst themselves. At some point during that tremendous amount of time, humans must have thrown some rocks into their fireplaces, whether it have been to warm them up to then throw into soups to keep them hot longer, or to potentially cover the flames and create hot coals for ritual purposes.
Regardless, eventually they found that certain rocks would leave hard “puddles” of a different, more easily shapeable “rock.” They took notice of how this could be useful, as currently their tools all relied on finding stones of the right shape and then laboriously shaping them down, and began to experiment with it. By the onset of the Bronze Age, we had more or less completely figured out how to determine which rocks would produce a puddle and how to get the most puddle out of any given rock. We also figured out what the puddles could be useful for once they hardened in certain shapes and were filed down like they used to do with their stone tools.
However, to get to Bronze from simple metals like copper or tin, obviously you need to make an alloy. How did that happen? Well, it was already clear that most liquids could be mixed, and by now, we noticed the puddles were liquid. Maybe a tool-maker used two different kinds of ores due to not having enough of one for his needs. Maybe it was part of a deliberate experimental process to figure out how to maximise efficiency of toolmaking. Maybe someone wanted to see what would happen if you mixed something into the puddle, like that weird red gem-looking dust you got while digging (arsenic-sulphur), and let it harden? Regardless of the process, you end up with this new puddle which seems harder and stronger than either of your old puddles. With a little more tweaking to find the best ratio of materials, you finally make Bronze, becoming the greatest toolmaker in the world overnight. This obviously doesn’t last, as this occurs all over the place, especially once people realise it’s possible.
However, this whole time, many metallic rocks were being thrown aside as they couldn’t be melted with the current temperature flame. Maybe later on, when people were trying to ~~improve~~work around bronze, they realised that iron was still harder than ~~bronze~~copper was, so they focused on finding ways to make it workable. Maybe they were already improving how hot their flames were, and began to notice that it was possible to work with more metals when they had hotter flames, and the finding was a coincidence. Another theory suggests that iron arsenide was deliberately made as a copper smelting byproduct so that the arsenic could be recycled into bronze, and blacksmiths experimented with the leftover iron slag. Regardless, without working with copper and bronze as extensively as they had, there would have been no reason for them master fire to such an extent, which made working iron possible in the first place. Going through the Bronze Age and completely mastering low-melting-point metals over a couple thousand years was essential for entering the Iron Age and working with harder, higher melting-point metals.
Stone Age lasted over a million years. Bronze Age lasted over 2000 years. Iron Age was not even 1000 years. Each era is a natural evolution of the previous era due to making use of the best technology available at the time.
I’m surprised no one has mentioned one of reddit’s favorites, [Primitive Technology](https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA).
If you follow him from the beginning you can watch his journey from making basic stone age fires to ‘advanced’ iron smelting from the iron age.
this article is really amazing and explains a lot why copper, then bronze, then iron:
[https://www.tf.uni-kiel.de/matwis/amat/def_en/kap_5/advanced/t5_1_4.html](https://www.tf.uni-kiel.de/matwis/amat/def_en/kap_5/advanced/t5_1_4.html)
i got lost for days reading all the links
It’s worth pointing out that a Bronze Age doesn’t always happen before an Iron Age. In most places that has been the case, but not in West and Central Africa. Cultures like the Nok smelted iron before they smelted copper, and so went straight from the Stone Age to the Iron Age.
Note though that the history of early metallurgy in Africa is still poorly understood, and there is still a lively debate about if ironworking was discovered independently in Africa or if the knowledge was imported somehow.
But at any rate the progression from Stone to Bronze to Iron should not be taken as the only possible path even if it’s the “easiest” and thus most common.
Bronze can be melted and cast easily to make strong and durable tools and weapons; however when you cast iron, the process burns all the inherent carbon content in iron and and makes pure iron too soft to be useful. Iron needs to smelted which is a delicate and complicated process to get more carbon in itself and become harder and more durable than bronze. Also even you sucessfully introduced carbon to iron with smelting, iron still needs to go through forging and the heat treatment (another very complicated and delicate process) to finally become useful as a tool/weapon. In contrast to all those, you can cast a bronze tool in an open stone mould, wait it to cool down, polish it(or not), (maybe cold hammer the edges a little to toughen it) and start using it immediately. And bronze tools are very durable and when bent or damaged so easily fixable, unlike the britleness of early low carbon steel/iron that had many impurities within. Not to mention bronze dont really rust, and can be remelted and recast over and over again.
Copper and tin both have lower melting points than iron. Bronze itself has a melting point some 500°C lower than wrought iron. This makes it much easier to cast and work than iron based alloys if you don’t have access to good quality furnaces.
Iron in it’s more useful forms is also technically a blend of iron and carbon. So you need to be able to produce large amounts of charcoal if you want to produce large amounts of strong iron and steel. This requires large amount of lumber, not something easily accessed without metal tools.
Iron, because of the aforementioned melting point and need for carbon additives, varied wildly in quality across the ancient world. In parts of the world that had access to comparitively low quality iron deposits or furnaces or even just limited lumber resources, like Japan, Scandinavia or the Middle East, we saw the development of forging techniques like “folding” to compensate for the impurities in the ore. Folding is a labour intensive process where one heats iron bars, hammers them out, folds them over, and hammers them out again. This folding strengthens the final iron bar and is useful for sword forging. Katanas are famously folded hundreds of times. Damascus Steel is another example. However, because of the labour and time involved, this is a highly specialized process that requires pretty hefty investment in tools and learning before it could become widespread.
Technology does not always get developed in the order you expect. The right genius with the right resources diligently working on solving a problem can result in amazing developments seemingly out of intuitive order.
As an example, consider the fact that humankind invented nuclear weapons (1940’s) before inventing compound bows (1966). This doesn’t make sense if all sophisticated tech necessarily has to be developed after simple tech. For that reason, bronze alloys being more difficult than iron alloys (if that is actually true) has no bearing on whether or not the simpler one gets developed first.
Imagine the ancient world’s equivalent of Nicola Tesla, some extremely prolific genius working in the highest tech of their day, metalurgy. If he happens to have access to copper or copper ore and tin, but not iron ore, given years of his hard work, experimentation, and tinkering, he might come up with sophisticated bronze alloys but not come up with anything based on iron simply because of lack of access to the right ore. And vice versa.
The Assyrians, for example, built their empire using iron weapons, but the Greeks who came after them were still largely bronze-based, if I remember correctly.
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