View Full Version : How did the Bronze Age start?


Onionsoilder
Feb 21, 2010, 11:42 AM
Sort of a shot in the dark here, but does anyone know how ancient civilizatiosn first discovered copper, and then bronze? How did they know that the ores were different from normal rocks? How did they know to make alloys and such?

innonimatu
Feb 21, 2010, 11:55 AM
Sort of a shot in the dark here, but does anyone know how ancient civilizatiosn first discovered copper, and then bronze? How did they know that the ores were different from normal rocks? How did they know to make alloys and such?

Well, the first metals to be worked were those with a low fusion point. One theory I read was that the discovery might have been accidental, after lighting camp fires on top of easily reduced metal oxides. That might apply to lead and other metals with low melting points, but not to copper or iron.

Check this page (http://neon.mems.cmu.edu/cramb/Processing/history.html).

Onionsoilder
Feb 22, 2010, 06:02 PM
Hmm... looks like native gold was the first metal discovered, just from small nuggets found in rivers and such. Probably found copper nuggets too, though they would have been less noticeable than gold...

JEELEN
Feb 22, 2010, 10:35 PM
Sort of a shot in the dark here, but does anyone know how ancient civilizatiosn first discovered copper, and then bronze? How did they know that the ores were different from normal rocks? How did they know to make alloys and such?

Bronze is not found, it's an alloy, forged by the use of copper, which can be found. (The isle of Cyprus is named after it: kypros/kupros = copper in Greek.)

Lord Baal
Feb 23, 2010, 02:10 AM
Bronze is not found, it's an alloy, forged by the use of copper, which can be found. (The isle of Cyprus is named after it: kypros/kupros = copper in Greek.)
Copper and tin, both of which can be found. I've heard a theory that the Iron Age actually started because tin supplies were running low, forcing smiths to experiment with different metals and alloys.

North King
Feb 23, 2010, 04:53 PM
Yeah, copper (and even some other metals, IIRC) could be found in nugget form on or near the earth's surface. Typically these have already been picked up and made into things by the time you or I walk across the land. And anyone who leaves metal unattended in a fire will notice it starting to glow; add in natural human curiosity and you'll realize it's soft, too. It then probably pretty naturally proceeds to melting, smelting, and alloying.

Copper and tin, both of which can be found. I've heard a theory that the Iron Age actually started because tin supplies were running low, forcing smiths to experiment with different metals and alloys.

Most civilizations in the "Near East" underwent a dark age/collapse period within a very short span of time. This "Bronze Age collapse" has been attributed to tin shortages (by some, anyway).

sydhe
Feb 23, 2010, 10:27 PM
Bronze was initially made with arsenic, probably because some copper ores naturally contain arsenic. This was abandoned when it was discovered bronze could also be made with tin because metal workers who used tin were a lot more likely to survive.

warpus
Feb 23, 2010, 11:54 PM
What can bronze do that copper by itself can't? (yeah, this probably sounds like a stupid question to some of you, but I really have no idea)

and how did people figure out to start mixing stuff to eventually end up with bronze, anyway?

aelf
Feb 24, 2010, 12:05 AM
Copper is too soft. It's pretty good as a conductor, but it's not suitable for heavy duty purposes.

JEELEN
Feb 24, 2010, 12:08 AM
Metallurgy - which allows for alloys, so the develpment of kilns that produce and sustain enough heat for forging would have been essential. Bronze is suitable for weaponmaking, copper is too brittle in comparison. I assume, as with most inventions, experimentation would have been vital to the discovery of bronze as an alloy. (Monkeys, notably chimpansees, use sticks and stones to frighten off and/or kill enemies - and as tools. It would seem humans have learned to adapt these tools in highly innovative ways; but the discovery of making fire seems a vital development, both here and in general.)

Dragonlord
Feb 24, 2010, 02:44 AM
Bronze is suitable for weaponmaking, copper is too brittle in comparison.

Copper is brittle? Surely not - it is soft and malleable, the very opposite of brittle, as I understand the word. Copper is too soft and won't hold an edge, that is why bronze is more suitable for weaponmaking.

BTW, the usual perception is that iron weapons were superior to bronze - I've read that, on the contrary, early iron weapons, at least, weren't as good as high-quality bronze. Iron came to be preferred only because it was cheaper and more plentiful, due to the scarcity of tin.
Anyone know the truth of this?

holy king
Feb 24, 2010, 02:56 AM
that may hold true for very low quality iron, but generally iron is harder than copper.

Dragonlord
Feb 24, 2010, 03:26 AM
that may hold true for very low quality iron, but generally iron is harder than copper.

Than copper? Of course - but I was talking about bronze, which is much harder than copper alone.

Also, hardness is not the only quality for weapons - a hard but brittle iron weapon that shatters at the first stroke would also be worthless.

BananaLee
Feb 24, 2010, 03:40 AM
If I recall right, pure iron is pretty ductile and rubbish in terms of hardness compared to bronze. However, wrought iron (in the west) and cast iron (in the east - I'm using these terms VERY loosely here) are definitely harder than bronze. Not to mention cheaper.

Dragonlord
Feb 24, 2010, 08:21 AM
If I recall right, pure iron is pretty ductile and rubbish in terms of hardness compared to bronze. However, wrought iron (in the west) and cast iron (in the east - I'm using these terms VERY loosely here) are definitely harder than bronze. Not to mention cheaper.

Cheaper, yes. That's my point.

What I read is that early iron weapons weren't necessarily better than bronze (we're not talking about steel here), just infinitely cheaper once the basic problems of iron smelting were solved.
I too had always thought iron weapons were intrinsically better - thinking when an iron sword met a bronze sword, the latter would be cut - but I'm no longer so sure.

ParkCungHee
Feb 24, 2010, 08:25 AM
I think it's relavent to discuss what the quality of ironworking we're talking about. Initial Iron Working was likely rubbish, but late ironworking?

Onionsoilder
Feb 24, 2010, 09:18 AM
Bronze is not found, it's an alloy, forged by the use of copper, which can be found. (The isle of Cyprus is named after it: kypros/kupros = copper in Greek.)
I didn't mean finding bronze nuggets on the ground, I meant how did early civilization know to combine copper with tin to make bronze?

Tabster
Feb 24, 2010, 10:58 AM
I meant how did early civilization know to combine copper with tin to make bronze?

They may have just been trying to make larger pieces of metal in general, by combining smaller lumps of metal, mostly copper but also some happened to be tin, and accidently made bronze, I doubt that they were actually trying to make an new alloy by combining two types of known metal.

The fact that this combination produced a metal with very different qualities to either copper or tin, I would imagine, come as a great surprise as the only other alloy they knew of, electrum (gold and silver) has very similar qualities to both silver and gold.

BananaLee
Feb 24, 2010, 11:52 AM
What I read is that early iron weapons weren't necessarily better than bronze (we're not talking about steel here),

I too had always thought iron weapons were intrinsically better - thinking when an iron sword met a bronze sword, the latter would be cut - but I'm no longer so sure.

Okay, my engineer hat is coming on here. The common term "iron" usually refers to wrought iron, which itself is a very low-carbon form of steel. I don't think any tools are made of pure iron.

Having said that, I'm quite sure once they got their act together, when the smelting, etc. provided consistent properties to the iron (as opposed to pockets of air and that sort of thing all over the finished product) and they learned how to smash it with a hammer properly (allowing consistent work-hardening), wrought iron tools were definitely harder, and kept its edge better.

Iron swords would not cut bronze swords under any reasonable circumstance.

Tabster
Feb 24, 2010, 02:09 PM
What I read is that early iron weapons weren't necessarily better than bronze (we're not talking about steel here), just infinitely cheaper once the basic problems of iron smelting were solved.

The very first iron/steel weapons would have likely have been made from meteorite iron, not iron smelted from ore, and would perhaps be somekind of iron/nickel alloy which are generally now referred to as 'nickelsteels'. Some of this meteorite iron could, depending on the actual composition, be tempered unlike wrought iron. Swords made from iron/nickle from these source, if correctly worked, would appear to vastly superior than either bronze or wrought iron swords.

Bronze alloys can have different properties dependent on the proportion of tin to copper. 'Weapons grade bronze' would need a high ratio of tin to copper to supply the hardness to the alloy.

Cutlass
Feb 25, 2010, 08:28 AM
Cheaper, yes. That's my point.

What I read is that early iron weapons weren't necessarily better than bronze (we're not talking about steel here), just infinitely cheaper once the basic problems of iron smelting were solved.
I too had always thought iron weapons were intrinsically better - thinking when an iron sword met a bronze sword, the latter would be cut - but I'm no longer so sure.

Swords don't really cut one another. Mostly they batter the edge dull and possibly chip it a bit. If one sword is very brittle, than a chip can lead to a crack to a full break. Swords don't really cut armor either. Not with just human strength behind them.

North King
Feb 25, 2010, 01:44 PM
Copper is brittle? Surely not - it is soft and malleable, the very opposite of brittle, as I understand the word. Copper is too soft and won't hold an edge, that is why bronze is more suitable for weaponmaking.

Copper is the malleable one of the pair, tin the brittle.

BTW, the usual perception is that iron weapons were superior to bronze - I've read that, on the contrary, early iron weapons, at least, weren't as good as high-quality bronze. Iron came to be preferred only because it was cheaper and more plentiful, due to the scarcity of tin.
Anyone know the truth of this?

Correct in some respects. Iron can hold an edge much better, making it more useful for certain weapons, but I'm pretty sure bronze was more useful in respects where tensile strength was required. Hence cannons, until high quality steel became cheap, were more effective when cast from bronze than iron -- the latter had a tendency to burst. But bronze swords rather sucked.

Masada
Feb 25, 2010, 04:31 PM
Copper is brittle? Surely not - it is soft and malleable, the very opposite of brittle, as I understand the word. Copper is too soft and won't hold an edge, that is why bronze is more suitable for weaponmaking.

Correct. Bronze is brittle, it shatters surprisingly easily if you smack it hard enough against iron, for instance. However, bronze holds a better edge than copper because of its relative hardness, which also causes it to be brittle.

I too had always thought iron weapons were intrinsically better - thinking when an iron sword met a bronze sword, the latter would be cut - but I'm no longer so sure.

You adopt a totally different form of fighting with the two. Iron is suitable for being smacked against iron for a substantial period without shattering. You can therefore adopt a style of fighting that involves more cutting which is easier to learn and allows you to use substantially more power. Bronze is better suited for thrusting which doesn't run the same risk of shattering the blade, that said, I doubt the incidence of thrusting was substantially higher it was probably easier to just pick up a discarded blade on the ground. You do notice the differences in construction after a while, iron can be relatively thinner and longer because of the reduced incidences of shattering while bronze swords tend to be shorter and thicker to mitigate against the same.

BananaLee
Feb 27, 2010, 01:34 AM
Correct in some respects. Iron can hold an edge much better, making it more useful for certain weapons, but I'm pretty sure bronze was more useful in respects where tensile strength was required. Hence cannons, until high quality steel became cheap, were more effective when cast from bronze than iron -- the latter had a tendency to burst.

It's not a question of tensile strength, but one of toughness. Cast iron tends to be ridiculously brittle (because it needs up to 4% carbon to be meltable), and would not be *tough* enough to handle the jerk stress of an explosion.

In addition, there is the problem of casting big iron blobs, uneven cooling and air bubbles would cause stress pockets and weak spots in an iron cannon. Bronze cannon didn't have the same problem mostly because the thermal properties of bronze (different rate of heat transfer, etc.) were more forgiving of contemporary casting method.

JEELEN
Feb 27, 2010, 04:40 AM
I didn't mean finding bronze nuggets on the ground, I meant how did early civilization know to combine copper with tin to make bronze?

And I think that's been answered.

Atticus
Feb 28, 2010, 05:57 AM
About the cheapness of iron, I remember reading that Hittites made good money by selling iron to Egyptians. Egyptians had plenty of gold, but not much iron or knowledge how to produce it. As a result they considered iron valuable beyond it's practical uses, and for example iron rings have been found in tombs of Pharaos.

However this was probably when iron was meteorite-iron, and I might remember the whole thing wrong.

Lord Baal
Feb 28, 2010, 06:04 AM
I do know that iron was originally used in make-up, then in jewellery, before its practical uses became known.

ParkCungHee
Feb 28, 2010, 10:39 AM
About the cheapness of iron, I remember reading that Hittites made good money by selling iron to Egyptians. Egyptians had plenty of gold, but not much iron or knowledge how to produce it. As a result they considered iron valuable beyond it's practical uses, and for example iron rings have been found in tombs of Pharaos.

However this was probably when iron was meteorite-iron, and I might remember the whole thing wrong.
Well, everything is rare and valuable if you dont know how to make it.

Lord Baal
Feb 28, 2010, 07:56 PM
Well, everything is rare and valuable if you dont know how to make it.
No wonder I find love so rare and valuable. Wait, what?

North King
Mar 03, 2010, 11:32 AM
It's not a question of tensile strength, but one of toughness. Cast iron tends to be ridiculously brittle (because it needs up to 4% carbon to be meltable), and would not be *tough* enough to handle the jerk stress of an explosion.

In addition, there is the problem of casting big iron blobs, uneven cooling and air bubbles would cause stress pockets and weak spots in an iron cannon. Bronze cannon didn't have the same problem mostly because the thermal properties of bronze (different rate of heat transfer, etc.) were more forgiving of contemporary casting method.

Forgive me, engineering terminology is not something I'm familiar with.

Actually, do you have any recommendations for readable literature on the subject?

vogtmurr
Mar 03, 2010, 11:49 AM
Correct. Bronze is brittle, it shatters surprisingly easily if you smack it hard enough against iron, for instance. However, bronze holds a better edge than copper because of its relative hardness, which also causes it to be brittle.
.

Wrought iron is weaker than bronze, but because it was less expensive, and more easily sharpened, people used it anyway.

I believe bronze is considerably less brittle than iron, (and I mean wrought iron, not cast). That is why it is still used for things like springs. It is tough, but is softer and therefore incapable of holding an edge as well as good iron, or better yet steel. It is also far more corrosion resistant than most steels, has better heat conductivity, and has less metal on metal friction, which is why bronze cannon were highly desired in the early days, and why it is still used for things like bearings.

BananaLee
Mar 03, 2010, 12:17 PM
Forgive me, engineering terminology is not something I'm familiar with.

Actually, do you have any recommendations for readable literature on the subject?

Engineering School. :p
It really depends on what sort of level you're looking at, I picked up most of my things from coursebooks given in Eng School (i.e. they weren't textbooks), but try poking around for basic Mechanics of Materials or Materials Science books and you shouldn't be too far off.