• il y a 4 jours
Transcription
00:00Obviously, the ore had to be removed from the ground. So, whether it was found right on the surface or had to be mined, the first step was...
00:08Digging!
00:09Yes, digging.
00:17The ore was often found in more or less inconvenient places, so the next thing to be done was...
00:23Hauling?
00:24That's right, hauling.
00:30The next step, a most important one, was...
00:33Smelting!
00:34That's correct, smelting. Getting the iron out of the ore.
00:39For this, a large furnace, often made of stone, was necessary.
00:43There had to be huge bellows to blast air through and make the fire hotter.
00:47And there also had to be...
00:49Charcoal and limestone!
00:51Correct. Charcoal and limestone.
00:54The charcoal was fuel for the fire.
00:56And while our friend here didn't know it, it also furnished carbon for chemical reactions that helped free the iron in the ore.
01:03The limestone was put in because it could be used as a fuel for the fire.
01:07The charcoal was fuel for the fire.
01:09And while our friend here didn't know it, it also furnished carbon for chemical reactions that helped free the iron in the ore.
01:16The limestone was put in because it soaked up impurities, forming a slag which could be discarded.
01:21The smelting process was begun by dumping layers of ore, limestone and charcoal into the furnace...
01:28Into the furnace!
01:37And while our friend here didn't know it, it also furnished carbon for chemical reactions that helped free the iron in the ore.
01:45The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
01:51The smelting process was begun by dumping layers of ore, limestone and charcoal into the furnace...
01:57Into the furnace!
01:59And while our friend here didn't know it, it also furnished carbon for chemical reactions that helped free the iron in the ore.
02:06The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
02:13The smelting process was begun by dumping layers of ore, limestone and charcoal into the furnace.
02:20The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
02:27The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
02:34And while our friend here didn't know it, it also furnished carbon for chemical reactions that helped free the iron in the ore.
02:42The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
02:49The charcoal was put in because it soaked up impurities, forming a slag which could be discarded.
02:56Putting the soft iron in clay pots, adding a certain amount of charcoal or other carbon, and making his fire hot enough to melt the iron.
03:06Getting enough heat was difficult, but this was the secret of the process.
03:11The iron he obtained this way was very special, for it combined the best qualities of the others.
03:17It was even given a special name, steel.
03:22It could be shaped by hand. It was supple and flexible and would not shatter.
03:30Yet it was hard and tough and would stand up under difficult conditions.
03:35But because it could be made only in small quantities, steel was rare and precious, worth its weight.

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