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February 2008 Blast Furnace Stee-makingl, Tatara furnace iron-making, and Princess Mononoke

I am not sure where I learned the word “step on Tatara furnace,” but somehow it sounds mysterious in my memory.Originally a technical term, if you look it up in a Japanese dictionary, it will come out as a word in everyday life.Recently, it seems that demand for steel-related products has been expanding, and I often hear related news such as new blast furnace firing ceremonies at various steelworks, and restoration of long-used blast furnaces.In a recent newspaper article, Sumitomo Metals had a plan to build a new steel mills in Brazil.In the current blast furnace, coke is introduced as a reducing material together with iron ore.In this Brazilian steel mill, they will cultivate eucalyptus plants, using the vast land, then use the charcoal made of them instead of coke.Then, carbon dioxide absorbed by eucalyptus and carbon dioxide emitted from the blast furnace can be offset.It's quite a big-scaled story.

I lived in Hiroshima for over 10 years before coming to the Kyoto College of Graduate Studies for Informatics.In the Chugoku Mountains centering on the border between Hiroshima and Shimane Prefectures, there are many traces of Tatara furnace for iron-making from ancient Japan.Last summer, a person familiar with the local history took me on a tour of the northern part of Hiroshima Prefecture, and we were able to actually check it out.It seems that the sand iron available in the Chugoku Mountains, and charcoal from the surrounding mountain timber were significant.I have a feeling that this charcoal story is somehow connected to the charcoal from the eucalyptus plantation.In any case, Tatara furnace iron-making is a technology that has been handed down over 1000 years since ancient times in Japan.

When I was thinking about this, Miyazaki Hayao's “Princess Mononoke” came to my mind.There is a scene where Eboshi Gozen is actually stepping on the tatara furnace in the iron mill.Tatara stepping furnace is a device that puts iron sand and charcoal in a furnace and sends air into it with a huge bellows.If you look at this scene, you can see that many people put their weight on the board of the big bellows and pump in the air.Moreover, if you don't keep stepping on it, the fire in the furnace will be extinguished.What Hayao Miyazaki had in mind when he drew the scene is not known, but it may be related to the relationship between people and nature, which can be also linked to the planting of eucalyptus trees.

Technology changes rapidly as the time goes by.Nowadays, it seems that Tatara furnace iron-making is only used for special events or for making special Japanese swords.However, it should be recognized that Japan has a culture that has handed down such technologies since ancient timesThere are many technologies that are replaced by the newer technologies and disappear, but even so, new ones will be born on top of the accumulation of the old.Shouldn’t we occasionally reflect on the fact that Japan has a long history, in many aspect, that can lead to such accumulated knowledge.

Keiichi Yamagata