1. Lost Technology 2014131021 Takamitsu Sakai

2. What is Lost Technology ？  It is the technology that has been lost by some kind of reasons in the present age  out-of-place-artifacts Crystal skeleton → There is the opinion it is the imitation.

3. Factor of the outbreak  A successor disappears, and a technique is lost.  The base of the technique disappear by an environmental change.  By development of different technology, it decline.

4. Old Japanese sword  "An old Japanese sword" means swords from the Heian era to the Sengoku era.

5. Mystery of the old Japanese sword  How do it was made ？

6. History of the Japanese sword

7. Damascus steel ← Indian dagger using the Damasucus steel

8. Mystery of the Damascus steel  How do it was made ？  Why is it hard to be rusted ？ “Pillar of Delhi” in India This is said to be made of Damascus steel

9. The other Lost Technology ← Greek fire Roman aqueduct →

10. Reference materials  http://ohmura-study.net/003.html  http://www.nittech.co.jp/M99/M9906.html  http://ja.wikipedia.org/wiki/%E3%82%AE%E3%83%AA%E3%82%B7%E3%82%A 2%E7%81%AB%E8%96%AC