What is Fukiya in Japanese Katana terminology?

Fukiya (踏鞴) refers to a bellows used to blow air into a furnace for ironmaking. It is an old term that is mentioned in the ""Nihon Shoki"" (The Chronicles of Japan), where it is used in the name of ""Himetataraisuzuhime no Mikoto"" (媛蹈鞴五十鈴姫命), who became the wife of ""Emperor Jinmu"" (神武天皇).

Later on, the term ""Tatara"" (鑪) came to be used to refer to the furnace used for refining iron. It then evolved to refer to the large house that contains the entire furnace, and even further to refer to the entire ironmaking factory including these elements.

In the context of ironmaking, the Fukiya is a crucial tool as it allows for the control of the temperature within the Tatara, which is essential for the refining process. The term ""Tatara"" itself has a rich history and is deeply ingrained in the tradition of Japanese ironmaking."