Water for making tea is heated in a kettle that is heated over a charcoal fire set in a hearth. The hearth was a standard open square in the floor called an i-ro-ri, 囲炉裏, surround-heart-inner, filled with ash and various implement to support different vessels, which were also hung above the fire. In Chanoyu, the hearth was called a fu-ro, 風炉, wind-hearth.    The earliest form of kama was supported directly on the furo. The kama of the Ki-men-bu-ro, 鬼面風炉, Demon-face-wind-hearth, has a quarter-round flange called a hane, 羽, wing, sits on the furo atop an upright perforated collar called a koshiki, 甑, ring support. Such furo...