The furo and the ro are rarely, if ever, used together, however there are so many similarities and differences that examining them together is quite revealing. One great difference is that the furo/kama manifests the Yō, 陽, positive aspect, and the ro manifests the In, 陰, negative aspect.  The standard fu-ro, 風炉, wind-hearth, that uses a go-toku, 五徳, five-virtues, to support the kama, 釜, kettle, was originally made of tetsu, 鉄, iron, as was the kama, 釜, kettle. Furo are made in various materials; iron, bronze, ceramic, wood, etc. A furo is essentially a large bowl that has an opening in the front, hi–mado, 火窓, fire-window. The...