Notice the hole on the side of the box. The is a 30 cm metal tube (O/ 4,5cm) which ends in the edge of the "sand-clay pot". The tube is used to blow air into the furnace.
Notice the hole on the side of the box. The is a 30 cm metal tube (O/ 4,5cm) which ends in the edge of the "sand-clay pot". The tube is used to blow air into the furnace.