A fireplace is a common feature in many homes, and it is composed of several parts. The HOB, or HEARTH opening border, is the frame around the opening of the fireplace. The FLUE is the duct that carries smoke and combustion gases up and out of the house. The MANTEL is the shelf above the fireplace. The GRATE is the metal frame that holds the burning fuel. The HEARTH is the floor of the fireplace, usually made of brick or stone. ANDIRONS are metal supports that hold logs in the fireplace. The JAMB is the vertical side of the fireplace opening. Finally, the SMOKEDOME is a metal cover that fits over the top of the fireplace to prevent sparks from escaping.