This topic includes information related to the design and construction of masonry fireplaces. Masonry fireplaces are constructed over a foundation that supports the fireplace structure above, which is built with masonry units, refractory masonry units, concrete and clay tile. During the late 18th century, Count Rumford designed a masonry fireplace that was better at drawing smoke out of a building than previous designs. His design, which incorporates clay flue liners, a smoke chamber, a damper and a throat over firebrick walls and hearth, is the foundation for modern masonry fireplaces.