the use of briar wood, beginning in the early 1820s, greatly reduced demand for clay pipes and, to a lesser degree, meerschaum pipes. the qualities of meerschaum were combined with those of briar pipes by lining briar pipes with meerschaum bowls. some smokers believe that meerschaum-lined briar pipes give the porosity and sweet-smoking qualities of meerschaum along with the heat-absorbing qualities and durability of briar. however, meerschaum must be cool before a pipe can be cleaned, and briar must be rested after a few days of smoking, so the combination comes with some of the drawbacks of both materials. the thinness of the lining can affect how long a pipe lasts and some smokers do not clean out their pipes, causing the meerschaum to crack.