A glass flute or crystal flute is a glass instrument briefly popular in the early 19th century. They are an unusual variety of the Western concert flute designed to preserve pitch and tone during temperature change better than the wood and ivory flutes available at the time of their manufacture. Most were made by Claude Laurent, a French craftsman and clockmaker who patented the leaded crystal glass flute in 1806. They became obsolete after metal flutes were produced. Other than sounding more consistent at differing temperatures, glass flutes are similar in tone to contemporary wooden and ivory flutes.