text: Ceramography evolved along with other branches of materialography and ceramic engineering.  Alois de Widmanstätten of Austria etched a meteorite in 1808 to reveal proeutectoid ferrite bands that grew on prior austenite grain boundaries.  Geologist Henry Clifton Sorby, the "father of metallography," applied petrographic techniques to the steel industry in the 1860s in Sheffield, England.  French geologist Auguste Michel-Lévy devised a chart that correlated the optical properties of minerals to their transmitted color and thickness in the 1880s.  Swedish metallurgist J.A. Brinell invented the first quantitative hardness scale in 1900.  Smith and Sandland developed the first microindentation hardness test at Vickers Ltd. in London in 1922.  Swiss-born microscopist A.I. Buehler started the first metallographic equipment manufacturer near Chicago in 1936.  Frederick Knoop and colleagues at the National Bureau of Standards developed a less-penetrating (than Vickers) microindentation test in 1939.  Struers A/S of Copenhagen introduced the electrolytic polisher to metallography in 1943.  George Kehl of Columbia University wrote a book that was considered the bible of materialography until the 1980s.  Kehl co-founded a group within the Atomic Energy Commission that became the  International Metallographic Society in 1967.