The Austrian physicist Ludwig Eduard Boltzmann (1844-1906), educated at the University of Vienna, was appointed professor of mathematical physics at the University of Graz in 1869 at the age of only twenty-five. Boltzmann did important work in the fields of statistical mechanics and statistical thermodynamics; for instance, he contributed to the kinetic theory concerned with molecular speeds in gas. Boltzmann also promoted atomic theory, which at the time was still highly controversial. He was a member of the Imperial Austrian Academy of Sciences from 1885 and became a member of the Royal Swedish Academy of Sciences in 1888. This three-volume work, prepared in 1909 by the physicist Fritz Hasenöhrl, one of Boltzmann's students, comprises all his academic publications from 1865 to 1905. Volume 2 contains work from 1875 to 1881 on the thermal conduction of gases, the mechanic theory of heat and its problems, and the friction of gas.