Published online by Cambridge University Press: 26 January 2010
Johann Heinrich Lambert (1728–1777) developed a very detailed theory of science and experiment. Using Lambert's hygrometric studies, this article provides an introduction to Lambert's theory and its practice. Of special interest is his well-founded theory on the emergence and definition of concepts and his neat eye for heuristics that should ultimately lead to a mathematization of physical phenomena. His use of visualizations in this context is especially remarkable.