A researcher and curator at the Intermediatheque of The University Museum of the University of Tokyo, Kei Osawa has extensively worked on the Japanese physicist and meteorologist Masanao Abe, the author of a series of cloud studies during the 1920s and 1930s using photographs, films, as well as a wind machine of his own design. The work of Masanao Abe is here discussed in relation to a long, Western tradition of cloud studies that moves from Luke Howard’s Essay on the Modification of Clouds (1803) to Alfred Stieglitz’s Equivalents (1925-1934).