The cloud chamber, a particle detector used for visualizing the passage of ionizing radiation, was originally developed by Scottish physicist Charles Thomson Rees Wilson with the goal of studying cloud formation and optical phenomena in moist air. His book Principles of Cloud Chamber Technique published in 1951 examines the potential of the cloud chamber as an instrument of precise measurement. It also reflects a keen scientific and historical interest in the post-war study of radiation. In Untitled, Pages of Wilson’s treatise are juxtaposed with cropped clouds, both the results of explosions and natural cloud formation.