Figure 12: Joseph Louis Gay-Lussac and Jean-Baptiste Biot ascend in balloon conducting scientific experiments

On August 24, 1804, Joseph Louis Gay-Lussac and Jean-Baptiste Biot ascended in a hot air balloon to a height of 4,000 meters altitude in order to conduct scientific experiments on gases. These experiments led to Gay-Lussac's discovery that equal volumes of all gases expand equally with the same increase in temperature. Coined "Charles' law," this discovery was named after Jacques Charles who conducted similar unpublished experiments fifteen years earlier.

This plate is from John Howard Appleton's (1844-1930) Chemistry, Developed by Facts and Principles Drawn Chiefly from the Non-Metals, published in 1884. Intended as an introduction to the study of chemistry, this volume contains illustrations throughout the text including color plates. Color plates have been digitized along with a selection of illustrations.