Gas pressure experiment. Despite a heavy weight (10 kilogramme mass) on the balloon, inflating it causes the weight to be lifted up. This is explained as a combination of the increased surface area between the plank and the balloon, and the evenly distributed force applied by gases. This illustration, part of a section titled 'Experiences de Physique sans Appareils' (illustrating popular physics experiments that don't require the use of laboratory equipment), is from 'Physique Populaire' (Emile Desbeaux, 1891).
Model release not required. Property release not required.