Fountain in Vacuo (Fountain in a Vacuum)
The fountain in a vacuum apparatus demonstrates atmospheric pressure on a liquid.
The air is evacuated from the tube, and the tap closed. The apparatus is then placed in a container of water.
If the tap is opened, the atmospheric pressure forces the water into the tube, giving the effect of a fountain.
Height 70cm. Circa 1860.
Fontaine dans le vide.