Siphon barometer mounted on a wooden base. A tap enables the longer arm of the siphon to be filled, preventing the mercury from moving during transport. The barometric scale is made of glass paste, as is the corresponding vernier. On the base are fixed two liquid thermometers, a mercury version with Réaumur and centigrade scales, and an alcohol version with Fahrenheit and centigrade scales. Made by Deleuil firm.