The Goethe Table Barometer consists of a partly filled glass sphere with stand that has a spout attached to its base. The spout is open at the top, which allows the atmospheric pressure to change the level of the liquid inside. If the pressure rises, the liquid is forced back into the sphere against the internal air pressure and the level of the liquid inside the spout drops: fair weather is to be expected. When the atmospheric pressure drops, the level in the spout rises and predicts rain or storm.
Each purchase includes a syringe and tube for easy filling of the barometer and blue food dye. Please note the barometer is made from thin glass and children should only handle it under adult supervision.