This object, although it differs from the models proposed in 18th  century treatises, serves to illustrate an effect of atmospheric pressure.
On one side of the metal cylinder is a sort of handle, with a small hole at the end, and at the bottom on the other side there is a narrower cylinder with 3 small holes.
When the lower part of the object is immersed in water, it enters through the three holes in the base. The water does not come out of these if the hole in the handle is then plugged, and can be transported and poured into another container.
If the atmospheric pressure acting through the three holes is not balanced by that acting through the hole in the handle, it prevents the water from escaping.
Device on display.