Royle's self-pouring teapot
Jearl Walker www.flyingcircusofphysics.com
This teapot differs from all others because you do not need to pick it up and tilt it in order to pour out a cup of tea.
https://www.youtube.com/watch?v=g5w9lRoms9M same video but with music
This type of teapot, now an expensive collector’s item, was patented in 1886 by John James Royle of Manchester, England. Tea leaves are put on a grill at the bottom of the teapot and then covered with hot water and allowed to steep. The lid (a cylinder) is then raised. When it is forced back down, a finger covers a small hole in the center, thus not allowing air to escape from the cylinder. As the cylinder with its trapped air descend, it pushes exactly one cup of tea out through the spout, which is bent over so that the tea pours neatly into the waiting cup.