Historical and technical insights about puzzle Jugs
The container-puzzles are an ancient form of game. Greeks and Phoenicians created containers that were filled through a hole in the bottom.
Already in IX century, some containers of this kind were described in the Turkish Book. We know that in the XVIII century the Chinese produced this kind of drinking containers.
Another example is the Puzzle Jug: the neck of the container is completely drilled, therefore allows the liquid to be poured into the container, but not from it. Hidden from the player's eye, there is a small tubular duct that passes through the handle and along the upper edge of the container to the nozzle.
Other examples of these puzzles are the Communicating Cups.