Puzzle jug

This top part of a jug was discovered in the territory of Vilnius Lower Castle. It has a narrow neck with two rows of 0,5cm diameter holes. Due to this unusual construction it was not possible to drink out of this jug without spilling the drink over yourself. Such puzzle-jugs were used for drinking games and were popular in Western Europe in the 16th-19th centuries.
The trick of these jugs is based on rules of physics. The secret hides in the edge of the neck as well as ducts inside the handle. This fragment found by archaeologists has a round edge with a small hole that reaches a duct inside. This duct on the inside of the edge reached a hollow handle, which was used as a kind of straw to drink liquid from the bottom of the jug without tilting it. But this would not be possible without pressing up on a hole hidden in the handle. That would create a vacuum and the liquid would reach the edge through the handle.
Only a really smart potter could make such jugs. Descriptions on how to make such vessels can be found in a manuscript by Cipriano Piccolpasso from mid-16th century, called ‘Three books about art of the potter‘ (Li tre libri dell'arte del vasaio). Perforated dishes had to be constructed in such a way that they would not be understood by and unskilled user. Many puzzle-jugs were destroyed out of disappointment and frustration, when a way to drink from it would not be found.
In Lithuania such vessels were made up until 1930s.