
1) Mechanical puzzle
Found on
https://www.crosswordclues.com/clue/puzzle-jug

A puzzle jug is a puzzle in the form of a jug, popular in the 18th and 19th centuries. An inscription typically challenges the drinker to consume the contents without spilling them, which, because the neck of the jug is perforated, is impossible to do conventionally. Known inscriptions include: ==Examples== The earliest example in England is the E...
Found on
http://en.wikipedia.org/wiki/Puzzle_jug

A puzzle jug is a puzzle in the form of a jug. The challenge of the puzzle to drink the contents without spillage is often written on the jug. This is certainly impossible to do in the conventional way because the neck of the jug is perforated.
Found on
http://www.antique-marks.com/antique-terms-p.html

A practical joke in the form of a drinking vessel that, unless the trick is known, spills all over the user when he tries to take a sip. As the jug is tilted, liquid pours out from the pierced decoration surrounding the pot. The puzzle is to learn the secret of how to successfully drink without gett...
Found on
http://www.daviddarling.info/encyclopedia/P/puzzle_jug.html

Jug with several spouts and holes pierced in its neck, designed to make both pouring and drinking without spillage virtually impossible. The liquid is drunk by sucking a nozzle connected to a hidden tube. Puzzle jugs were popular throughout Europe from the 17th to 19th centuries, and made in earthenware and STONEWARE.
Found on
http://www.encyclo.co.uk/visitor-contributions.php

a drinking jug of the 17th and 18th centuries, so made as to challenge the drinker to drink without spilling or spraying the contents.
Found on
https://www.infoplease.com/dictionary/puzzle-jug
No exact match found.