How It’s Done: The Ever-Filling Jug
When magicians play around with water or other liquids, there’s probably a hidden compartment doing all the work. This kind of jug runs dry because its main compartment is empty, but the magician covers a hole in the jug with their finger while pouring. When they put the jug down, water flows into the main compartment, allowing for more to pour from an “empty” jug.