How the Peruvian Whistling Vessel Works

A whistling vessel (huaco silbador) is an ancient type of ceramic art in which water moves between two chambers and produces a bird whistle. Even the reproductions are hand made and quite expensive. Steve Mould wanted to look inside to see how they worked, but considering the cost, ended up using x-ray technology to see inside. To really grasp the way they work, he ended up destroying at least one anyway, but the mechanism, and how it varies from piece to piece, is quite fascinating. The last minute of this video is an ad.