Novelty Retro Glass Beautiful Design Happy Drinking Dipping Dippy Bird Duck

The Original Drinking birds are toy heat engines that mimic the motions of a bird drinking from a fountain or other water source. It is sometimes considered a perpetual motion device. These were around when I was a kid 50 years ago. Cool then and cool now.

When the head of the bird is moistened with water, it will repeatedly bend down and appear to be drinking from a cup of water in front of it. The dunking is due to the water evaporating, which cools the head and reduces the pressure of the gas inside. The liquid inside the bird rises from his tail towards his head, causing him to bend down and appear to be drinking. When the bird dunks, the liquid returns to its tail, and the process begins again. In essence, this is a small, cleverly designed thermodynamic engine which only needs water to run!