The Drinking Bird has been around for years, but you can't fool us... you've always wanted one!

Here's your chance! But do you understand how the Drinking Bird works? Do you grasp the complex relationship between chemistry and physics that makes this simple heat engine tick?

Here is the secret:

1. Water evaporates from the felt on the bird's head.

2. Evaporation lowers the temperature of the glass head (heat of vaporization).

3. The drop in temperature causes the dichloromethane vapor inside the head to condense.

4. The lower temperature and the condensation combined cause the pressure inside the head to drop (due to the Ideal Gas Law).

5. The higher vapor pressure in the warmer base pushes the liquid up into the neck.

6. As the liquid rises, the bird becomes top-heavy and tips over.

7. When the bird tips, the lower end of the neck tube rises above the surface of the liquid.

8. A bubble of warm vapor rises through this gap in the tube, displacing liquid as it moves.

9. The liquid flows back down into the lower bulb, and the pressure between the upper and lower bulbs equalizes.

10. The weight of the liquid in the lower bulb causes the bird to return to its upright position.

11. The liquid in the lower bulb is warmed by the ambient air, which is at a slightly higher temperature than the bird's head.

Pure science, packaged in a cool gadget!

email:miller@supercoolgift.com