Dippy bird: Large glass bird containing ether oscillates.

Dippy bird: Large glass bird containing ether oscillates. The glass 'Dippy bird' contains ether. The head is covered with water-absorbent material. First, the head of the bird is completely soaked with water. Then the bird is positioned over a beaker of water a little lower than leg height. At first, the bird is upright, with the ether in the bottom bulb. Water evaporates from the dippy bird's head, cooling the ether vapor in the upper bulb which decreases the volume and sucks up the liquid ether from the bottom bulb. The bird then tips, causing ether vapor to bubble to the top, and ether liquid drains back to the bottom. Meanwhile the head of the dippy bird is resoaked with water and the cycle continues. TEMPERATURE AND EXPANSION.
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Unfortunately it takes a fair amount of time for the bird to ``dip.'' Don't bother just wetting the beak, just soak the entire head so that the bird oscillates more swiftly. You can see the ether creep upwards by watching it carefully and you can have a conversation while drawing the participants attention to that. This could serve to keep participants engaged while they wait for the dip. As always when you present a demo make sure you ask the participants questions before you demonstrate and after. Think about the concepts involved beforehand; having a friend ask you questions about it can be very revealing as to if you understand it well or not. Whenever you ask a question count to five (or at least three) in your head waiting for an answer before you stay anything else.