Water Wheel Timer;

This cute and colorful timer has two wheels that spin as droplets of neon colored water spill through a funnel and catch on the wheel in the lower chamber. Simultaneously, lighter drops of oil rise through the colorful water and spin a wheel in the upper chamber. Since the water is denser than the oil, it is forced through a funnel and down onto the paddles of the little wheel. A fun lesson in the density of liquids, this timer goes for about two minutes until you turn it over to start it again. Kids are fascinated by the properties of oil mixed with water and this makes an amusing surprise that they can put on their desk and watch as the oil and water repel each other and spin the small wheels.