Place the larger glass bulb in your hand, wrap your fingers around it and watch what happens… You’ll see the colorful liquid begin to shoot up the twisting, turning tube. Once at the top, the colored liquid will begin to bubble‚ just as if it were boiling!
This is a classic science toy that is sure to be a favorite on your desk or shelf. Recommended for ages 12 and up.
How does it work?
The heat of your body causes the air in the hand boiler to expand. As the air expands, it forces the liquid to move up through the tube. When the liquid has moved to the top bubble, the air is still expanding and it bubbles through the liquid, making it look like it is boiling.