Hand Boiler Are you hot or not? Find out with this cool science experiment. email to friend
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Find out if you're "hot" when you experiment with the relationship between temperature and pressure. Just wrap your hand around the bottom bulb and the liquid will go up to the top - not because the kids squeezed the boiler, but because the heat from their hands warms the gas, which pushes the liquid into the top chamber. After a little while, challenge your students to get the liquid back to the bottom of the boiler without turning it over. Works on the same principle as the old Love Meter, common in drugstores and five-and-dimes all over America.

Each Hand Boiler measures approximately 6 inches tall... and we'll send you one! Please note, design and color may vary.

How does it work?

When the liquid in the bottom bulb is heated with your hand, an increase in temperature creates an increase in pressure which causes the liquid to move up the tube to the top bulb. When enough liquid transfers from the bottom bulb, alcohol vapor is forced up the tube, causing the liquid in the top bulb to appear to "boil."

What does it teach?

In a closed container, as the temperature goes up, so does the pressure. As the temperature increases, the molecules of gas in the container move faster, which increases the pressure. As the pressure increases in one of the chambers, the liquid will be pushed into the other one. Notice how hand temperature varies in different people, and compare your data with others in your group. Then decide who's hot and who's not!