This simple experiment will show you in a dramatic way that water has a high capacity to hold heat. You will need a paper cup (one that isn't waxed) and a campfire or barbecue. Fill the cup three-quarters full, and place it where it can be heated from below. Then start the barbecue, or light the fire. What you will notice is that the top of the paper cup will burn down to the level of the water, and then stop. The cup will not burn where there is water on the other side of the paper. Why does this happen? Water has a high capacity to hold heat, and its temperature will not go above 100° C as long as it is a liquid. Paper won't burn until its temperature reaches about 233° C. The heat of the fire is easily absorbed through the paper and into the water, and the paper doesn't ignite. The water will boil away, and as it does, the top of the cup will slowly burn, but never below the level of the water. Try making an egg omelette in a paper bag over a campfire! Main Page