Questions and Exercises.
1. If you place a saucer full of water outside on a hot day in the morning, and go back to it in the evening, you will find the saucer dry. Where has the water gone? 2. Fill a tin can with a mixture of salt and snow (or chopped ice). Place it in a warm room. Frost comes on the outside of the tin. Place a glass jug of water in the same room. Dew is formed on the outside of the jug. Can you explain this? 3. Let the steam puff of the kettle strike against a cold sheet of glass or metal, or a slab of stone. What is formed?