Describes an activity using a large balloon to help children understand that, even though the horizon appears to be flat, the Earth is, indeed, round. Uses a toy ship to reinforce evidence from the first part of the activity. Stresses the importance of confronting naive theories at an early age. (CW)

Uses a demonstration done by John Tyndall in 1856 to show that geological processes can produce striking changes, such as slate formation, by slow and incremental means. Explains how Tyndall's demonstration can be replicated in the classroom using paraffin or beeswax to produce the layering change similar to slate. (CW)