Engage students in small groups with dramatic simulations of the earth's dynamic natural processes. Accompanying activities encourage students to ask: "What if?" and watch as a teacher tests their hypotheses. At half the size and about half the cost of the original unit, the junior model is also illuminated and includes nearly all of the same demonstrations (except sea-floor spreading and upwelling). Dimensions: 22" L x 6" H x 3.75"W. 55-page manual.