What is an equinox? What are the solstices? How are the tropics defined? Find out with The Eloquent Earth, an overhead demonstrator designed by geography teacher David S. Worrall. By placing the model on the overhead projector, you can easily show the Earth's tilt relative to the sun's rays for any time of the year. This model can also be used to teach about the changing seasons, variations in the length of days and nights, and different times of sunrises and sunsets. Includes: complete teacher's guide.Grades 8-11.