THE KINGFISHER YOUNG DISCOVERERS ENCYCLOPEDIA is an extraordinarily extensive compendium of science fact and activities. Devoid of science-ese, this volume is bound to spark and engage young minds.

Kids eager to explore their environment will discover activities for making a sound cannon and a sound amplifier, as well as a crude but effective burgler alarm. Other experiments reveal how to test the greenhouse effect, as well as how to create a terrarium and a backyard nature reserve.

The book's emphasis on care and respect for the natural world and its inhabitants is especially evident in the last chapter, "Nature in Danger." In sections such as "Keeping the Balance" and "Save Our Seas," young readers learn that pollution and indiscriminate treatment of the natural world threatens all living things: "Plants and animals that share the same habitat rely on each other for their survival."

This chapter reinforces the need for preservation of the environment by noting, for example, that the rosy periwinkle, a flower found in the rain forest, is used to treat leukemia. There is also a close-up photograph of two beautiful but decapitated leopard heads, their bodies poached for the fur trade.

The illustrations, both full-color drawings and photographs, are instructive, and an excellent complement to the science lessons. One nine-year-old girl tackled the experiment that illustrates the impossibility of making a flat map of the globe; she finally gave up on the challenge but not before sacrificing the peels of five oranges!

Kathy Wollard's How Come? Planet Earth is a Q&A book that explores natural mysteries such as why cats purr and how clouds form.