A veteran writer of science books for younger children produces two titles that should prove useful and popular. Both provide interesting introductions to basic scientific principles by using easy experiments and projects to illustrate them. Science Fun With Peanuts. . . discusses plant propagation from seedling to minifarm; Science Fun with Toy Boats. . . (the stronger title) introduces basic physics as it moves smoothly from projects involving floating to those involving flying and, in doing so, demonstrates the relationships between the principles involved. The projects and experiments use materials found around the house (and classroom) and are illustrated with inviting, clear drawings and diagrams. Although the plant title does degenerate into a section on recipes and riddles, these books should find perennial use among young scientists and their teachers.