**I think this is the best of these picture science books. Not perhaps the most original (Let's Find Out still holds that palm), but the one with the widest appeal for the inquiring small boy or girl. It should prove a godsend to the parents who don't know how to explain what makes water run when a tap is turned; how the furnace distributes heat through the house; what makes bulbs light and bells ring. Safe experiments with equipment every home provides -- and a picture quiz at the end -- make this a perfect how-to-do-it-at-home book. And a sure favorite with the imaginative teacher.