Gr 4-8 Attractive covers are only the beginning of these two interesting titles. Berliner begins his book with an excellent definition of what a research plane is, and follows it with a brief history of aviation research. The remaining three chapters are devoted to various types of aircraft. The subtopics within the chapters are often quite short, but do give a good thumb-nail sketch of a particular plane. The text is readable, and does not include a great deal of technical jargon. Briggs has done an equally fine job of introducing the subject of balloon flight. A short history of ballooning quickly leads into a brief discussion of several different types of balloons and the research each is designed to carry out. Both titles are liberally illustrated with black-and-white and color photographs. The photos and captions correspond well with the text. Introduce these two titles and watch their circulation soar. Eldon Younce, Harper Elementary School, Kans.