This is truly a how-to book on a grand scale for the serious amateur experimentalist, teen-age or older, who wants a real taste of modern scientific investigation. More than 50 projects are presented, taken from the author's excellent feature published every month in the Scientific American. They have been expanded and revised and are beautifully illustrated in detail by Roger Hayward (256 drawings and photographs). They offer the scientifically minded hobbyst an opportunity to build economically from scratch such important working instruments as a cloud chamber, research rocket, seismograph, microscope, X-ray machine, atom smasher, and many others (simpler ones too), and to partake in experimental investigations of phenomena and techniques in all the major fields of science from archaeology to nuclear physics. There is no question that many of these projects will appeal to the gifted science minded youth and provide a practical source of inspiration to his talents. Ought to be in all school, college and public libraries for those special students who want to do and see for themselves in science.