Mr. Ruchlis, who has dealt with many physical sciences, has produced a book which might be considered a sequel to Clear Thinking (1962, P. 829, J-253). In this case, he deals with much similar material, but the emphasis is on scientific methods of approaching various problems. He first presents a clear discussion of these methods, defining terminology (such as hypothesis, theory, prediction, etc.) as he progresses. More than half the book is a series of photographs with precise scientific questions following. Through countless examples, and by working with the reader as a professor would with a student, Mr. Ruchlis illustrates convincingly the absolute necessity of an open mind. An exceptional book to follow up the author's other unique study. Mainly for the quicker, more alert among this age group.