Interesting and of wide general appeal. The author follows through from briefly stated theoretical aspects of science to the practical application to make life more comfortable, economical and efficient. Refrigeration, air conditioning, heat, light, vaccuum cleaning, electric and gas cooking, valuations of good content and balanced diet, endocrinology, blood analysis, developments in criminology, and so on. I found it fascinating reading and stimulating to the imagination. Should have a plus sale for boys and girls interested in applied science.