This book offers an accurate, explicit, and objective summary of the physics of modern radiology. The opening historical chapter, which is at once factual and fascinating, is followed by several chapters on the fundamental theoretical concepts of matter, electricity, magnetism, and radiation. The remaining 15 chapters deal with practical considerations of production, measurement, and control of the ionizing radiations and with problems of protection. The book as a whole is a model of compactness, the addition of 150 pages since the first edition being necessitated by new chapters on radioactive isotopes, high energy accelerators, and super-voltage generators, with new tables and about 70 added illustrations. It is commendably free from errors, obscurities, and affectations and is well provided with bibliographies and an index. It will be extremely useful both as an introduction to the subject for students and as a reference work for specialists in the field.