Review of B&W 7th edition, published in European Journal of Physics The publication of this new and expanded 7th edition of Born and Wolf's classic text on classical (i.e. non-quantum) optics is a significant event for the world-wide optics community, and it is worth summarising briefly its history.  It begins in 1933, when the Berlin publishing house of Springer brought out Max Born's German language textbook Optik.  During the 1939-45 war a need for Born's book was felt by many British and American scientists working for the Allied war effort, and in 1943 the U.S. Alien Property Custodian appropriated Springer's copyright and authorised the publication of a photo-lithoprint reproduction of the original.  After the war Born, who had held British citizenship since before the outbreak of war, was anxious to repossess his title, and was advised that the best way to do this was to publish an updated English translation.  To assist him in this task he hired, as an assistant with fluency in German and English  –-  and in Optics  --  Emil Wolf who, having graduated B.Sc. and Ph.D. in Bristol, was then researching with E.H. Linfoot at the Cambridge University Observatory.  So in 1951 Wolf started work with Born in Edinburgh. But Born's intention  --  the production, at an early date, of a translated and updated version of Optik  --  was not in fact realised.  What emerged instead was a great new treatise, Principles of Optics, a substantially larger and more ambitious work which took about six years longer to write than he had expected.  In fact, when Born retired from his Edinburgh chair in 1953 the book was far from complete, and it was not until 1959 that it was published. One of the factors which influenced the time it took to produce the book was Wolf's conviction that it should include an adequate account of the theory of optical coherence, which was evolving in the 1950s through the work of a small number of authors, of whom he was to prove the most influential. Optical coherence was presented in Principles of Optics as "a theory of optics in terms of observables"; as such it was ripe for quantization, and this process was at once stimulated by the appearance of the laser in 1960.  The development of the quantum theory of optical coherence by Glauber and others has had a profound influence on the development of optical science in the ensuing 40 years. Max Born had emphasised in his Preface to Optik that the proper foundation for the study of optics is electromagnetic theory, and devoted the first chapter of that work to electromagnetism.  In Principles of Optics the opening two chapters are devoted to a careful presentation of the electromagnetic theory, and its basic role is emphasised in the full title -- Principles of Optics: Electromagnetic theory of propagation, interference and diffraction of light.  This 'classical' field continues to be a fruitful area of research, and through to the present day 'B&W' has surely been the most quoted basic reference in the journal literature of optics.  It has been published in many languages throughout the world -- and in both authorised and unauthorised editions! The successive editions have incorporated many corrections and minor revisions, but this seventh edition has been extended by the insertion of significant new material.  The major addition is a complete new chapter -- between the chapters numbered 12 and 13 in the earlier editions - dealing with the scattering from inhomogeneous media of scalar and electromagnetic waves.  This is a welcome addition, and it includes a section on the use of Wolf's basic theorem of diffraction tomography in the interpretation of data from the scattering of millimetre wavelength acoustic waves in medical diagnostic procedures.  The interpretation of such data in the simpler case when X-radiation is scattered from macroscopic structures, so that a geometric-optical treatment is applicable, uses the Radon transform and is introduced in a new section in chapter 4 ("Geometrical theory of optical imaging"). Other additions include a tidy account of the Rayleigh-Kirchoff diffraction theory in chapter 8 ("Elements of the theory of diffraction"), and a very welcome account in chapter 10 ("Interference and diffraction with partially coherent light") of interference with broad-band light, the recently introduced spectral degree of coherence, and correlation-induced spectral changes (e.g. the Wolf shift in the spectrum of light propagating in free space from a partially coherent polychromatic source.).  There are also three new appendices, and a significant number of new references, the most recent of which are dated 1999. These developments, coupled with the new publisher's stylish and very handsome resetting of the text and photographic illustrations, give the new edition a pleasantly fresh feel.  Only perhaps in chapter 6 ("Image-forming instruments"), which has survived since the first edition with just one minor change, is there a slightly dated feel, but this chapter will still provide useful background for readers with no more than a scant familiarity with practical optics. Principles of Optics is, and will remain for many years, an indispensable and vital component in any optical library  --  and, thanks to the publisher's success in holding the price to such a reasonable level, the word 'library' can here be read as including the private bookshelves of workers in the field.  It is a splendid book. Richard M Sillitto, 20/8/00