Starting from first principles, this book looks at the aerodynamic behavior of axial and radial compressors. The text starts with general ideas, and then moves through the simple aspects of axial compressors to the more advanced three-dimensional ideas. Radial compressors are treated in two sections: impellers and diffusers. Noise and aeroelasticity are considered in one chapter, and another chapter looks at measurement and computational techniques. The book is unique in the approach and treatment. The emphasis is on physically based understanding, and these ideas and this approach do not age. Considerable effort is taken to explain the cause of observed behavior, rather than to provide methods or recipes to be followed. For the 2004 reprint edition there is a new introduction summarizing major developments since the first publication. This is complemented by a supplementary bibliography of important new papers.