"Sources of High-Intensity Ultrasound" has been prepared by a staff of Soviet scientists under the editorial supervision of Pro­ fessor Lazar Davidovich Rozenberg. Professor Rozenberg is Di­ recror of the UHrasonies Laboratory of the Acoustics Institute of the Academy of Seiences of the USSR and is widely recognized as one of the outstanding acousticians in the USSR. This English translation brings to Western readers the first book' of a planned three-part monograph entitled "Physics and En­ gineering of High-Intensity Ultrasound," which covers Sources of High-Intensity Ultrasound; High-Intensity Ultrasonic Fields; and Physical Foundations of Ultrasonic Technology. The series is based largely on original research carried ou~ by the authors and their colleagues over the last decade, primarily at the Institute of Acoustics in Moscow, supplemented by work at the Central Sci­ entific Research Institute of Ferrous Metallurgy and the Scientific Research Institute of Technology. The English edition of "Sources of High-Intensity Ultrasound" has been divided into two volumes. Volume 1 treats extensively the theory and performance of gas-jet sound generators, magneto­ strictive ferrites, and uHrasonie focusing transducers. Included in some detail is L. D. Rozenberg's valuable contribution to ultra­ high-intensity focusing systems. Volume 2 addresses the coupling of ultrasound to process media, the characteristics of flexural-mode waveguides and tor­ sional vibrational systems, and concludes with a chapter on sen­ sors for the measurement of high-intensity acoustic waves and their calibration.