The motions of liquids in moving containers constitute a broad class of problems of great practical importance in many technical fields. The influence of the dynamics of the liquid on the motions of the container itself is a most interesting and complex aspect of the general subject, whether one considers only the rigid-body motions of the container or its elastic motions as well. It is most fitting therefore that this translation of Professor Rapoport's book has been undertaken so promptly following its original publication, so as to make readily available this rather detailed account of the mathematical foundations underlying the treatment of such prob lems. Since most of this vast body of analysis has been developed over the past decade by scientists in the USSR, and has therefore been largerly unavailable to those unable to read Russian, this volume will undoubtedly be of great value to many of us. H."