This 1961 book presents a concise and systematic treatment of two-dimensional subsonic, inviscid fluid motion and its aeronautical applications. Part I surveys the relevant fluid dynamics, assuming only a basic knowledge of the topic. In Part II, the methods of conformal mapping and Cauchy integrals are developed, on the assumption that the reader has only an elementary understanding of complex variable theory; this will be of interest to a wide range of applied mathematicians and engineers. In Part III, the methods are applied to several problems in fluid mechanics and aero dynamics. The text provides an extensive account of mixed boundary-value problems and treats such examples of these problems as occur in ventilated wind-tunnel theory, jet-flap theory and unsteady Hemholtz motions.