This book, originally published in Moscow in 1965, is of interest to a wide scientific and technical audience, including geophysicists, meteorologists, aerodynamicists, chemical, mechanical, and civil engineers--in short, all interested in the fundamental problems of flow, mass, and heat transfer. The authors deal with the theory of hydrodynamic instability and the development of turbulence, the application of dimensional analysis, and the theory of similarity to turbulent flow in pipes, ducts, and boundary layers, as well as free turbulence. They discuss semiempirical theories of turbulence, develop the similarity theory for turbulence in nonhomogeneous media, and present Lagrangian characteristics of turbulence and the theory of turbulent diffusion. Every effort has been made to present a wealth of experimental material; a large number of examples are drawn from physics of the atmosphere, permitting a generalization of results beyond that which can be obtained in the laboratory. Considerable attention has been given to Kolmogorov's theory of the local structure of developed turbulence and to the theory of turbulence in stratified media.