This book addresses itself to two major problems: the increasing demand for water and the increasing limitations on energy use. Within the general framework of problems regarding pumps and pumping installations, attention is focussed on variable-speed pumps. The book considers all aspects of pumps and pumping systems theory. The first four chapters cover the theory of pump operation and control, and with the phenomenon of cavitation. The next three chapters treat the computations and operation of a pumping system in both continuous and discontinuous flow conditions, as well as the computation methods and control of water hammer by means of automatic hydraulic valves. Chapters 8 to 13 deal with the theory and structure of automatically controlled pumps, and with the speed regulation systems of the electric motors driving the pumps. The last chapter analyses optimal schemes for fixed- and variable-speed pump installations for various typical applications and gives associated operation diagrams. Throughout the book, numerous tables and diagrams support the written text.