Concise, unified, and logical, this introduction to the study of the basic principles of fluid dynamics emphasizes the statement of problems in mathematical language. In addition to its value as a reference for professional engineers, this volume is suitable for advanced undergraduates and graduate students of mathematics and engineering. Some familiarity with the algebra of vector fields is assumed, and a useful appendix provides a succinct review of vector algebra. An introductory chapter covers fundamental notions from the continuum hypothesis to steady-state flow. Succeeding chapters explore conservation of mass, forces acting on a fluid in equilibrium, dynamic equations of motion, irrotational motion, integration of Euler's equation in special cases, and flows representable by harmonic functions. Additional topics include two dimensional flows, rectilinear vortices, general vortex motion, flows with a free boundary, and compressible fluids.