This book contains a mathematical exposition of analogies between classical (Hamiltonian) mechanics, geometrical optics, and hydrodynamics. In addition, it details some interesting applications of the general theory of vortices, such as applications in numerical methods, stability theory, and the theory of exact integration of equations of dynamics.

1. Hydrodynamics, Geometric Optics, and Classical Mechanics.- 2. General Vortex Theory.- 3. Geodesics on Lie Groups with a Left-Invariant Metric.- 4. Vortex Method for Integrating Hamilton Equations.- Supplement 1: Vorticity Invariants and Secondary Hydrodynamics.- Supplement 2: Quantum Mechanics and Hydrodynamics.- Supplement 3: Vortex Theory of Adiabatic Equilibrium Processes.- References.