Translation Editor's NotePrefaceChapter I. Classification and Reduction to Canonical Form of Second Order Partial Differential Equations 1. The Equation for a Function of Two Independent Variables a11+uxx+2a12uxy+a22uyy+b1ux+b2uy+cu = f(x, y) 1. The Equation with Variable Coefficients 2. The Equation with Constant Coefficients 2. The Equation with Constant Coefficients for a Function of n Independent VariablesChapter II. Equations of Hyperbolic Type 1. Physical Problems Reducible to Equations of Hyperbolic Type; Statement of Boundary-Value Problems 1. Free Vibrations in a Non-Resistant Medium; Equations with Constant Coefficients 2. Forced Vibrations and Vibrations in a Resistant Medium; Equations with Constant Coefficients 3. Vibration Problems Leading to Equations with Continuous Variable Coefficients 4. Problems Leading to Equations with Discontinuous Coefficients And Similar Problems (Piecewise Homogeneous Media, etc.) 5. Similarity of Boundary-Value Problems 2. Method of Traveling Waves (D'Alembert's Method) 1. Problems for an Infinite String 2. Problems for a Semi-Infinite Region 3. Problems for an Infinite Line, Consisting of Two Homogeneous Semi-Infinite Lines 4. Problems for a Finite Segment 3. Method of Separation of Variables 1. Free Vibrations in a Non-Resistant Medium 2. Free Vibrations in a Resistant Medium 3. Forced Vibrations Under the Action of Distributed and Concentrated Forces in a Non-Resistant Medium and in a Resistant Medium 4. Vibrations with Inhomogeneous Media and Other Conditions Leading to Equations with Variable Coefficients; Calculations with Concentrated Forces and Masses 4. Method of Integral Representations 1. The Method of the Fourier Integral 2. Riemann's MethodChapter III. Equations of Parabolic Type 1. Physical Problems Leading to Equations of Parabolic Type; Statement Of Boundary-Value Problems 1. Homogeneous Media; Equations with Constant Coefficients 2. Inhomogeneous Media; Equations with Variable Coefficients and Matching Conditions 3. Similarity of Boundary-Value Problems 2. Method of Separation of Variables 1. Homogeneous Isotropic Media. Equations with Constant Coefficients 2. Inhomogeneous Media. Equations with Variable Coefficients and Matching Conditions 3. Method of Integral Representations and Source Functions 1. Homogeneous Isotropic Media. Application of the Fourier Integral Transform to Problems on the Infinite Line and the Semi-Infinite Line 2. Homogeneous Isotropic Media. Calculation of Green's Functions 3. Inhomogeneous Media; Equations with Piecewise Continuous Coefficients and Matching ConditionsChapter IV. Equations of Elliptic Type 1. Physical Problems Leading to Equations of Elliptic Type, and the Statement of Boundary-Value Problems 1. Boundary-Value Problems for Laplace's and Poisson's Equation in a Homogeneous Medium 2. Boundary-Value Problems for Laplace's Equation in Inhomogeneous Media 2. Simplest Problems for Laplace's and Poisson's Equations 1. Boundary-Value Problems for Laplace's Equation 2. Boundary-Value Problems for Poisson's Equation 3. The Source Function 1. The Source Function for Regions with Plane Boundaries 2. The Source Function for Regions with Spherical (Circular) and Plane Boundaries 3. The Source Function in Inhomogeneous Media 4. The Method of Separation of Variables 1. Boundary-Value Problems for a Circle, Ring and Sector 2. Boundary-Value Problems for Strips, Rectangles, Plane Layers and Parallelepipeds 3. Problems Requiring the Application of Cylindrical Functions 4. Problems Requiring the Application of Spherical and Cylindrical Functions 5.