I. Rational mechanics of materials.- II. Polar and oriented media.- III. Thermodynamics of visco-elasticity.- IV. Electrified materials.- V. The ergodic problem in classical statistical mechanics.- VI. Method and taste in natural philosophy.- Appendix: Text of the Chairman???s Introduction to the Colloquium on the Foundations of Mechanics and Thermodynamics held at the U. S. National Bureau of Standards, Washington, October 21???23, 1959.Springer Book Archives