The Symposium on the Photoelastic Effect and its Applications sponsored by IUTAM with the cooperation of the Permanent Committee for Stress Analy sis and the Society for Experimental Stress Analysis was convened at IBM Ed ucational Center, Ottignies, Belgium, September 9-14, 1973. The subject of the Symposium was the study of the interaction of matter with light in a broad sense. More specifically three main subjects were proposed: (1) Classical and advanced photoelasticity (2) Rheooptics and (3) Theoretical mechanics of a continuum in interaction with the electro-mag netic field. For a better understanding of the problems at hand, three general conferences presented these three subjects and three others treated (4) the available ex perimental methods for measuring the optical properties, (5) streaming dou ble refraction and (6) magneto-and electro-photoelasticity, making a total of six general conferences. The scientific program included also 21 papers. Plen ty of time was provided for discussions after the conferences and after the pa pers. The symposium ended with two concluding conferences followed by a gen eral discussion. In an introductory conference, Professor R. Van Geen (Brussels) has put the study of the Photoelastic Effect in its right place, and given further com ments on the aims of this Syposium.

Inhalt
The Meaning of the Photoelastic Effect.- General Reports.- Classical and Advanced Methods of Photoelasticity.- A Critical Review on the Use of Polymers in Photoplasticity.- The Interaction of a Material Continuum with an Electromagnetic Field in the Frame of the Classical Theory of Field.- Phenomenological Analysis of Mechanical and Optical Behaviour of Rheo-Optically Simple Materials.- The Available Experimental Methods for Measuring Optical Properties of Matter.- The Use of Atomic Gauges for Studying Local Stress Effects in Crystals.- Streaming Double Refraction, a General Report.- Additional Physical Fields in Photoelasticity.- The Photoelastic Effect from a Theoretical Point of View.- Electrodynamics of Photoelastic Media: Theory and Experiment.- Higher Order Photoelastic Interactions: Theory and Experiment.- Rotation-Dependence of the Photoelastic Effect.- Some Magneto-Optical Effects Related to the Faraday and Hall Effects.- Electro-Optical and Magneto-Optical Effects.- A Note on Rational Continuum Mechanics and the Description of Magnetizable Dielectric Fluid Mixtures.- Applications of the Photoelastic Effect.- Photoviscoelasticity: Theory and Practice.- Polarimetrie et Photoelasticimetrie.- Photoelastic Effect Analysed by Means of the j-Circle Method.- Static and Dynamic Ponctual Method for the Determination of the Neutral Axis and the Algebric Value or the Birefringence for a Plane Plate.- Recent Work in Absolute Measurement of Birefringence.- A Compensation Method in Scattered Light Photoelasticity.- On the Determination of Scale Functions for the Transmission of Results in Photoelastic Analysis of Plate Problems.- Some Remarks to the Photoelastic Investigations of Dynamic Problems.- Photoelastic Study of Elastohydrodynamic Lubrification.- Stress Concentrations in Monolithic Structures Subjected to Mechanical and Thermal Loading.- Conclusions.- Concluding Summary.