An imperical equation representing relaxation of stresses in annealing glass is derived. Although the derivation is based on Maxwells equation for viscous flow, consideration is also given to the changing viscosity as a glass anneals at a constant temperature. This new equation has been applied to data that were obtained by Adams and Williamson on the relaxation of stresses in annealing glass at various temperatures. It is shown that this equation applies very satisfactory to their data. It also appears to be much more suitable than the reciprocal relation proposed by these authors as a substitute for the wholly unsatisfactory exponential relation that is derived directly from Maxells equation. This exponential relation is unsatisfactory simply because it does not take into account the changing viscosity of annealing glass. The new equation leads to a clearer understanding of the nature and behaviour of glass because it does not neglect the change in viscosity.
