A series of flow and recovery tests are used as a basis for describing and interpreting the elastic, viscous, and tensile properties of a typical solid linear high polymer. Extensions of viscose rayon at 70°F and 65 percent R.H. are given under loads of 0.1 to 1.0 grams per denier (1900 to 19,000 lb. per sq. inch) for times up to 106seconds. Recoveries at 70°F are given for times up to 106seconds at 65 percent R.H. and also after wetting and reconditioning to remove internal strains. The data are interpreted in terms of changes in modulus, viscosity, restoring forces, viscous flow, crystallization, and internal load distribution.