Abstract In order to study the elastic properties of cotton, it is recognised that there is a need for preliminary investigations into the effect of varying the time of application of stresses to the material. The present research deals with the changes in dimensions of single cotton hairs under longitudinal stresses in their relation to the time of application of the loads. It is found that elongation and recovery from strain are irregular processes which may continue for long periods of time, though frequent repetition of the loading conditions tends to the establishment of an elastic state. Besides throwing some light on the nature of certain elastic constants of cotton, the work has a direct bearing on the changes in dimensions which cotton goods may suffer with time. Extension of the methods to yarns and fabrics would indicate the causes which produce contractions in length and width which are sometimes encountered in piece goods on storage.