Text of the Annual Mather Lecture to the Textile Institute (Manchester) by Dr. W. Lawrence Balls, reviewing how scientific methods have changed the cotton industry and forecasting its future. He discusses the variability of cotton hairs, blending versus sorting, competition from artificial silk, a shift of cotton toward engineering uses such as tire cords, Johannsen's pure lines in seed supply, and analysing cotton in terms of single hairs. He also anticipates super-drafting that would bypass flyframes and a continuous ring-spinning machine (his "Rule" frame) resembling the mule.