This article introduces a new set of estimates of average weekly age-and sex-specific earnings paid at each year of age between 13 and 60 years of age to males and females employed in the British cotton industry between 1833 and 1906. As one example of the use of the estimates, the article shows how the estimates provide insights into changes in the male-female earnings gap in one key industrial group of workers in Victorian Britain. An appendix provides estimates of the population-weighted average weekly full-time money earnings of British cotton operatives, in pence per week, by sex, of the age groups: <13, 13-17, 18-60+, and 13-60+. C urrently available estimates of labour earnings before 1914 rarely distinguish male from female earnings, or movements in age-specific earnings in any detail. Estimates of earnings that do not make these distinctions are of limited value to historians and economists interested in issues such as the male-female earnings gap, the formation of human capital, and family economics, where sex and age are crucial aspects of the analysis. Evidence capable of dealing with these issues is required, preferably covering extended periods of the working lives of different groups of workers. Recent research has yielded some evidence in this direction; nevertheless, the extreme scarcity of age-and sex-specific earnings data remains a key limitation on historical inquiry. 2 This article presents a new set of estimated average weekly age-specific earnings paid to males and females employed in the British cotton industry between 13 and 60+ years of age for every year between 1833 and 1906. 3 The estimates can be used to make general statements about average age-and sex-specific earnings in the cotton industry, provided that their strengths and limitations are understood. As 1 We would like to thank Jim Oeppen, Tim Hatton, Rebecca Kippen, Colin Forster, R.V. Jackson, and three anonymous referees for their comments on earlier drafts of this article.2 Boot, 'Lancashire cotton workers'; Johnson, 'Age, gender and the wage'; Horrell and Humphries, 'Women's labour'; Burnette, 'Female-male wage gap'. 3 We have not estimated age-specific earnings of children under 13 years of age. We do, however, include a set of estimates of the average earnings of children ('part timers') in app. I. The earnings of these workers were strongly influenced by increasing legal restrictions on their employment imposed by the factory acts and compulsory schooling, as well as the extension of half-time work, making it difficult to estimate their earnings in a manner consistent with our estimation of the earnings of full-time workers. Evidence derived from the census of earnings conducted for the Royal Commission on the Employment of Children in Factories (1834) and from Wood, 'Statistics of wages', leads us to conclude that the weekly earnings of children under 13 years of age remained relatively unchanged between 1833 and 1906, though because children worked full time in 1833 and only half time in 1906, the figures imply a d...