Between 1830 and the end of the 1840s the medical world came up with new ways of thinking and researching about puberty. These were statistical in essence, endowed with the sanitary spirit of metropolitan and colonial reform and with the positivist belief in the neutrality and accuracy of numbers in revealing the truth of biological and social phenomena. Towards the mid-19th century, counting and measuring for statistical purposes had become a common affair in the modern administration of the nation-state. The practice gave rise to a constellation of new categories by which people were first identified, then quantified, and finally compared in terms of deviation from average values. Until the dawn of the 19th century, child labour in agricultural and manufacturing work had ostensibly been considered unproblematic. Orphaned, abandoned, or ‘incorrigible’ poor children were often recruited in compulsory fashion and without any remuneration from early ages until reaching maturity.