Book excerpt: For the sake of comparability, it is advisable not to develop new class schemes but to use old ones. Yet presenting a new class scheme - HISCLASS - is exactly what this book does. Unlike existing historical schemes, HISCLASS is international, created for the purpose of making comparisons across different periods, countries and languages. Furthermore, it is linked to an international standard classification scheme for occupations - HISCO. The chapters in the book show how historical occupational titles classified in HISCO can form the building blocks of a social class scheme for past populations. The dimensions underlying classes are discussed. How, for instance, can manual work be distinguished from non-manual work? Skilled from non-skilled? And what did 'supervision' really mean?