Between 1830 and 1914 Britain underwent a major social revolution. It became, what it is today, an urban society. The early stages of that transformation were inevitably accompanied by social dislocation and hardship, as the market mechanism, attuned to economic rather than social stimuli, sought to cope with the rapid growth of urban numbers. Charles Booth was largely concerned with examining the amount of social suffering amongst those households with families of school age and, on the basis of these data, making assumptions about the size of the poverty problem in London as a whole. Primary poverty, which accounted for 9.91 per cent of York's population, denoted an aggregate family income which was insufficient to maintain the members of the household in a condition of physical efficiency. But even if the amount of primary poverty was reduced over time, it still remained, before and after Seebohm Rowntree, a fundamental social problem which neither Poor Law nor philanthropy could eradicate.