The increasing size of urban populations led to overcrowding in the cities as the masses crammed into all available living space. A new word, ‘slum’, passed from slang into orthodox use. Originally signifying ‘sleepy’ areas of ‘slumber’ off the beaten track, it came to describe areas of squalid and deteriorating housing associated with poverty and disease. Many of the problems faced by poor city dwellers started in such homes. Although bad housing was by no means a new phenomenon in the nineteenth century, what differentiated the problem after 1800 from earlier cases was its scale.
Existing housing – often the former residences of wealthier classes that had moved on – was endlessly subdivided and sub-let. A single room, even one in a cellar, might be rented by several families. New housing was quickly erected, usually the work of speculative builders who, working in the period before modern building regulations, often used cheap materials and gave little thought to design. No attention was paid to reducing density of occupation, which maximised financial returns. Back-to-back construction was widespread, with exterior walls sometimes no more than half a brick thick. Dingy narrow streets led to even darker alleys and courtyards that were soon foetid from the lack of airflow and accumulation of domestic waste. Poorly furnished and providing little shelter from the elements, many houses also doubled as workplaces; others had animals living alongside the human tenants.
The mean and distressed domestic lives of the citizens of the industrial towns began to trouble the imaginations of social commentators. For the French traveller Alexis de Tocqueville, Manchester was a 'new Hades'. In 1835 he recorded that:
In the early nineteenth century most dwellings had relied on cesspools for the disposal of collected sewage. Ideally these were emptied and cleaned regularly, and the contents used to fertilise local farmland. As the urban populations multiplied, such systems became ineffective. The cesspools filled and then overflowed, saturating surrounding land and contaminating the local environment. In 1842 a surveyor described the problem when visiting two London houses:
For many communities, local rivers had been used for both water supplies and drainage. As areas became more intensely urbanised these rivers were increasingly used for sewage disposal. But they did little more than transport the problem elsewhere. By the middle of the century inadequate disposal systems were collapsing under the strain. In addition, nearly all sources of drinking water were liable to be contaminated, either by overflowing cesspools and crumbling drains or by sewers discharging upstream of water intakes.
Such problems could occasionally be dramatically dangerous. In 1846 the river Walbrook in London, which was covered over by buildings and unventilated, harboured such a quantity of noxious gases that it exploded – producing a tidal wave of sewage that swept away three houses in nearby Clerkenwell.