Stephen Halliday has followed up his study of Sir Joseph Bazalgette, The Great Stink of London, with a wider study of how Victorian engineers and other innovators made English cities healthier. The Great Filth is a well-written and accessible book that looks at medical, social, scientific, political and infrastructural developments. Gems of detail shine out amid the sludge and sewage. The central pages include eleven portraits of some of the main players – with a fabulous photograph of a campaigning statistician called William Farr.

The death rate declined as the Victorian period progressed. Halliday is keen to place much of the credit for this at the boots of the engineers who cleaned up and improved the water supply. The heroes in the quest to remove filth and reduce disease included the water engineers James