 In 1773 he became High Sheriff of Bedfordshire and, upon discovering the state of the prisons, began a lifelong work of reform, spending a large part of his wealth and a great deal of time travelling over 50,000 miles investigating and reporting on the conditions of prisons across Britain and later Europe.The House of Commons heard his evidence on several occasions.In 1777 he published "State of the Prisons in England and Wales, and an Account of some Foreign Prisons".