In 1775, he journeyed to prisons all over Wales and England. He was shocked at the conditions people had to live with. He wrote a book on the state of prisons. He visited Caernarvon, Swansea and Wrexham. Caernarvon was derelict, lacking drainage and freshwater. Some things he suggested was that there should be more space, sanitary buildings, training programmes and regular vicar visits.