The practice of confining convicted criminals in prison for a stipulated period of time ? to punish or reform ? is a modern western innovation. Pentonville in north London, opened in 1842 and said to be the first modern prison, had four wings radiating from a central hub from which guards could observe every cell, each holding a single prisoner. The ‘modern? prison then became one of many western innovations (including the railway, scientific medicine and the filing cabinet) transported to the colonial world from the mid-19th century.