Earl Stanhope was the title of a line of English earls, several of whom were notable mathematicians and polymaths. The Third Earl, Charles Stanhope (1753–1816), invented the process of stereotyping and, in 1777, devised the first mechanical logical calculator. The Fourth Earl, Philip Henry Stanhope (1781–1855) was a mathematician who applied his knowledge to map-making and maze design. In 1818–30 he planted a maze according to a basic plan laid down by the Second Earl (1714–1786) that was probably the first to incorporate islands that defeat the familiar "hand-on-wall" method. (There are islands in the famous Hampton Court maze, yet the hand-on-wall method solves it.) His designs often had a number of islands, or just isolated lengths of hedge.