In 1963 and in 1966 -- 1967 he was at the University of Cambridge .
After a visit to the new mathematics department developed by Erik Christopher Zeeman at the University of Warwick Eells became a professor of mathematical analysis there in 1969 .
In 1963 and in 1966 -- 1967 he was at the University of Cambridge , and after a visit to the new mathematics department developed by Erik Christopher Zeeman at the University of Warwick Eells became a professor of mathematical analysis there in 1969 .