 He worked for periods at the Bank of Western Australia and the Agricultural Bank of Western Australia, and later at private firms in Perth and Kellerberrin (a small Wheatbelt town).Cornell served on the Kellerberrin Road Board from 1942 to 1947, including as chairman from 1945 to 1947.He entered parliament at the 1947 state election, defeating the sitting Labor member, William Telfer, in the seat of Avon.