Cornelius represented Canada at the 1908 Olympic Games in London where he won the bronze medal with a throw of 48.50m. He was a Canadian Champion in 1907 in both the 56lb weight and the hammer throw and set a Canadian record in 1910 for the hammer and weight for height events.

Cornelius set a world record of 4.93m in the 56lb weight for height event in 1910.