[2] He served during World War II as a captain in The Governor General's Horse Guards.
Cornish was elected to Toronto City Council as alderman for Ward 2 in 1950 and was re-elected in 1951 and 1952.
[2] Cornish returned to his law practice following his defeat and wrote and published the Quinlan Reports summaries of Ontario Municipal Board proceedings.
[1] Cornish was appointed a judge in the County of York in 1971 and retired from the bench in 1981.
[2] A devout Roman Catholic, Cornish was involved in a number of lay organizations including the Michaelmas Conference at St. Michael's College and the St. Vincent de Paul's Society.