W. H. Smith, Canada: Past, Present and Future (1851), vol. 1

A gazetteer of Canada West with county business directories, read in the archive.org full text. In the directory for the united counties of Northumberland and Durham: “Short, John, postmaster Newcastle” and “Jeffrey, A., merchant, (hardware) Cobourg.” John Short was the father of John Gerald Short; Andrew Jeffrey, mayor of Cobourg in 1852, was very probably his wife Mary’s brother (research/ellingwood/Ellingwood_Wives_Families.md).