books.google.ca - Since 1956 when Ontario's historical plaquing program was begun, more than 1,000 markers have been erected throughout the province.The range of subjects commemorated is astonishing -- from mining rushes in northern Ontario to the invention of the socket-head screw ... from Harold Innis to Stephen Leacock...http://books.google.ca/books/about/Discover_Your_Heritage_A_Guide_to_Provin.html?id=pkp1MNny-c8C&utm_source=gb-gplus-shareDiscover Your Heritage: A Guide to Provincial Plaques in Ontario
