The Rideau Canal winds roughly two hundred kilometres through eastern Ontario, connecting the city of Ottawa with Kingston on the shore of Lake Ontario. It was emphatically not constructed for pleasure. Amid the anxious years following the War of 1812, British authorities feared that hostilities with their neighbours to the south might resume. They wanted a secure supply route that would circumvent the dangerously exposed St. Lawrence River. Lieutenant-Colonel John By, a British military engineer, was entrusted with the enterprise, and construction extended from 1826 until 1832. The labour proved gruelling. A considerable number of the labourers who excavated the channel by hand succumbed to a fever, in all likelihood malaria, that swept through the work camps each summer.
Rather than excavate a single deep trench across the countryside, By embraced an ingenious "slackwater" approach. Dams were erected along existing rivers and lakes to inundate shallow stretches to a navigable depth. A succession of stone locks then conveyed vessels up and down the numerous variations in elevation. Forty-seven locks were constructed altogether. Remarkably, the great majority are still cranked open and shut manually today, employing substantially the same mechanism the original crews installed. That circumstance renders the canal an exceptional working museum of nineteenth-century engineering.
