Chuck
Senior Member
You can tell that Markham and Vaughan Townships were laid out differently at the Town Line (Steeles) as you can easily tell the shifts in Bathurst Street and Kennedy Road, for example.
Scarborough was laid out differently as well - you can tell by the shifts in Finch and Sheppard.
The kinks in concession roads are a result of the manner in which the roads were originally surveyed 200+ years ago, not due to municipal boundaries which came later. Proper surveying practice, especially before digital equipment was introduced, was to stake out a grid box by box, rather than just going off for miles at a time in straight lines. This procedure ensures that concessions are not only straight, but parallel, because the surveying procedure includes the measurement of precise angles. This is also why the concession grid appears to consist of individual stacks of boxes, rather than a perfect checkerboard.
Now for some Toronto concession trivia: the standard surveying unit 200 years ago was called the chain. A standard acre is defined by a rectangle measuring 1 by 10 chains in size. Say you laid 100 such rectangles side by side, and stacked 10 of these strips on top of each other. You would now have a box measuring 100 by 100 chains, and containing exactly 1000 acres. This is the logic behind Toronto's concessions - they are exactly 100 chains apart, and enclose exactly 1000 acres.
1 chain measures 66 feet in length, therefore 100 chains measure 6600 feet. Convert to metric, and our concessions are 1980 metres apart, which conveniently equals about 2 km. This concession style is repeated in many rural areas throughout Ontario, including downtown Toronto, North York, most of York Region, Oakville, Burlington, and much of Ottawa. Scarborough, Etobicoke, and Peel use a different system.