This being Canada Day weekend, we start with a thoroughly Canadian topic - canoes. Collected Wisdom loves a canoe trip, especially as we have numerous minions to do that tiresome paddling bit.
THE QUESTION: Joanna Ranieri and Mark Hazelden of Toronto wonder why you steer a canoe from the back rather than the front.
THE ANSWER: "A canoe is one contiguous piece that pivots around its centre," writes Carolyn Pullen of Ottawa. The farther away from the pivot point that a stroke is made, the greater a turning effect it will have, she says. "Since the stern seat is farther from the pivot point than the bow seat (the bow seat is positioned to give enough leg room to the bow paddler), the stern paddler's strokes have a greater turning effect."
But Judith Skuce of Barrie, Ont., says both bow and stern paddlers have steering responsibilities. "In white-water paddling, it could be argued that the bow paddler has the greater responsibility to see obstacles and begin steering around them."
David Bird of Fernie, B.C., agrees. "A tandem canoe is properly steered by both the bow and stern paddlers." This is especially true in moving water where the goal of the paddle strokes is more often positioning the boat rather than simply propelling it forward.
However, he says that while bow and stern paddlers on flat water may expend the same amount of effort, the stern paddler will always overpower the bow paddler. This is because, "as the bow paddler moves into the most powerful part of his stroke, he has less and less water to work with" as his paddle moves toward the curve of the hull. In contrast, as the stern paddler moves into the powerful portion of his stroke, his paddle is moving away from the curve of the boat, and his unimpeded stroke is more efficient.
Traditionally, he says, this has been corrected by using the J-stroke. But a more efficient way of keeping a canoe going in a straight line is for the bow paddler to make an occasional draw stroke to bring the canoe back into line or for the paddlers to switch sides after every five or six strokes.
THE QUESTION: Why do bread crumbs last so long without going mouldy? Megan Walden of Port Credit, Ont., wants to know.
THE ANSWER: It's because mould needs moisture to grow, writes Julia English of Ottawa. "Breadcrumbs are typically very dry and this prohibits mould growth and spoiling. Bread, on the other hand, is quite moist and can develop mould relatively quickly."
HELP WANTED
Mark Chynoweth, who's currently working in Beijing, says he was recently struck by the title of the song The Times They Are A-Changing. He asks: "Is there some vestigial grammar construct or idiomatic phrasing, or even poetical metre that allows us to say things like 'a-changing' "?
Roy Overton of Sarnia, Ont., asks: Why do public washrooms have low urinals for little boys but no low washbasins?
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