Tuesday, July 12, 2011

2011 Streak Day 190/365: Canal Gates

2011 Streak Day 189/365 Walk - 2.36 miles, Time - 50min, Weather -still changeable

Today the photo is a cheat. I have gone back 5 days to when I was last by the canal to use this picture of swans diving for vegetation near a lock gate.
I know the plan was to take a picture on every outing but today there was a snag: the camera battery was flat. I could do nothing. At any other time when I would have gone out again and found something else to photo but today I did not feel like it. All I could do was an easy canal walk and that felt plenty hard enough.
However the picture does give me the opportunity to talk about V shaped canal gates, which are kept closed by the force of the water. When you see them in operation the principle looks so obvious that you imagine lock gates have been like that since the very first canal (longer ago than you think: 930 CE, in China) but no. The first locks had vertically lifting gates.
The current design is credited to Leonardo Da Vinci and can be seen in this drawing from his notebook. (This is the source of the illustration).

I really like the idea looking at the gates and thinking that they came from the same mind as pictures I can look at in art galleries.

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