Incoming email from recent prolific commenter here Russell Whitaker (his blog Survival Arts is now on the blogroll to your left):

Today’s . . .

. . . i.e. Saturday‘s . . .

. . . featured pic on WikiPedia, seems up your alley.

Indeed it is.  What a fascinating object.  I had no idea that such things even existed.  This one reminds me vaguely of the front of a combine harvester.

The Falkirk Wheel, named after the nearby town of Falkirk in central Scotland, is a rotating boat lift connecting the Forth and Clyde Canal with the Union Canal, which at this point differ by 35 metres in height.

It consists of two diametrically opposed caissons which always weigh the same whether or not they are carrying their capacity of 600 tonnes of floating canal barges. According to Archimedes’ principle floating objects displace their own weight in water. This keeps the wheel balanced and so, despite its enormous mass, it rotates through 180° in less than four minutes while using very little power.

One of the nice things, if you think about it, about engineering things of this kind is that if is often quite hard to tell at a glance when they were built.  After all, what does the job does the job, no matter when.  Anyway, it turns out that this Falkirk Wheel is very recent, having been opened only in 2002.

Lottery money.  If they have to waste public money, this is definitely how to do it.

Wonderful.  And wonderful Wikipedia.  Thanks Russell.