David C. Roy makes wind-up sculptures out of wood that do really cool moiré effects and move in hard-to-predict ways. The gallery has Flash demos of what they look like in motion, and a few Quicktimes. The most surprising thing about these is that they all seem to run for six to twelve hours on a single winding!

Which brings us to Arthur Ganson, who makes somewhat louder, but still slow, sculptures out of motors and gears. Machine with Concrete is one of the cooler ones: the motor turns the first geat at 212 RPM, but after twelve 1/50th gear reductions, the final gear turns one revolution ever two trillion years, at which time it will presumably have shattered the concrete block in which it's embedded. Quicktime here.

That's longer than the Clock of the Long Now, but Machine with Concrete will need two trillion years worth of gasoline...