Its central stem is an air pressurized tube with three openings at different distances from the clock face and that rotate about the stem at different speeds.
Opposite each opening is a windsock. The opening that rotates fastest, blows into a long, thin windsock, the second hand. The opening that rotates slowest, blows into a short, thick windsock, the hour hand.
The clock face is concave along its perimeter to direct the flow of air away from the ceiling/wall.-- FarmerJohn, Jun 18 2005 Wind Sock Clock http://www.bathyform.com/HB/airclock.htmlApologies to anyone using dial-up - I wanted to learn how to do video... [moomintroll, Jun 19 2005] nothing to do with steenky socks then.-- po, Jun 18 2005 will it make cappuccino froth in my wellies?-- benfrost, Jun 18 2005 <linky> A bit rough and ready, but I'm learning all the time!-- moomintroll, Jun 19 2005 Wow, what a fantastic clip, [moomintroll]. It took me a few seconds to see that the right-hand edge is nearest the viewer.-- FarmerJohn, Jun 19 2005 Hmm.. yes, I see what you mean [FJ]. Next time I'll try and stick a bit more background context in. Glad you liked it, though - it was a great training exercise :)-- moomintroll, Jun 19 2005 Nice. +-- sartep, Jun 19 2005 Brilliant - I'd never seen this before, but bonus points to [moom] for the realisation.-- zen_tom, Dec 03 2009 random, halfbakery