From: utzoo!decvax!harpo!duke!mcnc!jwb
Newsgroups: net.physics
Title: Re: perpetual motion puzzle?
Article-I.D.: mcnc.1470
Posted: Mon Jan 17 10:37:02 1983
Received: Wed Jan 19 05:31:41 1983
References: fortune.726,sdcsvax.57

I have one of the clocks with the clear (glass in my case) which supports the
hands.  I found it in my parents' attic.  I have had to fix it several times so
I know how it works.  A regular clock motor is in the base. It has a conventional
gear.  Glued to the glass is a large gear hidden in the outer shell of the clock
It's sort of like a rack and pinion made into a circle.  Thus the entire glass
rotates.  The minute hand travels through friction with the glass.  It's not
rigid so you can set the clock.  The hour hand is connected through a series
of gears with a weight so it achieves a virtual movement which corresponds to
1/60 the speed of the minute hand.  This may be more than anyone wanted to
know, but it is how it works.

Jack Buchanan