From: utzoo!decvax!decwrl!sun!megatest!fortune!kiessig Newsgroups: net.physics Title: Re: perpetual motion puzzle? Article-I.D.: fortune.731 Posted: Mon Jan 17 13:59:35 1983 Received: Thu Jan 20 05:12:18 1983 References: utah-gr.686 I guess they could rotate the whole plastic box. The clocks I saw were square, though. Perhaps rotating a round piece of plastic inside the square? There certainly weren't any gear teeth visible. Rick Kiessig {harpo,megatest}!fortune!kiessig