Dear Bob, Mac et al That is indeed a nice article...
> http://www.timezone.com/library/rdnotebook/200503287777 ... but at $275,000 a time, I don't think I shall be rushing out to buy one of these watches while stocks last. I like the epicyclic drive, a delightfully simple way to add the equation of time to the time shown by the minute hand. There are, though, limitations in the use of a kidney-shaped cam... One problem is that the cam has to go round once per tropical year and the mechanism for getting that right is not explained. Another problem is that the Equation of Time is not static. It is continuously changing and the fixed shape of the kidney does not allow for this. Arguably the most ambitious mechanical clock is that of Jens Olsen in Copenhagen. This tracks the precession of the equinoxes and if he gets that right he may have attended to the consequential changes to the Equation of Time too. Frank King --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
