Re: Armillary Dial

[SchaldachK]

In einer eMail vom 18.07.2005 22:07:09 Westeuropäische Sommerzeit schreibt [EMAIL PROTECTED]: Thank you all for a most enlightening tour through the centuries. Assuming then that the 'modern' pole style dial  with equal hours was an (Arabic?) innovation and perhaps an improvement over the nodus based  dial of antiquity,  what would have been the pre-requisite astronomical knowledge of the period to actually arrive at this new 'cutting edge' shadow clock with a gnomon pointing to the celestial north pole? Or was it perhaps initially merely a matter of trial and error until someone had pointed the gnomon in such a way that it read the hours consistently throughout the year? What had been the first, the hen or the egg, the equatorial dial for equal hours or the pole style dial? What I can say is: the first equatorial dial was an equal hour dial with a horizontal stick. It is no trial and error dial. And also another Greek one of around 100 before Christ (not yet published) for temporal hours was made very carefully and not by trial and error. Best wishes Karlheinz