Hello All, I think Mike nailed it, as to what Ken is asking. I know of no sundial, other than Mike's here, that directly measures the Eot, rather than somehow incorporate the EoT calculated elsewhere. I did not think this was possible until I saw Mike's solution just now, because a sundial has no way of measuring Mean Solar Time without a previously calculated EoT chart. In Tom Hank's movie Cast Away, he records an analemma on a cave wall, but this is movie fiction. His watch was broken and he had no way to measure mean time, only local solar time. -Bill
On Sun, Feb 3, 2013 at 5:51 PM, <jmikes...@ntlworld.com> wrote: > Ken, > > I think I made a device some time ago to do what you want . > > A cylinder was tilted to the appropriate latitude angle and direction. > There was a small hole on one side of the cylinder which gave a projected > a spot of light from the sun on the inner opposite surface where there was > a graph which showed: > left to right – the equation of time > up and down – the sun’s declination. > > The cylinder was driven round using a 24 hour clock motor, so the spot of > light remained apparently stationary except for changes in the EoT and > sun’s declination that were read directly from the graph. > > Sadly, I don’t think I have it any more. > > Mike Shaw > 53º 22' North 03º 02' West > www.wiz.to/sundials > > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2013.0.2897 / Virus Database: 2639/6076 - Release Date: 02/02/13 > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > >
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