Dear Willy, Gianni, Kevin, Brad, Harold and all other interested dialists,
Thank you for all the nice suggestions. I will try to incorporate them in my
explorations.
My vertical sun dial measures 128 cm x 231 cm. The top of the gnomon comes 26,5
cm before the table. During 216 days of sun shine between January 22, 2008 and
August 3, 2010 I did 1.015 observations. ( 4 or 5 times per day of sun shine).
The following mean errors were found:
1. Hour of the day: 0'49"
2. Day of the year: 1,3 days
3. Longitude of the sundial: 0°0,6'
4. Latitude of the sundial: 0°6,0'
5. Equation of time: less than 40 seconds
6. Solar declination: <0,5°
7. Vernal equinox: 1:52' hour
8. Summer solsice: 4:18 hour
9. Autumn equinox: 1:06' hour
10. Winter solstice: 2:32' hour
11. Aphelion: 1:56' hour
12. Excentricity: less than 2% ( mean e value = between 0,0167 and 0,0169)
13. Length of the tropical year: 1:09' hour
Off course, these are mean values of the error. The individual observations
were often less precise.
It was a fascinating job. And it is still going on.
Jos Kint
50°59'N
3°39'E
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