ObjID499-1
‹ Ancient Sundials
Dialface ID 542
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Abstract
Information on the Dialface ID 542 / Object ID 499
Measurements
Measurement record: pipeline ObjID 499, matched to this dialface by inventory number.
| Quality grade | B (completeness 100 %) |
|---|---|
| Dial surface | cone (decisive) · fit residual mm: cone 0.79, cylinder 4.03, sphere 4.01 |
| Latitude φ | 36.52 ± 2.22° (consensus of witnesses) |
| Klima | Rhodes (IV), Delos, Athens |
| Engraved lines | 11 hour lines, 3 day lines |
| Cone half-angle α | 34.9 ± 0.10° (cone residual on all points 0.8 mm) |
| Measured | 2026-06-12 20:50 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 29.8° | 53.5° | 77.2° |
| Noon shadow (gnomon heights) | 1.75 | 0.74 | 0.23 |
| Length of the day | 9.5 h | 12.0 h | 14.5 h |
| Length of a seasonal hour | 47 min | 60 min | 73 min |
Computed for the measured latitude with the obliquity of the JPL ephemeris at 101 BC (year -100). The latitude is the one the dial was made for, not a find-spot coordinate.
References
3D Models
