ObjID131-1
‹ Ancient Sundials
Dialface ID 129
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Abstract
Gibbs: The base and left half are broken away from this example.
Measurements
Measurement record: pipeline ObjID 131, matched to this dialface by inventory number.
| Quality grade | A (completeness 78 %) |
|---|---|
| Dial surface | cone (decisive) · fit residual mm: cone 0.27, cylinder 1.21, sphere 3.72 |
| Latitude φ | 35.88 ± 0.49° (single witness: path-III-front-back) |
| Engraved lines | 7 hour lines, 3 day lines |
| Cone half-angle α | 31.1 ± 0.34° (cone residual on all points 0.28 mm) |
| Measured | 2026-06-12 20:18 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 30.4° | 54.1° | 77.8° |
| Noon shadow (gnomon heights) | 1.70 | 0.72 | 0.22 |
| Length of the day | 9.5 h | 12.0 h | 14.5 h |
| Length of a seasonal hour | 48 min | 60 min | 72 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
- – Deonna, Waldemar, Le mobilier délien, Paris, 1938, p. 191, figure 225.
- – Gibbs, Sharon L., Greek and Roman Sundials, New Haven and London, 1976, p. 249.
3D Models
