ObjID313-1
‹ Ancient Sundials
Dialface ID 355
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Abstract
Sei linee orarie visibili. Equinozi e solstizi. L´incavo per lo gnomone e parte del basamento.
Measurements
Measurement record: pipeline ObjID 313, matched to this dialface by inventory number.
| Quality grade | B (completeness 79 %) |
|---|---|
| Dial surface | sphere (decisive) · fit residual mm: cone 2.99, cylinder 12.49, sphere 1.47 |
| Latitude φ | 28.21 ± 0.84° (single witness: hours-SuSo-regression) |
| Engraved lines | 7 hour lines, 3 day lines |
| Cone half-angle α | not shown: surface fit decisively sphere: cone-specific quantities do not apply |
| Measured | 2026-06-12 20:42 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 38.1° | 61.8° | 85.5° |
| Noon shadow (gnomon heights) | 1.28 | 0.54 | 0.08 |
| Length of the day | 10.2 h | 12.0 h | 13.8 h |
| Length of a seasonal hour | 51 min | 60 min | 69 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
- – Severino, Nicola, De Monumentis Gnomonicis apud graecos et romanos. Le meridiane greco-romane. La storia, il catalogo, gli articoli, Roccasecca, 2003, p. 45.
3D Models
