ObjID298-1
‹ Ancient Sundials
Dialface ID 340
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Abstract
Information on the Dialface ID 340 / Object ID 298
Measurements
Measurement record: pipeline ObjID 298, matched to this dialface by inventory number.
| Quality grade | B (completeness 75 %) |
|---|---|
| Dial surface | cone (preferred, not decisive) · fit residual mm: cone 0.53, cylinder 0.54, sphere 2.20 |
| Latitude φ | 30.35 ± 0.64° (single witness: path-III-front-back) |
| Engraved lines | 5 hour lines, 3 day lines |
| Cone half-angle α | 19.1° (cone residual on all points 0.56 mm) |
| Measured | 2026-06-12 20:40 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 35.9° | 59.6° | 83.4° |
| Noon shadow (gnomon heights) | 1.38 | 0.59 | 0.12 |
| Length of the day | 10.0 h | 12.0 h | 14.0 h |
| Length of a seasonal hour | 50 min | 60 min | 70 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. 22 f.
3D Models
