ObjID311-1
‹ Ancient Sundials
Dialface ID 353
Page 1 of 6
Abstract
Information on the Dialface ID 353 / Object ID 311
Measurements
Measurement record: pipeline ObjID 311, matched to this dialface by inventory number.
| Quality grade | B (completeness 99 %) |
|---|---|
| Dial surface | cone (decisive) · fit residual mm: cone 0.44, cylinder 3.07, sphere 4.82 |
| Latitude φ | 43.87 ± 1.70° (consensus of witnesses) |
| Klima | Massalia, Mid-Pontus (VI), Rome |
| Engraved lines | 10 hour lines, 3 day lines |
| Cone half-angle α | 30.0 ± 0.06° (cone residual on all points 0.46 mm) |
| Measured | 2026-06-12 20:42 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 22.4° | 46.1° | 69.8° |
| Noon shadow (gnomon heights) | 2.42 | 0.96 | 0.37 |
| Length of the day | 8.7 h | 12.0 h | 15.3 h |
| Length of a seasonal hour | 43 min | 60 min | 77 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. 44.
3D Models
