ObjID166-1
‹ Ancient Sundials
Dialface ID 165
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Abstract
A complete bronze gnomon remains in a lead-filled hole in the top surface of the dial. Lion legs and feet flank the base of this dial. A relief margin outlines the edges of the dial at the sides. Within the margin is a relief consisting of a calyx, from which sprouts a stem ending in a second calyx. Eleven hour lines cross three day curves but do not extend beyond either solstice.
Measurements
Measurement record: pipeline ObjID 166, matched to this dialface by inventory number.
| Quality grade | B (completeness 99 %) |
|---|---|
| Dial surface | cone (decisive) · fit residual mm: cone 0.42, cylinder 3.31, sphere 4.24 |
| Latitude φ | 37.56 ± 1.71° (consensus of witnesses) |
| Klima | Delos, Athens, Rhodes (IV) |
| Engraved lines | 10 hour lines, 3 day lines |
| Cone half-angle α | 35.7 ± 0.12° (cone residual on all points 0.43 mm) |
| Measured | 2026-06-12 20:26 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 28.7° | 52.4° | 76.2° |
| Noon shadow (gnomon heights) | 1.82 | 0.77 | 0.25 |
| Length of the day | 9.4 h | 12.0 h | 14.6 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
- – Gibbs, Sharon L., Greek and Roman Sundials, New Haven and London, 1976, p. 285.
- – Mauri, Amedeo, Pompeii, Rome, 1970, p. 147, plate 33 (photograph of dial in position).
- – Severino, Nicola, De Monumentis Gnomonicis apud graecos et romanos. Le meridiane greco-romane. La storia, il catalogo, gli articoli, Roccasecca, 2003, p. 18.
- – Warscher, Tatiana, I marmi di Pompei, 1948, no. 263.
3D Models
