ObjID71-1
‹ Ancient Sundials
Dialface ID 67
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Abstract
Gibbs: A hole at the junction of the summer solstice and the meridian, 11 mm x 10 mm and 18 mm deep, connects via a trough with the lower edge of the spherical surface. Also, there is evidence of a groove and a depression in the top surface of the monument above the meridian on the dial surface. A spherical depression in this large hexagonal monument has been marked for use as a sundial.
Measurements
Measurement record: pipeline ObjID 71, matched to this dialface by inventory number.
| Quality grade | B (completeness 87 %) |
|---|---|
| Dial surface | sphere (decisive) · fit residual mm: cone 2.72, cylinder 2.72, sphere 0.81 |
| Latitude φ | 14.81 ± 2.41° (consensus of witnesses) |
| Klima | Meroe (I) |
| Engraved lines | 9 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 21:01 |
What the dial shows at this latitude
| Winter solstice | Equinox | Summer solstice | |
|---|---|---|---|
| Noon altitude of the Sun | 51.5° | 75.2° | 81.1° |
| Noon shadow (gnomon heights) | 0.80 | 0.26 | 0.16 |
| Length of the day | 11.1 h | 12.0 h | 12.9 h |
| Length of a seasonal hour | 56 min | 60 min | 64 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
- – Clermont-Ganneau, Charles, Recueil d'Archéologie Orientale Vol. I, Paris, 1888, p. 48.
- – Gibbs, Sharon L., Greek and Roman Sundials, New Haven and London, 1976, p. 180.
- – Healey, John F., A Nabataean Sundial from Mada'in Salih, 1989, p. 334 ff.
3D Models
