Overview
Key data
| Item | Detail |
|---|---|
| Excavated | 1977, Shuangudui tomb 1, Fuyang, Anhui |
| Period | Emperor Wen of Han |
| Object | Lacquered wooden discs, two stacked and rotatable |
| Faces | Upper disc with the mansions’ measures; lower disc with the degrees of the circle |
| Also called | Called in the literature the “round table of the twenty-eight mansions” or “astronomical disc” |
Structure and use
The disc has two layers that can be turned against each other. The upper carries the names and measures of the twenty-eight mansions; the lower the degrees of the circuit.
Turning the upper layer sets the mansions against the degrees, giving each mansion’s direction and extent.
It is a working instrument, not an ornament.
The measures of the mansions
The measures cut on the disc can be compared with those in transmitted texts such as the “Treatise on Pitch Pipes and the Calendar” of the Han shu.
Set against one another, they show how the mansions’ measures were distributed in the Han.
Value
Surviving Chinese astronomical instruments are mostly of the Song and later; Han objects are rare.
This disc is a rare physical Han instrument, and its find alongside the Fuyang astrological slips makes the two corroborate each other.
Compiled and arranged by Chujia Kuang.