Overview
Key data
| Item | Detail |
|---|---|
| Author | Li Chunfeng (602–670) |
| Completed | Early Tang (finished in a yisi year, hence the title) |
| Volumes | Ten |
| Contents | Classed prognostications: stars, weather, wind, sun and moon |
The origin of the title
“Yisi” is a year in the sexagenary cycle; the work was finished in a yisi year and takes its name from it.
Naming a book after the year of its completion was not uncommon, and this is a notable instance.
Contents and form
The work is arranged by class, setting out earlier prognostications class by class: on the sky, on the sun and moon, on the five planets,
on weather, and on the “wind angles,” each with the views of earlier writers and his own judgement.
Li Chunfeng also compiled the Linde calendar and was a leading calendrical scholar of the Tang;
the astronomical statements in the book rest on the astronomy of his day, so that its astronomical material is reliable apart from the prognostications.
Value
The Yisi Zhan preserves a great deal of earlier divination literature, much of it otherwise lost.
For the study of astral divination and astronomical knowledge before the Tang it is a principal source.
The divination texts quoted in Tang and Song encyclopaedias can often be collated against it.
Compiled and arranged by Chujia Kuang.