“Double dawn”eclipse and the rotational variation of the earth
“Double dawn” eclipse and the rotational variation of the earth

A record of “double dawn” at State Zheng in the first year of the reign of King Yi in Western Zhou Dynasty in the chronicle “Bamboo Annals” (Zhushu Jinian) is discussed. We think that it may be a record of an annular solar eclipse happening in 899 BC. The record and the T, which describes the secular variation of the earth’s rotation, are analyzed and discussed.