佛祖歷代通載 2.23

2.23

(Jiazi 1) Feng Hou established the sexagenary cycle (jiazi) (another version says Da Nao. Thirty-eight years after the Emperor ascended the throne, he first ordered Da Nao to create the sexagenary cycle; hence the thirty-eighth year was taken as the first jiazi, and calculating backward to his first year yields the year dinghai). Rong Cheng created the calendar; Lishou calculated arithmetic. He inquired into the Way from Guangchengzi. Cangjie served as scribe; Qibo distinguished herbs and plants; Yu Fu determined the Pulse Classic; Ling Lun fashioned the pitch-pipes (to harmonize the musical pitch-pipes, bamboo tubes nine cun long were used, either decreased or increased to determine the five tones). He established the Nine Provinces (the Li di ji says: 'The Yellow Emperor had twenty-five sons, twelve of whom received surnames: Ji, You, Qi, Yi, Teng, Zhen, Ren, Xun, Xi, Shi, Huan, and Xiu. He divided them to govern the Nine Provinces: Ji, Qing, Xu, Yu, Yong, Liang, Chu, Yang, and Yan. From the eldest to the youngest, they were enfiefed in order. Later, the descendants—the Five Emperors and Three Kings—were all their posterity.' The Emperor married a daughter of Dating Shi and had two sons: the elder was named Xuanxiao, and the younger was named Changyi). Altogether eighteen generations, lasting 1,520 years.