Hai Collection, Upper Volume Radical: Horse (mǎ) Si (a team of four horses); Kangxi strokes: 15; Page 1437, Entry 01 Pronounced si (falling tone) According to the Yupian (Jade Chapters), it refers to four horses drawing a single carriage. In the commentary on the poem "Liang Ma Wu Zhi" from the Book of Odes (Shijing), Wang Su states: In ancient times, a carriage with a single shaft used three horses and five reins. The Xia dynasty used two horses, called li. The Shang dynasty added one outer horse, called can. The Zhou dynasty added another outer horse, called si. Si means four horses to a carriage; the two in the middle are called fu, and the two on the sides are called can. Dong states: Horses between the shafts are called fu, and those on the outer sides of the shafts are called can. Also, according to the Zuo Zhuan (Zuo's Commentary), in the eleventh year of Duke Wen, Fufu Zhongsheng rode in a four-horse chariot. Also, according to the Hanshu (Book of Han), in the treatise on the suburban sacrifices, the Qin dynasty sacrificed at the four altars (si zhi), each altar using four wooden dragons and one set of wooden chariot and horses (four horses), each colored according to the emperor being worshipped. The annotation by Li Qi says: Yu means to entrust; it means entrusting the form of a dragon to wood. Shigu says: One si means four dragons. Also, the name of a constellation. According to the Erya (Approaching Elegance), the Celestial Si is the Room asterism (Fang su). The annotation says: The Room asterism consists of four stars, which is why it is called the Celestial Si. Also, a place name. According to the Hanshu (Book of Han), in the Geography section, there is a Siwang County in Langya Commandery. Also, a Siwang County in Lelang Commandery. Also, a surname. According to the Zuo Zhuan (Zuo's Commentary), in the tenth year of Duke Ding, the master builder of Hou was named Si Chi. Also, according to the Hanshu (Book of Han), in the annals of Emperor Wen, the uncle of the King of Qi was named Si Jun. Also, used as a phonetic loan for the character for four. In the Book of Rites (Liji), regarding music, it mentions "striking four times," which refers to awe-inspiring power. The annotation says: Here, the character si should be read as four. Each performance symbolizes four strikes; one strike and one pierce is called one fa. Also, pronounced xi (falling tone). The meaning is the same. Correction: In the reference to the Book of Odes (Shijing), the text regarding the can and zou horses has been checked. The commentary by Wang Su is found in the sub-commentary to the "Gan Mao" section of the "Odes of Yong," not in the "Lesser Odes." Following the original text, the seven characters referring to the "Lesser Odes" have been corrected to read "Sub-commentary on the Odes of Yong, Liang Ma Wu Zhi."