The compass is another ancient Chinese invention, which shows the directions through the use of magnetic rock. The date of its invention is not certain, but it was believed to have been used for maritime navigation during the last years of the northern Sung dynasty (960-1126 A.D.).
與指南車原理不同，但同樣用來辨別方向的指南針，也是中國的一大發明，它利用磁性測定方位，雖然發明的年代無法確定，但早在北宋末期就已用於航海。當時海上交通很盛，商船穿梭於南海與阿拉伯海一帶。