梦溪笔谈
Later on in the Song dynasty the compass was used with maritime navigation. Several decades after the "Wujing Zongyao" was written, the scientist and statesman Shen Kuo (1031–1095 AD) wrote of the first truly magnetized compass needle in his book "Dream Pool Essays" (1088 AD). With a more efficient compass magnetized by lodestone, the thermoremanence compass fell out of use. The later maritime author Zhu Yu wrote of the magnetic needle compass as a means to navigate at sea in his "Pingzhou Table Talks" of 1119 AD.