 The method used was block printing.The scientist, statesman, and general Shen Kuo (1031–1095 AD) was the author of the "Dream Pool Essays" (1088), a large book of scientific literature that included the oldest description of the magnetized compass.During the Song Dynasty, there was also the enormous historical work of the "Zizhi Tongjian", compiled into 294 volumes of 3 million written Chinese characters by the year 1084 AD.