China, which is about five thousand miles across, was difficult to map because of its vast dimension, yet the Song Dynasty Map of 1137 a. d. shows the big rivers of China and their tributaries with amazing accuracy, far greater than what could have been achieved with merely a compass and the path of the sun, and with that accuracy of measure demonstrated, very interesting is that the eastern Asia ocean shoreline is shown a hundred miles east of where today, the Ice Age shoreline, the source map for the Song Dynasty map therefore drawn during the Ice Age.
