1421: The Year The Chinese Discovered The World
"I could only shake my head in wonder at the skill and sophistication of these Chinese mariners of so many years ago. The Chinese astronomers' determination of the positions of Canopus and of the Southern Cross in the sky was a pivotal moment in the history of man's (sic) knowledge of the globe. Because they knew the circumference of the earth, they could calculate the true position of the South Pole. By observing the difference between the true bearing shown by the Southern Cross and that shown by their magnetic compasses, they could determine the position of the Magnetic South Pole and therefore make the necessary corrections to the positions of their compasses."
~Gavin Menzies, "The Voyage of Hong Bao; Voyage To Antarctica And Australia."1421: The Year The Chinese Discovered The World. p. 181 (2003).
bunk? possibly. but interesting, and nautical.