The South Pointing Chariot
The south-pointing chariot device was first invented by the Chinese mechanical engineer Ma Jun (c. 200-265 AD). It was a wheeled vehicle that incorporated an early use of differential gears to operate a fixed figurine that would constantly point south, hence enabling one to accurately measure their directional bearings. This effect was achieved not by magnetics (like in a compass), but through intricate mechanics, the same design that allows equal amounts of torque applied to wheels rotating at different speeds for the modern automobile. After the Three Kingdoms period, the device fell out of use temporarily. However, it was Zu Chongzhi who successfully re-invented it in 478 AD, as described in the texts of the Song Shu (c. 500 AD) and the Nan Chi Shu, with a passage from the latter below:
When Emperor Wu of Liu Song subdued Guanzhong he obtained the south-pointing carriage of Yao Xing, but it was only the shell with no machinery inside. Whenever it moved it had to have a man inside to turn (the figure). In the Sheng-Ming reign period, Gao Di commissioned Zi Zu Chongzhi to reconstruct it according to the ancient rules. He accordingly made new machinery of bronze, which would turn round about without a hitch and indicate the direction with uniformity. Since Ma Jun's time such a thing had not been.
Read more about this topic: Zu Chongzhi
Famous quotes containing the words south, pointing and/or chariot:
“Indeed, I believe that in the future, when we shall have seized again, as we will seize if we are true to ourselves, our own fair part of commerce upon the sea, and when we shall have again our appropriate share of South American trade, that these railroads from St. Louis, touching deep harbors on the gulf, and communicating there with lines of steamships, shall touch the ports of South America and bring their tribute to you.”
—Benjamin Harrison (1833–1901)
“The young ... look into visages dull-eyed, long-toothed, wattle-necked, and chop-fallen, something they have never been and which they cannot imagine ever being.... If it occurs to a young person, looking at us, that this is the direction in which he himself travels, how can he forgive, let alone bear the sight of, us, who constantly bring him the bad news of our own faces, bitter signposts pointing to his own destination?”
—Jessamyn West (1902–1984)
“Whose starward eye
Saw chariot “swing low”? And who was he
That breathed that comforting, melodic sigh,
“Nobody knows de trouble I see”?”
—James Weldon Johnson (1871–1938)