The balance weight shaft inside the eastern pylon of Sluice Nine was an upright chimney of dressed grey granite, sixteen arm-lengths square and two hundred arm-lengths deep. He dropped straight down into the lightless bedrock of the world.
Qiao Ming stood upon the suspended upkeep cradle seventy feet below the overhead frame floor.
The cradle—a platform of thick oak planks slung from four heavy bronze chains—swayed gently in the damp updraft that blew continuously from the lower water tanks. The air in the shaft was freezing. It smelled of cold lead, wet stone dust, and the dark, stone grease used to lubricate the upright guide-channels. Above him, through the square opening of the overhead frame hatch, the yellow light of his horn lantern looked like a distant, solitary star.
Hanging in the center of the shaft, suspended by two titanic glowing-bronze chains whose links were as thick as tree trunks, was the main eastern balance weight.
It was a huge metal tube of cast lead, twelve feet in width and twenty feet tall, weighing four hundred tons. The lead was dull grey, scratched and pitted by hundreds of years of upright travel, bearing the cast seal of the Second Master of Works across its curved waist.
