The passage opened into an avenue so vast that the yellow light of their horn lantern died against the air before striking the distant flanking walls. Here, in Entry hall 653, the massive master builders of the Second Epoch had abandoned the human scale entirely. Flanking a central roadway paved with corrugated iron flags, huge cog-towers rose like dark rock cliffs into the darkness, their sheer mass dominating the underground horizon.
Qiao Ming walked barefoot along the crown of the roadway, his calloused soles gripping the raised chevron tread of the iron plates. On either side, giant stone waterwheels sixty arm-lengths in width stood suspended over dry water chutes of dressed granite. Their paddles, crafted from layered copper plates two spans thick, were crusted with thick crusts of dark green rust and hardened barnacle shells from the first cosmic drowning. Above each wheel, an epicyclic gear train rose in staggered tiers, teeth as broad as dining tables locked irrevocably into one another.
Behind him, Yan Zhiqiu paused before the base of the fourth cog-tower, her fingers tracing the huge bronze bearing-block that supported the main axle. The axle itself was a solid metal tube of cold-rolled star-fallen iron, four paces in outer rim, resting in an oil-cup lined with babbit metal. The lubricating animal fat had turned to crumbly yellow wax thousands of years ago, preserving the polished surface of the spindle in a tomb of dead grease.
