The fourth stroke fell, and the four-hundred-and-thirty-two-cycle master chord ignited.
All three hundred statues along the Grand Row of pillars sang together in total, divine all at once. The sound energy of three hundred hollow Carrara and hard speckled rock cores merged into a single, cohesive blast wave that did not travel through the air. But flashed through the six-foot dark rock wall like an electric discharge.
The moving feedback exited the outer face of the Great Iron Arch in an invisible, bone-shaking wave of pure sound.
The effect on the abandoned machinery in the outer gatehouse was total.
The four heavy air-powered star drills, embedded in the cured magnetic iron mortar, shattered at the same time. Their heavy dark metal-hardened carbon-iron bits exploded into thousands of harmless grey pebbles. Their cast-iron cylinders cracked along their seams with sharp, ringing concussions like pistol shots. The backup steam pool on the air pump carriage burst with an ear-splitting CRACK, blowing its bronze safety valves twenty arm-lengths into the ceiling vaults.
Qiao Ming brought his Folded brass star-compass to the port to measure the feedback impact.
The tracking data showed that every piece of clockwork siege equipment in Entry hall 350 had been crushed into inert scrap. The high-pressure air-powered hazard was fully removed. The solid strength of the hard speckled rock columns was one hundred percent preserved.
