Entering Entry hall 738: The Munitions Smithy, Qiao Ming and Yan Zhiqiu stepped into a heavy-duty workshop purpose-built for the high-speed manufacture of heavy siege ammunition. The room was ventilated by high, narrow smoke-chimney pipes cut into the ceiling, housing a backup earth-heat crucible fire, two heavy cast-iron pouring tables, and rows of machined steel projectile molds.
Along the eastern wall sat wooden racks filled with pre-cut billets of star-fallen iron, salvaged from the lower foundries during their ascent. Beside them were copper crates containing hundreds of stamped glowing-bronze stabilizing fins, threaded base-caps, and hardened chert projectile tips designed to shatter solid rock upon impact.
Qiao Ming set down his coil of star-thread line upon a clean wooden bench. He approached the backup fire, which was connected to the same earth-heat magma chimney pipe that powered the High Anvil of Entry hall 720. He used a long bronze key. He turned the chimney pipe valve, allowing a small diversion stream of fiery gas to circulate through the firebrick chamber. Within minutes, the inside of the fire glowed with intense, orange-gold heat.
He loaded an eighty-pound graphite crucible with chopped billets of star-fallen iron. That added measured scoops of limestone flux and copper melted rock waste to purge any surface rusting. He swung the crucible into the fire chamber using the balanced overhead hoist. He watched the dark metal soften and collapse into a dazzling, liquid pool of sky steel.
