The heat in the lower lehr gallery of Salt Ward was dry, choking, and smelled of molten borax, burnt sulfur, and charred pine shavings. For sixty years, these vaulted brick halls had served as the heavy-duty heart of the northern glass trade. Here, beneath forty-foot arches blackened by ages of bituminous coal smoke, the great annealing kilns had run day and night, cooling lenses for the royal navy and thick bottle-glass for the capital breweries.
Now, under the emergency lamps of the coalition, the kilns had completed their most dangerous heat. Forty-eight hours of nonstop, unrushed cooling for the stone armor of the broken-sun brake.
Melli Dorn wiped her soot-streaked forehead with a damp linen rag, her leather apron crackling stiffly. She stepped between the twin rows of glowing annealing ovens. Around her, twenty master glassmakers in thick sheepskin mitts and heavy felt aprons were carefully easing the final heat absorption panels from the cooling racks.
These were not ordinary window panes, and they weren’t the brittle bottle-glass blown in the town factories. They were three-inch-thick massive stone slabs of hardened heat-proof glass salt-glass, exactly six feet long and three feet wide, formulated with powdered bitter salt, copper oxide, and crushed quartz dust quartz. They had been heat-softened for seventy-two hours under controlled heat drops to withstand the ferocious infrared blast wave of the solar discharge without undergoing explosive heat shattering.
