Down in the masonry valve chamber beneath the North Weir abutment, Master Mason Alden Bram could no longer see the horn lantern hanging on the far wall through the blinding white fog of scalding steam pouring up the vertical intake shaft.
He did not need the lantern to see the brass float-gauge bolted to the wet ashlar stones six inches from his face.
The copper counterweight-pointer—which had started at the chiseled numeral 7 two minutes ago when the fifth bell tolled—had slid down the graduated brass plate until its sharp bronze tip rested dead center on the thick horizontal bar of red raddle-chalk and the deep chisel-cut Alden had scored across the numeral 5.
Beneath the iron grating under Alden’s wooden-soled boots, the three-foot-thick limestone foundation blocks of the weir were vibrating like a taut saw-blade struck with a hammer. Down in the deep granite caverns under the Old Hill, the subterranean cooling reservoir of the Crown Furnace had boiled down to its last five minutes of water. Already, in the lower jacket where the cast-iron ribs of the ancient machine met the bedrock, dry pockets of red-hot metal were flashing the remaining water into high-pressure steam faster than the exhaust flues under Saint Jude’s crypt could vent it.
