The acid-burning geyser at Borehole Four had showed two undeniable facts to Giles Croft.
First, the deep underground strata below Haven-Hold were rich in earth-heat energy and boiling stone underground water beds. Second, any human being who tried to dig down without positive-pressure air breath flow would die of hydrogen sulfide poisoning within forty seconds.
“The air down there’s five percent acid vapor and ninety percent unbreathable choke-damp,” Giles told the assembly of guild masters gathered in the planning shed.
On the drafting table lay his newest large-scale height drawing: a sixteen-foot width upright shaft lined with segmented cast-iron rings, piercing three thousand feet into the mountain’s root.
Lady Millicent Croft sat at the corner of the long timber bench, her brass-cornered ledger open before her. She dipped her iron nib into black ink, recording the supply order numbers with brisk smooth speed.
“One hundred and forty tons of cast-iron tubbing segments,” Millicent said, her tone dry and measured. “Eight hundred bags of slaked burning lime powder from the lower valley kilns.
And twenty-four experienced steam-fitter apprentices reassigned from the river wharves. Giles, if this upright chimney pipe fails to draw, we will have sunk three months of foundry surplus into an empty chimney.”
