The mud in the bottom of the eastern trench had begun to stiffen into a sticky, gray clay as the bypass drainage pumps pulled the water level down to the gravel invert. The air between the narrow granite walls was cool and damp. It carried the heavy silt stench of river mud, the sharp bitter-salt dust of pipe lime flaking from the older Roman stonework. The oily smell of boiled animal fat being smeared over the screw threads of Eren Tal’s heavy iron lifting jacks.
Ada Morland was kneeling at the very toe of the northern timber shoe, her steel-rimmed glasses pushed up on her forehead and her cheek pressed tight against the cold wooden earpiece of her brass sounding rod. Her left hand held an eight-ounce brass machinist’s hammer, with which she gently tapped the granite foundation stone six inches below the timber seat.
Tink. Clonk.
Ada shifted the rod three inches to the left, tapping again. Tink. Hollow, dragging hum.
‘Listen to this, Eren,’ Ada called out. She gestured for the master wheelwright to kneel beside her in the muck. ‘Hear that backup echo? That isn’t solid bedrock under this footing. There is a level void three feet wide running right beneath this pier.’
