The pine drafting table in the center of the Old Ferry warehouse was covered with sheets of heavy rag paper, covered in dense columns of exact counts written in black dark oak-ink. Senior Surveyor Korr Var sat on a high stool, his horn-rimmed glasses resting on his nose, an ivory-and-brass rolling parallel rule in his left hand and a fine steel dip-pen in his right. Beside him sat a pot of boiled tea and a half-eaten sourdough crust, cold and forgotten in the intensity of the work.
Pella stood beside him. She held Hal Rook’s grease-pencil ferry logs and a set of trigonometric tables. Outside, the autumn rain fell with increasing violence, drumming against the cedar shingles and sending muddy streams of water gurgling through the cobbled gutters toward the river. The damp chill of wet stonework seeped in through the warehouse walls. He carried the sharp, bitter silt stench of the harbor mudflats.
“Equation One: The Dynamic Head Equation,” Korr Var said, writing out the algebraic terms with sharp, deliberate strokes. “H-sub-d equals speed squared over two times the gravity constant, plus static depth, plus the friction loss along the granite invert. In Hal Rook’s notes, the speed term was calculated for smooth-flowing open-channel flow. But when Sorell sealed the Third Gate, he converted a free-surface gravity channel into a high-pressure channel.”
