The ferryman's hefty Africans pace short reciprocating arcs on the deck, sweeping and shoveling the black water of the Charles Basin with long stanchion-mounted oars, minting systems of vortices that fall to aft, flailing about one another, tracing out fading and flattening conic sections that Sir Isaac could probably work out in his head. The Hypothesis of Vortices is pressed with many difficulties. The sky's a matted reticule of taut jute and spokeshaved tree-trunks. Gusts make the anchored ships start and jostle like nervous horses hearing distant guns. Irregular waves slap curiously at the lapping clinkers of their hulls, which are infested with barefoot jacks paying pitch and oakum into troublesome seams. The ships appear to glide this way and that as the ferry's movement plays with the parallax. Enoch, who has the good fortune to be a bit taller than most of the other passengers, hands the reins to Ben and excuses his way around the ferry's deck trying to read the names.