LIKE A GOOD C ARTESIAN who measures everything against a fixed point, Daniel Waterhouse thinks about whether or not to go back to England while keeping one eye, through a half-closed door, on his son: Godfrey William, the fixed stake that Daniel has driven into the ground after many decades' wanderings. At an arbitrary place on a featureless plain, some would argue, but now the Origin of all his considerations. Sir Isaac would have it that all matter is a sort of permanent ongoing miracle, that planets are held in their orbits, and atoms in their places, by the immanent will of God, and looking at his own son, Daniel can hardly bear to think otherwise. The boy's a coiled spring, the potential for generations of American Waterhouses, though it's just as likely he'll catch a fever and die tomorrow.