"All Plymouth is made up of the results of pilgrimage. How many scores of fathoms deep the real Plymouth shore lies I do not know. It is down there somewhere where it cooled into bathylithic crust back in the gray dawn of time when the earth was made. There it is part of the same ledge of which Scituate and Cohasset are built. All above that is terminal moraine, rock detritus piled upon rock foundation by the glacier. Plymouth Rock itself thus came joy riding from some ledge up Boston way, alighting from this first and greatest New England Transportation System only a few hundred thousand years before Mary Chilton arrived to set foot upon it."