'The water is like the Cœlestial Æther, a fluid medium through which all things move. Cape Cod, over yonder, is like the distant, fixed stars – by sighting that church-steeple in Provincetown, the High Land of Cape Cod to the south of it, the protruding mast of yonder wrack, and then by doing a bit of trigonometry, we may plot our position, and by joining one point to the next, draw our trajectory. The schooner, then, is like a comet – also moving through the æther – but by measuring the angles she makes with us and with the church-steeple, et cetera, we may find her true course; compare it with her apparent heading; and easily judge whether she is, or is not, leewardly.'