On a river boat knots mark depth ‘tween fix and set for dead reckoning to the river bottom, and further reckoning of speed in knots and of turbidity in the brown water of amphibious craft. Namely, the historic riverboats of Mark Twain in the Mississippi and, landing craft and ships of class LCM, LST, LPD and LSD. Samuel Clemens’s stories of the Muddy Mississippi explain names like LSD 47 “The Gator”.
And, thus, though more complicated, is the same premise for inclination towards stellar evidences and the thence approximate derivations of the Newtonian vortice scholiums. Marking distance ‘tween set and fix, dead reckoning to heaven, proximal to you, Cecilia. I love you.