Sir Isaac Newton has determined from the Theory of Gravity that the difference of the lengths of Pendulums at the Equator and the Pole is 1,919 lines. But M. De La Place from a comparison of the actual lengths of pendulums found by observation at 10 different places, and admitting (with Newton) the Earth to be a regular Spheroid, makes that differenc 2,438 lines, and at the mean Latitude of 45 the Pendulum = 440.519 lines, Therefore in other Latitudes the lengths will be as follows