Adam Clarke Bible Commentary

Hitherto shalt thou come - Thus far shall thy flux and reflux extend. The tides are marvellously limited and regulated, not only by the lunar and solar attractions, but by the quantum of time also which is required to remove any part of the earth's surface from under the immediate attractive influence of the sun and moon. And this regulation takes place by means of the rotation of the earth round its own axis, which causes one thousand and forty-two miles of its equator to pass from under any given point in the heavens in one hour; and about five hundred and eighty miles in the latitude of London: so that the attracted fluid parts are every moment passing from under the direct attractive influence, and thus the tides cannot generally be raised to any extraordinary height. The attraction of the sun and moon, and the gravitation of its own parts to its own center, which prevent too great a flux on the one hand, and too great a reflux on the other; or, in other words, too high a tide, and too deep an ebb, are also some of those bars and doors by which its proud waves are stayed, and prevented from coming farther; all being regulated by these laws of attraction by the sun and moon, the gravitation of its own parts from the sun and moon, and the diurnal motion round its own axis, by which the fluid parts, easily yielding to the above attraction, are continually moving from under the direct attractive influence. Here a world of wisdom and management was necessary, in order to proportion all these things to each other, so as to procure the great benefits which result from the flux and reflux of the sea, and prevent the evils that must take place, at least occasionally, were not those bars and doors provided. It is well known that the spring-tides happen at the change and full of the moon, at which time she is in conjunction with and opposition to the sun. As these retire from their conjunction, the tides neap till about three days after the first quadrature, when the tides begin again to be more and more elevated, and arrive at their maximum about the third day after the opposition. From this time the tides neap as before till the third day after the last quadrature; and afterwards their daily elevations are continually increased till about the third day after the conjunction, when they recommence their neaping; the principal phenomena of the tides always taking place at or near the some points of every lunar synodic revolution.