All these things would regularly come to pass, if the whole Earth were cover'd with Sea very deep; but by reason of the shoalness of some places, and the narrowness of the Streights, by which the Tides are in many cases propagated, there arises a great diversity in the Effect, and not to be accounted for, without an exact Knowledge of all the Circumstances of the Places, as of the Position of the Land, and the Breadth and Depth of the Channels by which the Tide flows; for a very slow and imperceptible Motion of the whole Body of the Water, where it is (for Example) 2 Miles deep, will suffice to raise its Surface 10 or 12 Feet in a Tides time; whereas, if the same quantity of Water were to be convey'd up a Channel of 40 Fathoms deep, it would require a very great Stream to effect it, in so large Inlets as are the Channel of _England_, and the _German_ Ocean; whence the Tide is found to set strongest in those places where the Sea grows narrowest; the same quantity of Water being to pass through a smaller Passage: This is most evident in the _Streights_, between _Portland_ and _Cape de Hague_ in _Normandy_, where the Tide runs like a Sluce; and would be yet more between _Dover_ and _Calais_, if the Tide coming about the Island from the North did not check it. And this force being once impress'd upon the Water, continues to carry it above the level of the ordinary height in the Ocean, particularly where the Water meets a direct Obstacle, as it is at St. _Malo's_; and where it enters into a long Channel, which running far into the Land, grows very streight at its Extremity; as it is in the _Severn-Sea_ at _Chepstow_ and _Bristol_. This shoalness of the Sea, and the intercurrent Continents are the reason, that in the open Ocean the time of High water is not at the Moons appulse to the Meridian, but always some Hours after it; as it is observ'd upon all the West Coast of _Europe_ and _Africa_, from _Ireland_ to the _Cape of Good Hope_: In all which a S. W. Moon makes High-water, and the same is reported to be on the West side of _America_. But it would be endless to account all the particular Solutions, which are easie Corollaries of this _Hypothesis_; as why the _Lakes_, such as the _Caspian Sea_, and _Mediterranean Seas_, such as the _Black Sea_, the _Streights_ and _Baltick_, have no sensible Tides: For _Lakes_ having no Communication with the Ocean, can neither increase nor diminish their Water, whereby to rise and fall; and Seas that communicate by such narrow Inlets, and are of so immense an Extent, cannot in a few Hours time receive or empty Water enough to raise or sink their Surface any thing sensibly.