297. Suppose now there is a number of bodies, as _A_, _B_, _C_, _D_, _E_, _F_, _G_, _H_ placed round _O_, so as to form a flexible or fluid ring: then, as the whole is attracted towards _M_, the parts at _H_ and _D_ will have their distance from _O_ increased; whilst the parts at _B_ and _F_, being nearly at the same distance from _M_ as _O_ is, these parts will not recede from one another; but rather, by the oblique attraction of _M_, they will approach nearer to _O_. Hence, the fluid ring will form itself into an ellipse _ZIBLnKFNZ_, whose longer Axis _nOZ_ produced will pass through _M_, and it’s shorter Axis _BOF_ will terminate in _B_ and _F_. Let the ring be filled with bodies, so as to form a flexible or fluid sphere round _O_; then, as the whole moves toward _M_, the fluid sphere being lengthned at _Z_ and _n_, will assume an oblong or oval form. If _M_ is the Moon, _O_ the Earth’s center, _ABCDEFGH_ the Sea covering the Earth’s surface, ’tis evident by the above reasoning, that whilst the Earth by it’s gravity falls toward the Moon, the Water directly below her at _B_ will swell and rise gradually towards her: also, the Water at _D_ will recede from the center [strictly speaking, the center recedes from _D_] and rise on the opposite side of the Earth: whilst the Water at _B_ and _F_ is depressed, and falls below the former level. Hence, as the Earth turns round it’s Axis from the Moon to the Moon again in 24-3/4 hours, there will be two tides of flood and two of ebb in that time, as we find by experience. [Sidenote: Fig. II.]