Hydraulics.

4. But as this results from the diurnal Rotation ofthe Earth only, which is always uniform, and ever/where constantly the fame, it can cause no Alteration*in the Depth of the Water, in any particular Place*and therefore can have no Share in the Cause of th 6Flux and Reflux of the Sea, at least so little as not t0deserve Notice, and cannot be discern’d by the Senses*However, what that is will be shewn in the Sequel o»this Note.

5. The alternate Rising and Falling of the Wate rSis therefore owing to some other Cause or Causes th a’ 1what can be found in or upon the Earth ; that is, l£must be owing to some of the heavenly Bodies, whic^we fee at a Distance from us. This the Ancients mad®no Doubt of; and ascribed it to the Influence of th®Moon, with good Reason, as they saw so plain a Col 1 'gruity between the Motion of the Waters, and thatthe Moon. They could not also but observe, that a £each New and Full Moon the Tides were greater thahat other Times, and were therefore assured, thewas likewise concern’d in the Cause of the Tides. Y c3fPliny assures us, that they were so nice as to obsessthe annual Phuenomena of the Tide ; and knew that th®Tides were greater in Winter than in Summer. n uthey had no Theory to account for the diurnal, m el1 'strual, and annual Differences of the Tide. Thisreserv’d for the Invention of the celebrated Author ®our Philosophy, whose Footsteps, therefore, we st) 3 ^here insist on as near as possibly we can, in explicatesall the particular Phanomena of the Tides.

6. Since (as we have strewn) all Bodies mutually 3 *stract each other, the Moon at O will attract the E ar£at T, and its Waters, as well as be attracted by l£ 'But since the Law of Attraction is to decrease,the Squares of the Distances increase, the Water 3A, P, C, B, or at A, D, p, B, will be differedaffected by the attractive Power of the Moon, at K’the Attraction at A will be greatest as being neat? ’that at B least, and at C or D, it will be at a M® 3 ?’and the fame nearly as at T the Centre of the Ea rt J-becaufe of the very great Distance T O in respe$