Book IV. of Natural Philosophy. 2J§

to the Increase of the Gravity of the Water onthe Earth’s Surface, in Places Which are 90 Deg.distant from the Sun (from the fame Action ofthe Sun) as 60 i to 1 * ; therefore this Increase of *1288the Gravity is to the Gravity of the Water as 1 to38605679. The Diminution of the Gravity un-der the Sun, and in the opposite Place, is doublethis Increase*; therefore it is to the Gravity as 1 *1296to 1930839; and the whole Change th the Gravity 1417arising from the Action of the Sun , is to the Gravityitself aS 1 to 12868560.

Ih order to compare the Action of the l^oon 14*8with the Action of the Sun, We must make Ex-periments in Places, in which, by reason of theNarrowness, the Sea is sensibly raised. Near Bri-stol, at the Autumn and Spring, at which Timesthe Agitation of the Sea is greatest*, the Water *1410ascends in the Syzygies about 45 Feet, more orless; in the Quadratures about 25 Feet, moreor less; which Numbers are to one another as 9to 4.

The Determination of the Forces, which wewould find, if the greatest and least Elevationswere exactly at the Time of the Syzygies, wouldbe very easy, which we have shewn before not tohappen so*. *1408

The distance of the Moon from the Syzygy orthe Quadrature is not always the fame in thegreatest or least Elevation, for this distance varies,because the Moon is sometimes more, and some-times less distant from the Meridian, When it goesthro’ the Syzygy or Quadrature; the mean di-stance of the Moon from the Syzygy or Quadra-ture, to which the aforesaid Observations oughtto be referr’d, is about 18 Deg. 30 Min. so thatthe whole Action of the Sun neither conspireswith the Action of the Moon in the Syzygies,hor acts contrary to it in the Quadratures; also

T 4 ist