276 Mathematical Elements Book IV.

like to what we have demonstrated elsewhere con-*1174 cerning Heat*.

1409 If now we consider the Luminaries recedingfrom the Plane of the Equator, we shall perceivethat the Agitation is diminifh’d, and becomes le/s,according as the Declination of the Luminaries becomesgreater ; which plainly appears, if we conceivethem to be in the Poles, for then the Axis of thespheroidical Figure coincides with the Action ofthe Earth; and all the Lections that are parallelto the Equator, are perpendicular to the Axis ofthe Spheroid, and therefore circular ; so that theWater in every Circle of Latitude will have everywhere the fame Elevation ; and so in the Motionof the Earth, the height of the Sea is not chang’din particular Places. If the Luminaries recedefrom the Poles, it is easy to find that the Agita-tion will be more and more increas’d, till it bethe greatest of all, the Spheroid revolving abouta Line perpendicular to the Axis, the Axis ofthe Spheroid being supposed in the Plane of theEquator.

1410 Hence it is plain, why in the Syzygics, mar theEquinoxes, the Tides are obferv'd to be the greatest ,'both Luminaries being in or near the Equator.

14x1 The Adiions of the Moon and Sun are greater, the*1354 lest those Bodies are distant from the Earth* ; but*1390 when the Distance of the Sun is less, and it is &the South Signs,often both the greatest equinoctialTides are observ’d in that Situation of the Sun »that is, before the vernal, and after the autumnalEquinox, which yet does not happen every Teat,because some Variation may arise from the Situa-tion of the Moon’s Orbit, and the distance of tn eSyzygy from the Equinox.

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