Let the ecliptic ♎ ♑ ♈ ♋ (in fig. 5) be divided into four equal parts by the two strait lines _a b_ and ♑ ♋, cutting one another at right angles in the centre _c_. And taking the arch _b d_ of two degrees and sixteen minutes, let the strait line _d e_ be drawn parallel to _a b_, and cutting ♑ ♋ in _f_; which being done, the eccentricity of the earth will be _c f_. Seeing therefore the annual motion of the earth is in the circumference of an ellipsis, of which ♑ ♋ is the greater axis, _a b_ cannot be the lesser axis; for _a b_ and ♑ ♋ are equal. Wherefore the earth passing through _a_ and _b_, will either pass above ♑, as through _g_, or passing through ♑, will fall between _c_ and _a_; it is no matter which. Let it pass therefore through _g_; and let _g l_ be taken equal to the strait line ♑ ♋; and dividing _g l_ equally in _i_, _g i_ will be equal to ♑ _f_, and _i l_ equal to _f_ ♋; and consequently the point _i_ will cut the eccentricity _c f_ into two equal parts; and taking _i h_ equal to _i f_, _h i_ will be the whole eccentricity. If now a strait line, namely, the line ♎ _i_ ♈, be drawn through _i_ parallel to the strait lines _a b_ and _e d_, the way of the sun in summer, namely, the arch ♎ _g_ ♈, will be greater than his way in winter, by 8¼ degrees. Wherefore the true equinoxes will be in the strait line ♎ _i_ ♈; and therefore the ellipsis of the earth's annual motion will not pass through _a_, _g_, _b_, and _l_; but through ♎, _g_, ♈ and _l_. Wherefore the annual motion of the earth is in the ellipsis ♎ _g_ ♈ _l_; and cannot be, the eccentricity being salved, in any other line. And this perhaps is the reason, why Kepler, against the opinion of all the astronomers of former time, thought fit to bisect the eccentricity of the earth, or, according to the ancients, of the sun, not by diminishing the quantity of the same eccentricity, (because the true measure of that quantity is the difference by which the summer arch exceeds the winter arch), but by taking for the centre of the ecliptic of the great orb the point _c_ nearer to _f_, and so placing the whole great orb as much nearer to the ecliptic of the fixed stars towards ♋, as is the distance between _c_ and _i_. For seeing the whole great orb is but as a point in respect of the immense distance of the fixed stars, the two strait lines ♎ ♈ and _a b_, being produced both ways to the beginnings of Aries and Libra, will fall upon the same points of the sphere of the fixed stars. Let therefore the diameter of the earth _m n_ be in the plane of the earth's annual motion. If now the earth be moved by the sun's simple motion in the circumference of the ecliptic about the centre _i_, this diameter will be kept always parallel to itself and to the strait line _g l_. But seeing the earth is moved in the circumference of an ellipsis without the ecliptic, the point _n_, whilst it passeth through ♎ ♑ ♈, will go in a lesser circumference than the