sun will appear in _s_. Wherefore the true place of the sun will be in _t_, that is to say, without the centre of the earth's annual motion by the quantity of the sine of the arch _a r_, or the sine of two degrees and 16 minutes. Now this sine, putting 100,000 for the radius, will be near 3580 parts thereof. And so much is the eccentricity of the earth's annual motion, provided that that motion be in a perfect circle; and _s_ and _r_ are the equinoctial parts. And the strait lines _s r_ and _c a_, produced both ways till they reach the zodiac of the fixed stars, will fall still upon the same fixed stars; because the whole orb _a b c d_ is supposed to have no magnitude at all in respect of the great distance of the fixed stars. Supposing now the sun to be in _c_, it remains that I show the cause why the earth is nearer to the sun, when in its annual motion it is found to be in _d_, than when it is in _b_. And I take the cause to be this. When the earth is in the beginning of Capricorn at _b_, the sun appears in the beginning of Cancer at _d_; and then is the midst of summer. But in the midst of summer, the northern parts of the earth are towards the sun, which is almost all dry land, containing all Europe and much the greatest part of Asia and America. But when the earth is in the beginning of Cancer at _d_, it is the midst of winter, and that part of the earth is towards the sun, which contains those great seas called the South Sea and the Indian Sea, which are of far greater extent than all the dry land in that hemisphere. Wherefore by the last article of chapter XXI, when the earth is in _d_, it will come nearer to its first movent, that is, to the sun which is in _t_; that is to say, the earth is nearer to the sun in the midst of winter when it is in _d_, than in the midst of summer when it is in _b_; and, therefore, during the winter the sun is in its _Perigæum_, and in its _Apogæum_ during the summer. And thus I have shown a possible cause of the eccentricity of the earth; which was to be done.