_B._ The necessity of the obliquity of the ecliptic is but a consequence to the precession of the equinoctial points. And therefore, if from C, the north pole, you make a little circle, C _u_, equal to fifteen minutes of a degree upon the earth, and another, _u s_, equal to the same, which will appear like this figure 8, that is, (as Copernicus calls it), a circle twined, the pole C will be moved half the time of the equinoctial points, in the arc C _u_, and as much in the alternate arc _u s_ descending to _s_. But in the arc _s u_, and its alternate rising to C, the cause of the twining is the earth’s annual motion the same way in the ecliptic, and makes the four quarters of it; and makes also their revolution twice as slow as that of the equinoctial points. And, therefore, the motion of it is the same compounded motion which Copernicus takes for his supposition, and is the cause of the precession of the equinoctial points, and consequently of the variation of the obliquity, adding to it or taking from it somewhere more, somewhere less; so as that one with another the addition is not much more, nor the subtraction much less than thirty minutes. But as for the natural efficient cause of this compounded motion, either in the sun, or the earth, or any other natural body, it can be none but the immediate hand of the Creator. _A._ By this it seems that the poles of the earth are always the same, but make this 8 in the sphere of the fixed stars near that which is called Cynosura. _B._ No: it is described on the earth, but the annual motion describes a circle in the sphere of the fixed stars. Though I think it improper to say a sphere of the fixed stars, when it is so unlikely that all the fixed stars should be in the superficies of one and the same globe. _A._ I do not believe they are. _B._ Nor I, since they may seem less one than another, as well by their different distances, as by their different magnitudes. Nor is it likely that the sun (which is a fixed star) is the efficient cause of the motion of those remoter planets, Mars, Jupiter, and Saturn; seeing the whole sphere, whose diameter is the distance between the sun and the earth, is but a point in respect of the distance between the sun and any other fixed star. Which I say only to excite those that value the knowledge of the cause of comets, to look for it in the dominion of some other sun than that which moveth the earth. For why may not there be some other fixed star, nearer to some planet than is the sun, and cause such a light in it as we call a comet? _A._ As how? _B._ You have seen how in high and thin clouds above the earth, the sun-beams piercing them have appeared like a beard; and why might not such a beard have appeared to you like a comet, if you had looked upon it from as high as some of the fixed stars?