Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/385

 Page 358 the first was tenebrous: whereupon that which happened before concerning the differences of dayes and nights, touching the dayes being greater or lesser than the nights, now falls out quite contrary. And first, we see, that whereas in the first Figure the circle IK was wholly in the light, it is now wholly in the dark; and the opposite arch LM is now wholly in the light, which was before wholly in the dark. Of the parallels between the grand circle CD, and the Pole A, the semidiurnal arches are now lesser than the seminocturnal, which before were the contrary. Of the others likewise towards the Pole B, the semidiurnal arches are now bigger than the seminocturnal, the contrary to what happened in the other position of the Earth. We now see the Sun made vertical to the inhabitants of the Tropick GN, and to be depressed towards the South, with those of the Parallel EF, by all the arch ECG, that is, 47 degrees; and in summe, to have passed from one to the other Tropick, traversing the Equinoctial, elevating and declining in the Meridians the said space of 47 degrees. And all this mutation is derived not from the inclination or elevation of the Earth, but on the contrary, from its not inclining or elevating at all; and in a word, by continuing always in the same position, in respect of the Universe, onely with turning about the Sun situate iu the midst of the said plane, in which it moveth it self about circularly with its annual motion. And here is to be noted an admirable accident, which is, that like as the Axis of the Earth conserving the same direction towards the Universe, or we may say, towards the highest Sphere of the fixed stars, causeth the Sun to appear to elevate and incline so great a space, namely, for 47 degrees, and the fixed Stars to incline or elevate nothing at all; so, on the contrary, if the same Axis of the Earth should maintain it self continually in the same inclination towards the Sun, or, if you will, towards the Axis of the Zodiack, no mutation would appear to be made in the Sun about its elevating or declining, whereupon the inhabitants of one and the same place would alwayes have one and the same difference of dayes and nights, and one and the same constitution of Seasons, that is, some alwayes Winter, others alwayes Summer, others Spring, &c. but, on the contrary, the alterations in the fixed Stars would appear very great, as touching their elevation, and inclination to us, which would amount to the same 47 degrees. For the understanding of which let us return to consider the position of the Earth, in its first Figure, where we see the Axis AB, with the superiour Pole A, to incline towards the Sun; but in its third Figure, the same Axis having kept the same direction towards the highest Sphere, by keeping parallel to it self, inclines no longer towards the Sun with its superiour Pole A, but