Secondly, In regard of the variation of the longitude of the Stars, we are to consider (what the Ancients observed not) that the site of the fixed Stars is alterable, and that since elder times they have suffered a large and considerable variation of their longitudes. [SN: _What the longitude of a Star is._] The longitude of a Star, to speak plainly, is its distance from the first point of numeration toward the East; which first point unto the Ancients was the vernal æquinox. Now by reason of their motion from West to East, they have very much varied from this point: The first Star of Aries in the time of _Meton_ the _Athenian_ was placed in the very intersection, which is now elongated and removed Eastward 28 degrees; insomuch that now the sign of Aries possesseth the place of Taurus, and Taurus that of Gemini. Which variation of longitude must very much distract the opinion of the Dog star; not only in our daies, but in times before and after; for since the World began it hath arisen in Taurus, and if the World last, may have its ascent in Virgo; so that we must place the canicular daies, that is, the hottest time of the year in the Spring in the first age, and in the Autumn in Ages to come. Thirdly, The Stars have not only varied their longitudes, whereby their ascents have altered; but have also changed their declinations, whereby their rising at all, that is, their appearing hath varied. [SN: _What the declination of a Star is._] The declination of a Star we call its distance from the Equator. Now though the Poles of the world and the Equator be immovable, yet because the Stars in their proper motions from West to East, do move upon the poles of the Ecliptick, distant 23 degrees and an half from the Poles of the Equator, and describe circles parallel not unto the Equator, but the Ecliptick; they must be therefore sometimes nearer, sometimes removed further from the Equator. All Stars that have their distance from the Ecliptick Northward not more then 23 degrees and an half (which is the greatest distance of the Ecliptick from the Equator) may in progression of time have declination Southward, and move beyond the Equator: but if any Star hath just this distance of 23 and an half (as hath Capella on the back of Ericthonius) it may hereafter move under the Equinoctial; and the same will happen respectively unto Stars which have declination Southward. And therefore many Stars may be visible in our Hemisphere, which are not so at present; and many which are at present, shall take leave of our Horizon, and appear unto Southern habitations. And therefore the time may come that the Dog star may not be visible in our Horizon, and the time hath been, when it hath not shewed it self unto our neighbour latitudes. So that canicular daies there have been none, nor shall be; yet certainly in all times some season of the year more notably hot then other.