Now of these two, although the first in some latitude may be retained, yet is not the other in any to be admitted. For in regard of time (as we elsewhere declare) the stars do vary their longitudes, and consequently the times of their ascension and descension. That star which is the term of numeration, or point from whence we commence the account, altering his site and longitude in process of time, and removing from West to East, almost one degree in the space of 72 years, so that the same star, since the age of _Hippocrates_ who used this account, is removed in _consequentia_ about 27 degrees. Which difference of their longitudes, doth much diversifie the times of their ascents, and rendereth the account unstable which shall proceed thereby. Again, In regard of different latitudes, this cannot be a setled rule, or reasonably applied unto many Nations. For whereas the setting of the Pleiades or seven stars, is designed the term of Autumn, and the beginning of Winter; unto some latitudes these stars do never set, as unto all beyond 67 degrees. And if in several and far distant latitudes we observe the same star as a common term of account unto both, we shall fall upon an unexpected, but an unsufferable absurdity; and by the same account it will be Summer unto us in the North, before it be so unto those, which unto us are Southward, and many degrees approaching nearer the Sun. For if we consult the Doctrine of the sphere, and observe the ascension of the Pleiades, which maketh the beginning of Summer, we shall discover that in the latitude of 40, these stars arise in the 16 degree of Taurus; but in the latitude of 50, they ascend in the eleventh degree of the same sign, that is, 5 dayes sooner; so shall it be Summer unto _London_, before it be unto _Toledo_, and begin to scorch in _England_, before it grow hot in _Spain_. This is therefore no general way of compute, nor reasonable to be derived from one Nation unto another; the defect of which consideration hath caused divers errors in Latine poets, translating these expressions from the _Greeks_; and many difficulties even in the _Greeks_ themselves; which living in divers latitudes, yet observed the same compute. So that to make them out, we are fain to use distinctions; sometime computing cosmically what they intended heliacally: and sometime in the same expression accounting the rising heliacally, the setting cosmically. Otherwise it will be hardly made out, what is delivered by approved Authors; and is an observation very considerable unto those which meet with such expressions, as they are very frequent in the poets of elder times, especially _Hesiod_, _Aratus_, _Virgil_, _Ovid_, _Manilius_; and Authors Geoponical, or which have treated _de re rustica_, as _Constantine_, _Marcus Cato_, _Columella_, _Palladius_ and _Varro_.