Again, Were the day definitive, it had prevented the delusion of the devil, nor could he have gained applause by its prediction; who notwithstanding (as _Athanasius_ in the life of _Anthony_ relateth) to magnifie his knowledge in things to come, when he perceived the rains to fall in _Æthiopia_, would presage unto the _Egyptians_ the day of its inundation. And this would also make useless that natural experiment observed in earth or sand about the River; by the weight whereof (as good Authors report) they have unto this day a knowledge of its encrease. Lastly, It is not reasonable from variable and unstable causes, to derive a fixed and constant effect, and such are the causes of this inundation, which cannot indeed be regular, and therefore their effects not prognosticable like Eclipses. For depending upon the clouds and descent of showers in _Æthiopia_, which have their generation from vaporous exhalations, they must submit their existence unto contingencies, and endure anticipation and recession from the movable condition of their causes. And therefore some years there hath been no encrease at all, as some conceive in the years of Famin under _Pharaoh_, as _Seneca_, and divers relate of the eleventh year of _Cleopatra_; nor nine years together, as is testified by _Calisthenes_. Some years it hath also retarded, and came far later then usually it was expected, as according to _Sozomen_ and _Nicephorus_ it happened in the days of _Theodosius_; whereat the people were ready to mutiny, because they might not sacrifice unto the River, according to the custom of their Predecessors. Now this is also an usual way of mistake, and many are deceived who too strictly construe the temporal considerations of things. Thus books will tell us, and we are made to believe that the fourteenth year males are seminifical and pubescent; but he that shall enquire into the generality, will rather adhere unto the cautelous assertion of _Aristotle_, that is, _bis septem annis exactis_, and then but _magna ex parte_. That Whelps are blind nine days, and then begin to see, is generally believed, but as we have elsewhere declared, it is exceeding rare, nor do their eye-lids usually open until the twelfth, and sometimes not before the fourteenth day. And to speak strictly, an hazardable determination it is unto fluctuating and indifferent effects, to affix a positive Type or Period. For in effects of far more regular causalities, difficulties do often arise, and even in time it self, which measureth all things, we use allowance in its commensuration. Thus while we conceive we have the account of a year in 365 days, exact enquirers and Computists will tell us, that we escape 6 hours, that is a quarter of a day. And so in a day which every one accounts 24 hours, or one revolution of the Sun, in strict account we must allow the addition of such a part as the Sun doth make in his proper motion, from West to East, whereby in one day he describeth not a perfect Circle.