3. He pretends, that all Rivers proceed from a _Colluvies_ or _Rendevous_ of Rain-waters, and that, as the Water, that falls upon _Hills_, gathers more easily together, than that which falls in _Plaines_, therefore it is, that Rivers ordinarily take their Source from _Hills_. Thence also comes it (saies he) that there are more _Rivers_, than _Torrents_, in the _Temperate Zones_; and, on the contrary, more _Torrents_, than _Rivers_, in the _Torrid Zone_: For, as in hot Climats the Mountains are far higher, the Water, that descends from them with impetuosity, runs away in a little while, and formes such Collections of Water, as soon dry up, but in cold Climats, the Waters do not run away but slowly, and are renew'd and recruited by Rain, before they are quite dryed up; because the Hills are there lower, and so the Bed of Rivers hath lesse declivity. Having thus discoursed of _Rivers_ in _General_, he treats of the _Nile_ in _particular_; and there 1. Observes, That the Order of the Seasons of the Year is quite inverted under the _Torrid Zone_. For, whereas it should be then Summer, when the Sun is near; and Winter, when the Sun is farther off: Under the _Torrid Zone_ 'tis never lesse hot, than when the Sun is nearest; nor more hot, than when the Sun is farthest off: So that to the people that live between the _AEquinoctial_ and the _Tropicks_, Summer begins about _Christmass_, and their Winter, about St. _Johns_ day. The reason whereof is, (_saith he_) that when the Sun is directly over their Heads, it raises abundance of vapors, and draws them so high, that they are presently converted into Water by the coldnesse of the Air; whence it comes to passe, that then it rains continually, which does refresh the Air; but when the Sun is farther off, there falls no more rain, and so the Heat becomes insupportable. 2. He proves by many recent Relations, that the _Sources_ of the _Nile_ are on this side of the _AEquinoctial_ in _AEthiopia_, of which he gives a very accurate _Mappe_, correcting many faults which _Geographers_ are wont to commit in the Description of the Kingdom of the _Abyssins_, which they believe to be much greater than indeed it is. {306} 3. This supposed, he easily gives an account, why the _Nile_ yearly overflows about the end of _June_: For, as at that time there falls much rain in _AEthiopia_, it must needs be, that the _Nile_, whose source is in that Country, should then overflow, when those rains begin, and subside, when they cease. There are besides, in this Book, two other _Tracts_. In the _first_, M. _Vossins_ endeavours to maintain the Doctrine, he had deliver'd in his Book _De Lumine_, and to shew, that the _Soul_ of Animals is nothing but _Fire_, that there are no invisible Atoms; nor so much as any Pores, even in the Skin of man. Here he treats also of _Refractions_, and alledges the Examples of several persons, who have then seen the Sun by the means of Refraction, when really He was under the _Horizon_.