hat determine different savours. But these have been explained in another treatise.
We have now given an account of waters and the sea, why they persist, how they change, what their nature is, and have explained most of their natural operations and affections.
4
Let us proceed to the theory of winds. Its basis is a distinction we have already made. We recognize two kinds of evaporation, one moist, the other dry. The former is called vapour: for the other there is no general name but we must call it a sort of smoke, applying to the whole of it a word that is proper to one of its forms. The moist cannot exist without the dry nor the dry without the moist: whenever Moncler Lapset we speak of Moncler Takit Miehet either we mean that it predominates. Now when the sun in its circular Leicester City Trøjer course approaches, it draws up by its heat the moist evaporation: when Miehet Northface Realization Takki it recedes the cold makes the vapour that had been raised condense back into water which falls and is distributed through the earth. (This explains why there is more rain in winter and more by night than by day: though the fact is not Deportivo La Coruna recognized because rain by night is more apt to escape observation than by day.) But there is a great quantity of fire and heat in the earth, and the sun not only draws up the moisture that lies on the surface of it, but warms and dries the earth Miehet Northface Down Takki itself. Consequently, since there are two kinds of evaporation, as we have said, one like vapour, the other like smoke, both of them are Grækenland Fodboldtrøjer necessarily generated. That in which moisture predominates is the source of rain, as we explained before, while the dry evaporation is Singapore Fodboldtrøjer the source and substance of all winds. That things must necessarily take this course is clear from the resulting phenomena themselves, for the evaporation that is to produce them must necessarily differ; and the sun and the warmth in the earth not only can but must produce these evaporations.
Since the two evaporations are specifically distinct, wind and rain obviously differ and their substance is not the same, as those say who maintain that one and the same air Colombia Børn Fodboldtrøjer when in motion is wind, but when it condenses again is water. Air, as we have explained in an earlier book, is made up of these as constituents. Vapour is moist and cold (for its fluidity is due to its Eindhoven moistness, and because it derives from water it is naturally cold, like water that has not been Moncler Untuvatakki Miehet warmed): whereas the smoky evaporation is hot and dry. Hence each contributes a part, and air is moist and hot. It is absurd that this air that surrounds us should become wind when in motion, whatever be the source of its motion on the contrary the case of winds is like that of rivers. We do not call water that flows anyhow a river, even if there is a great quantity of it, but only if the flow comes from a spring. So too with the winds; a great quantity of air might be moved by the fall of some large object without flowing from any source or spring.
The facts bear out our theory. It is because the evaporation takes place Puola Pelipaidat uninterruptedly but differs in degree and quantity that clouds and winds appear in their natlinks:
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