outh wind does not bring warmth enough to cause evaporation, whereas the coldness of the north wind concentrates the heat by a sort of recoil, so that there is more evaporation and not less. This is a thing which we can often observe in other places too. Wells, for instance, give off more vapour in a north than Brandon Saad Jersey in a south wind. Only the north winds quench the heat before any considerable quantity Naiset Nike Free 4.0 V2 of vapour has gathered, while in a south wind the evaporation is allowed to accumulate.
Water, once formed, does not freeze on the surface of the earth, in the way that it does in the region of the clouds.
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From the latter there fall three bodies condensed by cold, namely rain, snow, hail. Two of these correspond to the phenomena on the lower level and are due to the same causes, differing from them only in degree and quantity.
Snow and hoar-frost are one and the same thing, and so are rain and dew: only there is a great deal of the former and little of the latter. For rain is due to the cooling of a great amount of vapour, for the region from which and the time during which the vapour is collected are considerable. But of dew there is little: for the vapour collects for it in a single day and from a small area, as its quick formation and scanty quantity show.
The relation of hoar-frost and snow Salomon Quest 4D 2 Gore-Tex Kengät is the same: when cloud freezes there is snow, when vapour freezes there is hoar-frost. Hence snow is a sign of a cold season or country. For a great deal of heat is still present and unless the cold were overpowering it the cloud would not freeze. For there still survives in it a great deal of the heat which caused the moisture to rise as vapour from the earth.
Hail on the other hand is found in the upper region, Thomas Vanek Jersey but the corresponding phenomenon in the vaporous region near the earth is lacking. For, Mikhail Grigorenko Jersey as Canada Goose Hybridge Lite Kurtka we said, to Naiset Parajumpers Dodie 6 snow in the upper region corresponds hoar-frost in the lower, and to rain in the Bryan Little Jersey upper region, dew in the lower. But there is nothing here to correspond to hail in the upper region. Why this New Cardy Škornji 3177 is so will be clear when we have explained the nature of hail.
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But we must go on to collect the facts bearing on the origin of it, both those which raise no difficulties and those which seem paradoxical.
Hail Sweter is ice, and water freezes in winter; yet hailstorms Classic Short Sparkles 1002766 occur chiefly in spring and autumn and less often in the late summer, but rarely in winter and then only when the cold is less intense. And in general hailstorms occur in warmer, Henrik Lundqvist Jersey and snow in colder places. Again, there is a difficulty about water freezing in the upper region. It cannot have frozen before becoming water: and water cannot remain suspended in the air for any space of time. Nor can we say that the case is like that of particles of moisture which are carried up owing to their small size and rest on the iar (the water swimming on the air just as small particles of earth and gold often swim on water). In that case large drops are formed by the union of many small, and so fall down. This cannot take place in the case of hail, since solid bodies cannot clinks:
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