XVII.
Fair Weather for a Week, with a Southern Wind, is like to produce a great Drought, if there has been much Rain out of the South before. The Wind usually turns from North to South, with a quiet Wind without Rain, but returns to the North, with a strong Wind and Rain; the strongest Winds are when it turns from South, to North by West.
N. B. When the North Wind first clears the Air (which is usually once a Week) be sure of a fair Day or two.
OBSERVATIONS of this Nature upon Winds have employed the ablest Heads in all Ages. Pliny the great Naturalist has left us a great deal upon this Subject, which plainly proves that it has been the Opinion of the ablest and wisest Men that Study and Experience might reduce even Things of such seeming Incertainty under stated Rules, and within the Bounds of a regular System. For Instance he tells us.
"IN Africa the South Wind is serene, the North East cloudy. All the Winds have their Turns. To judge rationally of their Changes, the fourth Day of the Moon is to be regarded.—The South Wind blows stronger than the North East, because the former rises from the Bottom, whereas the latter comes from the Surface of the Sea. It is for this Reason that those Earthquakes are most dangerous that follow after a South Wind."
IN order to understand this Notion of Pliny, we need only advert to the Account given us by the Reverend Mr. Robinson, in his natural History of Westmoreland, which is exceedingly curious, and well worthy of the Reader's perusal. This ingenious Gentleman is of Opinion that Winds have their original from the Sea, of which he gives the following very probable Account.
"IT, that is, the Wind, proceeds from vast swarms of nitrous Particles arising from the Bottom of the Sea, which being put into Motion, either by the central Fire, or by the Heat and Fermentation which abound in this great Body of the Earth; and therefore the first Commotion excited by the said Fermentation, we call a Bottom Wind, which is presently discovered by Porpusses and other Sea Fish, which delight in sporting and playing upon the Waves of the Sea, and by their playing give the Mariners the first Notice of an approaching Storm.
"WHEN these nitrous swarms are risen towards the Surface of the Sea in a dark Night, they cause such a shining light upon the Waves, as if the Sea was on fire. And being delivered from the brackish Water, and received into the open Air, those fiery and shining Meteors which fix upon the Masts and Sides of the Ships, and are only nitrous particles condensed by the circumambient Cold, and like that which the Chymists call Phosphorus, or artificial Glow-worm, shine and cast a Light but have no Heat: This gives the Mariners the second Notice that the Storm is rising, for upon the first breaking out of the Wind, the Sea begins to be rough, and the Waves swell and rise, when at the same time the Air is calm and clear.
"THIS boiling Fermentation of the Sea causes the Vapours to rise, which by the Intenseness of the circumambient Cold are condensed into thick Clouds, and fall down in Storms of Wind and Rain, first upon the Sea, from whence they rose, and then the attractive Power of the Mountain-cold, by a secret Magnetism between Vapour and Cold, attracts the waterish Vapours, intermixt with nitrous Particles, to the high Tops of Mountains and Hills, where they hang hovering in thick Fogs and waterish Mists, until the atmospherical Heat rarefies the nitrous Part of the Fog (which is always uppermost, and appears white and translucent) into brisk Gales of Wind, and the Intenseness of atmospherical Cold having attracted the Vapours into the colder Regions of the Air, where being condensed into Clouds, the Wind breaks, dissipates, and drives them before it, till they fall down in Rain, and water the Surface of the Earth. And this seems to be the Reason why, in Egypt, and those level Countries where they have no Mountains, they have little Wind and less Rain."
XVIII.