The Shepherd of Banbury's Rules to Judge of the Changes of the Weather, Grounded on Forty Years' Experience Part 2

XII.

WINDS. _Observe, that in eight Years' Time there is as much South West Wind, as North East, and consequently as many wet Years as dry._

THIS must be allowed a very extraordinary Aphorism from a Country Shepherd, but at the same Time it is very agreeable to the Observations of Dr. _Hooke_, Dr. _Derham_, Dr. _Grew_, and other able Naturalists, who with unwearied Pains and Diligence have calculated the Quant.i.ty of Rain falling in one Year, and compared it with what fell in another.

Lord _Bacon_, that Honour to our Nation and the Age which produced him, informs us, that it was an old Opinion there was a total Revolution of the Weather once in forty Years, and wishes it was inquired into. I cannot tell whether this has ever been done or not, but I think there is good Reason to conclude that there is a natural Balance established of wet and dry Weather, as of Light and Darkness, Heat and Cold, and other such like Variations.

IT may not be amiss to caution the Reader against a Mistake into which the Manner of this Rule being stated may easily lead him. It is this, that South West Winds cause Rain, and North East Winds fair Weather, which however is not a Thing clear or certain by any means. This indeed is true, that South West Winds and Rain, North East Winds and fair Weather come together, generally speaking. But the Question is, which causes the other, and a more difficult Question cannot easily be stated, because there seems to be Facts on both sides. South West Winds seldom continue long without Rain, this seems to prove the affirmative, but on the other Hand, when in hard Weather, Rain begins to fall, the Wind commonly veers to the South West, this looks as if the Rain caused the Wind.

BUT to keep close to the Shepherd's Observation. There is one Thing seems strongly to confirm it, which is this, that in any given Place the Quant.i.ty of Rain one Year with another is found to be the same by Experience, according to which the following Table has been calculated, for the mean Quant.i.ty of Rain falling one Year with another in those Places that are mentioned, and on this Proportion the other seems to be founded.

At Harlem 24 Inches Delf 27 Dort 40 Middleburg 33 Paris 20 Lyons 37 Rome 20 Padua 37-1/2 Pisa 34-1/4 Ulm 27 Berlin 19-1/2 In Lancas.h.i.+re 40 Ess.e.x 19-1/2

XIII.

_When the Wind turns to North East, and it continues two Days without Rain, and does not turn South the third Day, nor Rain the third Day, it is likely to continue North East for eight or nine Days_, all fair; _and then to come to the South again_.

IN my Opinion this and the subsequent Remarks depend entirely upon Observations, and may serve rather to found an Hypothesis, than seem be deduced from one. That the Variations of the Wind depend on certain Causes, and may consequently be reduced to Rules, is highly probable, and such Observations as these render it in a manner certain. But to explore these Causes, and to explain them in such a manner as to account for these Phaenomena in a satisfactory manner, requires not only great Sagacity but much Experience, and many Years' Observation, which, however, considering the great Benefits that would result to Mankind from establis.h.i.+ng such a THEORY, would be Time well bestowed.

WE may however easily conceive that a constant North East Wind must be accompanied with fair Weather. For whatever the causes of Winds may be, yet on this side the Equator, a strong and settled North East always buoys up the Clouds and keeps them suspended. This has been long observed by, and pa.s.ses for a settled point amongst Seamen. The Reason of it however cannot be so easily a.s.signed, at least a satisfactory Reason, for as to Suppositions, every fanciful Man can furnish them at Pleasure.

THIS, as well as the following Observations, very plainly and clearly prove, that in this Part of the World fair Weather attends one Wind, and wet another, but which is the Cause and which the Effect, or whether both are not the Effects of some other Cause, I pretend not absolutely to determine. But inasmuch as it is certainly known, that Rains attend in other Climates those Winds that are here attended with fair Weather, it seems more agreeable to suppose that rainy Weather is occasioned chiefly by West Winds, because loaded with moist Vapours from the Sea.

XIV.

_If it turn out again out of the South to the North East with Rain, and continues in the North East two Days without Rain, and neither turns South nor rains the third Day_, it is like to continue North East for two or three months.

_The Wind will finish these Turns in three Weeks._

THIS Observation is of the same nature with the former, and is plainly deduced from long experience. Our Author seems to contradict himself in saying that these Winds finish their Turns in three Weeks, but his true Meaning certainly is, that they are about three Weeks in turning from the South to the North East again. Some very great men have laid it down as a thing certain, that the Variations of the Wind are to be accounted for by the Alteration of the Balance of the Air, occasioned by the different Effects of Heat and Cold; but other Writers again insist very copiously on the Effects which Winds have upon the Air, and thus confound us in a Circle of Causes and Effects, whence it is plain that they do not thoroughly understand the Subject themselves, and therefore it is no Wonder that they are not able to explain it to others.

IN some Parts of the World, and especially between the Tropicks, the Winds are regular, and therefore our Philosophers seem to talk more rationally about them. But in our Northern Countries the Alterations of the Wind are so frequent, sudden, and often so little agreeable to the Season, that such general Reasonings will by no Means serve to explain them. It is however very reasonable to suppose that the same general Cause prevails here as between the Tropics, but with less Certainty, because the Power of the Sun is not so great, and the Determinations of the Winds depend on the Situation of Mountains, Rocks, and Woods, which direct the Air driving against them into certain Courses, so that it is impossible to explain, or indeed to judge of the Course of the Winds till the Country is thoroughly known, and all those Eminences that can affect the Winds are well considered.

FROM these Reflections the Value of our Shepherd's Observations will clearly appear. He was not Philosopher enough to talk in this Style, but by a long and steady Attention he came to know, experimentally, what perhaps few Philosophers, with all their Sagacity, would have been able to have found out.

XV.

S. W. WINDS. _After a northerly Wind for the most Part two months or more, and then coming South, there are usually_ three or four fair Days at first, and then, on the fourth or fifth Day, comes Rain, _or else the Wind turns North again_, and continues dry.

THIS is likewise a very judicious and very useful Observation, and yet it is not a difficult matter to account for it. It is a common Observation, and a very true one, that there is usually fair Weather before a settled course of Rain. The Winds that bring the dark rainy Clouds that obscure the Sky, and cause dull cloudy Weather, often raise these Vapours to such a height, that they are attracted into the cold Region above our Sight, till being condensed there, they fall down upon us again in Snow or Rain, according to our Author's Observation.

BUT if, after a seeming Tendency to Rain, there follow several Days of fine Weather, it is a certain Indication that the Temper of the Air is altered, and that these Vapours had been driven off before they had time to condense, which is confirmed by the Change of the Wind on such Occasions.

ALL these Observations are to be understood in a proper Lat.i.tude, and not strictly and according to the very Letter. For Rain may fall the sixth or seventh Day, or the Wind may change the second or third.

Besides, a Man who would make use of these Observations in the Country, must consider attentively the Situation of the Place where he lives, the bearing of the Sea, Marshes, Ponds, Lakes, Woods, Mountains, Rocks, _&c._ For without making proper Allowances for these, all such Observations on the Weather will be apt to fail him.

XVI.

_If it return to the South within a Day or two without Rain, and turn Northward with Rain, and return to the South, in one or two Days, as before, two or three Times together after this Sort_, then it is like to be in the South, or South West, two or three Months together, _as it was in the North before_.

_The Winds will finish these Turns in a Fortnight._

THIS may appear a little perplexed to an ordinary Reader, but a little Attention will make it very clear and plain; and whoever considers what mighty Uses may be made of the Foresight of Weather for a Month or two, will not think this Labour ill bestowed. I must confess I look upon these three Rules in Relation to the Wind as the most useful in the whole Collection. Especially to Farmers and Country People, to whom they are of the greatest Consequence.

BUT it is a common Thing for such People to say, what Certainty is there that these Rules will prove true, what Probability is there that the Wind should continue so long in one Quarter, and then so long in another, how shall we be satisfied that there is any truth in this; or, if we cannot be satisfied as to the Truth of it, why should we depend upon any such like Observations?

TO this I answer, that they may have reasonable Satisfaction given them on this Head. Some of our great Naturalists, who had kept Journals of the Weather for many Years, have found that the same Wind blows every Year very near the same number of Days, and that there is a regular Continuance of different Winds annually in every Country. For Instance,

At _Utrecht_ they blow thus,

The N. Wind 42 Days.

The N. W. 33 The W. 77 The S. W. 58 The South 33 The S. E. 26 The E. 53 The N. E. 43 --- 365

IT is a Thing plain to every Capacity, that a Journal or Diary of the Winds may be kept any where, and if from such a Journal it appears that a given Wind blows for a certain Number of Days, then it follows, that if these can be determined with Certainty, the Time of their blowing may also be determined, at least with great Probability, which is as satisfactory an Answer as can be justly expected, because it shews that there is just and rational Ground for confiding in such Observations, when confirmed by long Experience.

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 Porp.u.s.s.es 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 s.h.i.+ning 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 s.h.i.+ning Meteors which fix upon the Masts and Sides of the s.h.i.+ps, and are only nitrous particles condensed by the circ.u.mambient Cold, and like that which the Chymists call Phosphorus, or artificial Glow-worm, s.h.i.+ne 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 circ.u.mambient 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.

CLOUDS. _In Summer or Harvest, when the Wind has been South two or three Days, and it grows very hot, and you see Clouds rise with great white Tops like Towers, as if one were upon the Top of another, and joined together with black on the nether Side_, there will be Thunder and Rain suddenly.

WE may very easily account for this Observation, because in Fact the Signs here mentioned are no other than Nature's apparatus for a Storm of Thunder and Lightning, which will be perfectly understood by attending a little to the Causes of these Meteors. Lightning is a great flame, very bright, extending every way to a great distance, suddenly darting upwards, there ending, so that it is only momentaneous. The Matter which produces the Fire, is the Oil of Plants, attenuated by the heat of the Day, and raised on high. Then whatever has exhaled from the Earth that is sulphureous or Oily, which is dispersed up and down in the Atmosphere, and is not continuous, is set on Fire by Turns, and the Flame dilates itself as far as the Tract of that Exhalation reaches.

Some other Substance pendant and floating in the Air meets with this also, with which it excites an effervescence, takes Fire and flashes along with it. Thunder is another bright Flame, rising on a sudden, moving with great Velocity through the Air, according to any Determination upwards from the Earth horizontally, obliquely, downwards in a right Line, or in several right Lines as it were in serpentine Tracts joined at various Angles, and commonly ending with a loud Noise or Rattling.

IT is observed that it thunders most when the Wind blows from the South, and least when it blows from the East. The great Principle of Thunder is Sulphur, as is evident from the Smell it leaves behind it; but in order to occasion such an Explosion, there must be other Ingredients mixed therewith, especially Nitre, of which the Air is always full, besides other Things, of which it is impossible to give any Account. The Tracts of this Sort of Matter fly about in the Air, and are as it were Lines of Gunpowder, and as in the firing of that Powder, the Fire begins at one End, and pursuing its Aliment proceeds to the other Extremity, and so the whole Ma.s.s of Powder is fired; we may from thence account for the Phaenomenon of Thunder. For in like Manner those inflamed Tracts which are suspended in the Air, flash from a Flame that runs from one Extreme to the other, wherever the Vein of Nourishment leads it. Hence those Rays of Thunder, which seem to be brandished through the Air, and sometimes to be split in two or more Tracts, and sometimes to return back, at other Times to be projected in Lines that are joined by various Angles, and this only because the Flame meets with Tracts lying in various Situations that cohere one with another. Therefore Thunder seems now to run horizontally, now from above downwards, now upwards from the Earth, for if the Matter of Thunder pressing out of the Earth is enflamed near the Ground, the Flame darting upwards, the Thunder will seem to be projected out of the Earth. If the same Tract be set on Fire at its upper end, the Flame will move downwards, and the Thunder will seem to descend out of the Sky.

HENCE we easily understand how it comes to thunder oftener in one Place than another, but most frequently in those where the Soil produces odoriferous Herbs, and abounds with Sulphur, and where the People are much exposed to the extreme Heat of the Sun. Thunder is less frequent in Places where there are few odoriferous Herbs, very little Sulphur, or where the Climate is watery and moist. For Instance, it thunders very much in _Italy_ and _Sicily_, and very rarely in _Egypt_, and the adjacent Countries. If it be demanded how it comes to thunder in the midst of the Ocean? The Answer is easy, because from the Bottom of the Ocean vast Tracts of sulphureous Matter are cast up through the Waters; as it happens to spring Waters in several Places, the Streams of which will take Fire from a lighted Candle. For sulphureous Exhalations bursting out together with the Waters, the fulmineous Matter in the Air is set on Fire when it meets with Exhalations or Vapours with which it can excite a vehement Effervescence. It is very clear from this Account, that the Clouds mentioned at the Top of the twenty-eighth Page are thunder Clouds, or Clouds big with the Materials of Thunder.