The History of the Royal Society of London/Chapter 8

by Robert Hooke

A

METHOD

For making a History of the Weather.

By Mr. HOOK.

 

FOR the better making a History of the Weather, I conceive it requisite to observe,

"1. ⁠The Strength and Quarter of the Winds, and to register the Changes as often as they happen; both which may be very conveniently shewn, by a small Addition to an ordinary Weather-cock.

"2. ⁠The Degrees of Heat and Cold in the Air; which will be best observed by a sealed Thermometer, graduated according to the Degrees of Expansion, which bear a known Proportion to the whole Bulk of Liquor, the beginning of which Gradation, should be that Dimension which the Liquor hath, when encompassed with Water, just beginning to freeze, and the Degrees of Expansion, either greater or less, should be set or marked above it, or below it.

"3. ⁠The Degrees of Dryness and Moisture in the Air; which may be most conveniently observed by a Hygroscope, made with the single Beard of a wild Oat perfectly ripe, set upright and headed with an Index, after the Way described by Emanuel Magnan; the Conversions and Degrees of which may be measured by Divisions made on the rim of a Circle, in the Center of which, the Index is turned round: The Beginning or Standard of which Degree of Rotation, should be that, to which the Index points, when the Beard, being throughly wet, or covered with Water, is quite unwreathed, and becomes strait. But because of the Smalness of this Part of of the Oat, the Cod of a wild Vetch may be used instead of it, which will be a much larger Index, and will be altogether as sensible of the Changes of the Air.

"4.⁠The Degrees of Pressure in the Air; which may be several Ways observed, but best of all with an Instrument with Quick-silver, contrived so, as either by means of Water, or an Index, it may sensibly exhibit the minute Variations of that Action.

"5.⁠The Constitution and Face of the Sky or Heavens; and this is best done by the Eye; here should be observed, whether the Sky be clear or clouded; and if clouded, after what Manner; whether with high Exhalations or great white Clouds, or dark thick ones. Whether those Clouds afford Fogs or Mists or Sleet, or Rain, or Snow, &c. Whether the under side of those Clouds be flat or waved and irregular, as I have often seen before Thunder, Which way they drive, whether all one Way, or some one way, some another, and whether any of these be the same with the Wind that Blows below; the Colour and Face of the Sky at the rising and setting of the Sun and Moon; what Haloes or Rings may happen to encompass those Luminaries, their Bigness, Form and Number.

"6.⁠What Effects are produc'd upon other Bodies: As what Aches and Distempers in the Bodies of Men; what Diseases are most rife, as Colds, Fevers, Agues, &c. What Putrefactions or other Changes are produced in other Bodies; as the sweating of Marble, the burning blue of a Candle, the blasting of Trees and Corn; the unusal Sprouting, Growth, or Decay of any Plants or Vegetables; the Putrefaction of Bodies not usual; the Plenty or Scarcity of Insects; of several Fruits, Grains, Flowers, Roots, Cattel, Fishes, Birds, any thing notable of that Kind. What Conveniences or Inconveniences may happen in the Year, in any kind, as by Floods, Droughts, violent Showers, &c. What Nights produce Dews and Hoar-Frosts, and what not?

"7.⁠What Thunders and Lightnings happen, and what Effects they produce; as souring Beer or Ale, turning Milk, killing Silkworms, &c?

"Any thing extraordinary in the Tides; as double Tides, later or earlier, greater or less Tides than ordinary, rising or drying of Springs, Comets or unusual Apparitions, new Stars, Ignes fatui or shining Exhalations, or the like.

"These should all or most of them be diligently observed and registred by some one, that is always conversant in or near the same Place.

"Now that these, and some others, hereafter to be mentioned, may be registred so as to be most convenient for the making of Comparisons, requisite for the raising Axioms, whereby the Cause or Laws of Weather may be found out; it will be desireable to order them so, that the Scheme of a whole Month may at one View be presented to the Eye: And this may conveniently be done on the Pages of a Book in Folio, allowing fifteen Days for one side, and fifteen for the other. Let each of those Pages be divided into nine Columns, and distinguished by perpendicular Lines; let each of the first six Columns be half an Inch wide, and the three last equally share the remaining of the Side.

"Let each Column have the Title of what it is to contain, in the first at least, written at the Top of it: As, let the first Column towards the left hand, contain the Days of the Month, or Place of the Sun, and the remarkable Hours of each Day. The second, the Place, Latitude, Distance, Ages and Faces of the Moon. The third, the Quarters and Strength of Winds. The fourth, the Heat and Cold of the Season. The fifth, the Dryness and Moisture of it. The sixth, the Degrees of Pressure. The seventh, the Faces and Appearances of the Sky. The eighth, the Effects of the Weather upon other Bodies, Thunders, Lightnings, or any thing extraordinary. The ninth, general Deductions, Corollaries or Syllogisms, arising from the comparing the several Phaenomena together.

"That the Columns may be large enough to contain what they are designed for, it will be necessary, that the Particulars be expressed with some Characters, as brief and compendious as is possible. The two first by the Figures and Characters of the Signs commonly used in Almanacks. The Winds may be exprest by the Letters, by which they are exprest in small Sea-Cards; and the Degrees of Strength, by 1, 2, 3, 4, &c. according as they are marked in the Contrivance in the Weather-cock. The Degrees of Heat and Cold may be exprest by the Numbers appropriate to the Divisions of the Thermometer. The Dryness and Moisture, by the Divisions in the Rim of the Hydroscope. The Pressure by Figures, denoting the Height of the Mercurial Cylinder. But for the Faces of the Sky, they are so many, that many of them want proper Names; and therefore it will be convenient to agree upon some determinate ones, by which the most usual may be in brief exprest. As let Clear signify a very clear Sky without any Clouds or Exhalations: Checquer'd a clear Sky, with many great white round Clouds, such as are very usual in Summer. Hazy, a Sky that looks whitish, by Reason of the Thickness of the higher Parts of the Air, by some Exhalations not formed into Clouds. Thick, a Sky more whiten'd by a greater Company of Vapours: these do usually make the Luminaries look bearded or hairy, and are oftentimes the Cause of the Appearance of Rings and Haloes about the Sun as well as the Moon. Overcast, when the Vapours so whiten and thicken the Air, that the Sun cannot break through; and of this there are very many Degrees, which may be exprest by a little, much, more, very much overcast &c. Let Hairy signify a Sky that hath many small, thin, and high Exhalations, which resemble Locks of Hair, or Flakes of Hemp or Flax; whose Varieties may be exprest by strait or curv'd, &c. according to the Resemblance they bear. Let Water'd signify a Sky that has many high thin and small Clouds, looking almost like water'd Tabby, call'd in some Places a Mackrel Sky. Let a Sky be call'd Wav'd, when those Clouds appear much bigger and lower, but much after the same manner. Cloudy, when the Sky has many thick dark Clouds. Lowring, when the Sky is not very much overcast, but hath also underneath many thick dark Clouds which threaten Rain. The Signification of gloomy, foggy, misty, sleeting, driving, rainy, snowy, Reaches or Racks Variable, &c. are well known, they being very commonly used. There may be also several Faces of the Sky compounded of two or more of these, which may be intelligibly enough exprest by two or more of these Names. It is likewise desirable, that the Particulars of the eighth and ninth Columns may be entred in as little Room and as few Words as are sufficient to signify them intelligibly and plainly.

"It were to be wisht that there were diverse in several Parts of the World, but especially in distant Parts of this Kingdom, that would undertake this Work, and that such would agree upon a common Way somewhat after this Manner, that as near as could be, the same Method and Words might be made Use of. The Benefit of which Way is easily enough conceivable.

"As for the Method of using and digesting those so collected Observations; that will be more advantageously considered when the Supellex is provided; a Workman being then best able to fit and prepare his Tools for his Work, when he sees what Materials he has to work upon.

A

SCHEME,

AT ONE

View representing to the Eye the Observations of the Weather for a Month.

Days of the Month and Place of the Sun.	Remarkable Houses.	Age and Sign of the Moon at Noon.	The Quarters of the Wind and its Strength.		The Degree of Heat and Cold.	The Degree of Dryness and Moisture.		The Degree of Pressure.	The Faces or visible Appearances of the Sky.	The notablest Effects.	General Deductions to be made after the Side is fitted with Observations: As,
	4		W.	2	93/8⁠	2	5	291/10⁠	Clear Blue, but Yellowish in the N. E clouded toward the S. checker'd Blue.	A great Dew Thunder, far to the South. A very great Tide.	From the last Q. of the Moon to the Change the Weather was very temperate, but cold for the Season; the Wind pretty constant between N. & W. A little before the last great Wind, and till the Wind rose at its highest the Quick-silver continued descending till if came very low; after which it began to reascend, &c.
	8	27		3	121/2
14	12	♉ 9.46	|	31/3	16	2	8
♊								291/2
	4
12.46	8	Perigeu.			101/8	2	9
	12		W.SW	1	71/2			23/2
	8		N.W.	3	9	28	1/2	291/10	A clear Sky all Day, but little checker'd at 4. P. M. it Sun-set red and hazy.	Not by much so big a Tide as Yesterday. Thunder in the North.
15				4
♊	4	28	N.	2	81/2	2	9
13.40	5	♉ 24.5		1
	10				7	2	10	29
	10	N Moon at 7. 25 A.M.	S.	1	10	10		281/2	Overcast and very lowering.	No Dew upon the Ground, but very, much upon Marble-stones &c.
16
♊
14.37		♊ 10.8
		&c.	&c.		&c.	&c.		&c.

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