A Scheme of a Diary of the Weather; Together with Draughts and Descriptions of Machines Subservient Thereunto; Inscribed to the President and Fellows of the Royal Society; By Roger Pickering, F. R. S. and V. D. M.

I. A Scheme of a DIARY of the Weather; together with Draughts and Descriptions of Machines subservient thereunto; inscribed to the President and Fellows of the Royal Society; by Roger Pickering, F. R. S. and V. D. M. The Introduction. Read at a Meeting of the Royal Society, May 3, 1741. THE Usefulness and Importance of Meteorological Tables, or Diaries of the Weather, are too well known to this learned Society, to need mentioning with any other View, than as an Excuse under which the Author of the following Observations would shelter himself, for presuming to engage in a Subject, upon which so many, infinitely his Superiors, have written: For, when both the Health and Trade of Mankind considerably depend upon the different States of the Atmosphere, the meanest Endeavours to contribute to a Knowledge of it may not be without their Use, and are, at least, excusable. A Sense of the Importance of observing the Weather induced Hippocrates, in his Remarks upon the Epidemic Diseases in Thasos, to premise a general History of the Weather preceding them; and with the same View did our great Mr. Boyle turn his Thoughts so closely upon the same Subject: whose Example, being followed by several judicious Inquirers into Nature, both abroad and at home, has brought the Natural History of the Air to a surprising Degree of Perfection, beyond what the Antients ever could could pretend to, or even thought of. Had but each County in England Gentlemen of such Sentiments, who would charge themselves with the annual Trouble of sending a regular Account of the Weather to this learned Body, by it to be compared and digested, to what Degrees of Accuracy may we not suppose a Knowledge of the Nature and Affections of the Atmosphere may be brought; and how well may we not hope to be guarded against the Disorders, which, as Islanders, we are exposed to, by such a close Inquiry into the Nature of that necessary Fluid in which we breathe! Not to mention the Advantages which several important Branches of Trade may receive from such Measures: And were the digested Observations of the Royal Society compared with those of foreign Societies, formed upon the same Plan, how short a Time would bring this Part of Philosophy to the greatest Degree of demonstrable Certainty! The Trouble of making and keeping such Meteorological Registers, which, in all Probability, prevents several Gentlemen from performing this Piece of Service to the Public, might be rendered very inconsiderable, by the Proposal of an easy, as well as comprehensive, Method for a Diary, and a Set of simple and convenient Machines for making the necessary Observations. The Plan of the Ephemerides Ultra-jectinae, tho' comprehensive, is, with Submission, very perplex'd; and the several others, mention'd in the Philosophical Transactions, perhaps, do not include all the Particulars of which such a Diary should consist. The Society of Edinburgh has prefaced to their Medical Essays a Scheme (which I had not the Pleasure of seeing seeing till a great while after I had fallen into the following Method) the most calculated for Usefulness; but their Machines are neither so simple nor accurate, as such a Work requires; not to mention their being entirely without one for observing the Force of the Wind. After these free Expressions, nothing but a sincere Intention would justify me to myself, for presuming to offer the following Plan; except it were a full Dependence upon the Honour and Candour of the Royal Society, whose Humanity and Condescension to the meanest of its Well-wishers I have more than once already experienced. S E C T. I. An Account of the Diary in general. On a Page of a Folio Paper-Book, opening broadways, are drawn, at proper Distances, nine horizontal, and seven perpendicular Lines; in the void square Spaces of which the Particulars of the Diary are written down. The first of the horizontal Lines is for the Days of the Month and Week, on which the Examination is made: The second for the Hour of the Day: The third for the Weight of the Air: The fourth for its Heat: The fifth for its Moisture, or Dryness: The sixth for the Quarter of the Wind: The seventh for its Force: The eighth for the Weather; as whether it be rainy, or cloudy, or clear: The ninth for the Quantity of Rain; and the Space between between the last Line and the End of the Paper, for the Bill of Mortality. The seven perpendicular Lines are for the seven Days of the Week; which, in our Diary, begins with the first Day, according to the Jewish Account, by us called the Sabbath, or Sunday. If you therefore carry your Eye along the Paper from Left to Right, you may, at one View, see the Weight of the Air, and the Degrees of Heat and Moisture, &c. for the whole Week. If you carry your Eye from Top to Bottom down the Column, for any one Day, you see regularly the Whole of the Observations in one Line for that Day. Four Pages, or Weeks, we allow to each Month, and then leave a void Page for the Observations made in that Month; and the overplus calendar Days are carried on to the Page allotted for the next Month; only taking care to describe in every such Page, where the Ending and Beginning of two different Months are to be found, the Names of both the Months, directly over their final and initial Day. The Abstract of the weekly Bill of Mortality is apparently a Part of Observation peculiar to this Plan, under which Article all acute Cases, depending on the State of the Air, are set down. Perhaps the Ignorance of the Searchers, appointed to inspect dead Bodies, as to the precise Diseases People die of, may lay this Method open to Objection: To which it may be sufficient to answer, That this being obviously a requisite Article for a Diary, we must be content to take our Advices on this Point from such Hands, rather than none; especially, as all Political Arith- Arithmetic has always been allowed upon no more certain a Foundation. Sect. II. A View of the Machines in general. The Machines necessary to the making Observations for a Diary of the Weather, are these five: 1. The Barometer. I have found those with open Cisterns more sensible than the portable ones. That with which I make my Observations, is with an open Cistern, furnish'd with a Micrometer, that divides an Inch into 400 Parts; by which I am capable of perceiving the most minute Alteration of the Gravity of the Air: It was made by Mr. Bird of the Strand; whose Accuracy in Graduation deserves, I think, Notice and Encouragement. 2. The Thermometer. Mine is one made by Fahrenheit's Scale on one Side, with its Correspondence to the Graduation of the Alcohol Thermometer on the other. Of the three next Machines, two are new, and the other considerably altered, and, I hope, improved, from one offered to the Society a great while ago. Note, All the Machines, except the Barometer, are exposed to the open Air. The Thermometer and Hygrometer are placed in a little Shed, made for their Reception, against my Study-Window, where I can see the Graduation thro' the Glass; and, by lifting up the Sash, can take them in, as Occasion requires. I HAD, for some time, made use of Dr. Hooke's Hygrometer, made of the Beard of a wild Oat, let in a small Box, with a Dial-plate and an Index; but I soon found an Inconvenience, without the remedying of which no Dependence could be had on this Machine; viz. its making more than one Revolution in a Night. I endeavoured to remedy this by the following Method, described in Tab I. Fig. 6. At the vertical Point, from which Moisture and Dryness are graduated, I caused a small Circle to be described; the lower Arch of which should just intersect with that Arch, round which the Index of the Oat described its Circuit. In the Centre of this small Circle I placed a Pin, easily turning in the central Cavity, and furnish'd with a flat Piece of thin Ivory on its Head. This Piece of Ivory, intersecting with the Index of the Oat, by it was turned either to the moist or dry Side of its Graduation, as the Index made a double Revolution. I flatter'd myself with Success; but soon found, in the great Fogs we had last Winter, that the wild Oat is not a safe Material to make an accurate Hygrometer of: For, 1. In the great Fogs it grew limber; so as that the Weight of the Index brought it down upon the Plate, where its Friction prevented its further Motion. 2. It soon loses its Sensibility, grows harsh, and is absolutely unfit for Use. So I immediately turned my Thoughts upon some other for my Diary, and reserved this for my Study; where, or in any inclosed Place, it does well enough, and may be very useful in the following Respects; as, 1. To examine, in Cases of Sickness, the Dampness of Rooms. 2. To examine Damps in subterraneous Cavities, being let down with a Weight, where a Light would sometimes set the Place on Fire. 3. To observe the proper State of Dryness in Warehouses, Wine-vaults, Studies, where Damps would be detrimental and pernicious. 4. To examine the Strength of sudden Fogs, and the comparative Dampness of particular Situations. As a Succedaneum to this, I thought upon a statical one; it recurring to my Mind, That the Weight and Moisture of the Air being but two Properties of one and the same Body, a statical Hygrometer (ceteris paribus) promised the best Assistance towards a more complete Knowledge of the Barometer, which acts upon statical Principles; and that these two Machines must have a reciprocal Correspondence with each other. I then remember'd, that the great Mr. Boyle had mentioned something of this Nature; after consulting whom, I made the following Machine, acting upon his Principles, but formed in a Manner differing from his. I caused a Balance to be made to turn with half a Grain, ordering that the Axis of the Balance should, on one Side, be drawn out to the Length of one Inch, and its End to be furnished with a Male Screw, to which a light Index with a Female Screw might be fixed. I had this Balance fastened in a Wainscot Box, twelve Inches in Length, nine in Diameter, and four in Depth at Top, but gradually widening towards the Bottom, with a Back to slide up and down in a Groove. The Axis, already mentioned, of an Inch Length, came through a Hole in the Front of the Box, and then had the Index fastened on, which described the Segment of a Circle upon a brass Plate, silver'd and graduated into 180 Gr. as if it had consisted of a perfect Semicircle, or two Quadrants. The Reason why the Graduation did not begin exactly with the diametrical Line was, to prevent the Friction of the Brachia of the Balance, with the little Drop placed at the Bottom of the Axis already mentioned. My next Concern was to charge this Balance. The Beam turned, as has been said, with half a Grain; and every such Turn, after repeated Trials, moved the Index somewhat more than one Degree of the 180 described upon the Plate; so I immediately pitched upon a Four Peny-weight all but six Grains, which contained as many half Grains as there were Degrees. This Weight I fixed with a Thread to one Brachium of the Balance, without any Scale, the several Threads or Silk Strings of which, as they would imbibe more Moisture, would make the Machine less accurate; and the other Brachium I charged with a Sponge, suspended likewise by a Thread, of such a Weight, when reduced to absolute Dryness, as made an Equilibrium; and then screwing on the Index to the first Degree of the 180, and exposing the Machine, thus ordered, to the open Air, in one Night's time the Index had got to the 70th Degree; which, as the Sponge had been absolutely dry, must have been the true State of the Air, as to Moisture, at that time. I find I find this Machine extremely sensible and accurate; it will alter 10 Degrees in a Night, and as many in a Day; and has, I think, the following Advantages: 1. It is more portable than any, except that of the wild Oat; and, upon any Accident, more easily and speedily rectified than it, or any other whatever. 2. Being graduated from absolute Dryness, it is best calculated for the Discovery of the true State of the Air, as to Moisture. 3. The near Correspondence between the Degrees on the graduated Plate, and the Weight of the Moisture necessary to be imbibed or exhaled, to make either Brachium of the Balance preponderate every such Degree, gives it the Preference to any other. For a more perfect Idea of this Machine, see Tab. I. Fig. 1. where it is viewed on the Inside, the Back being slid up. At Fig 2. is represented the Plate with its Graduations and Index, as it should appear on the Front of the Case. Sect. IV. Of the Anemoscope. The Anemoscope is a Machine four Feet and a Quarter high, consisting of a broad and weighty Pedestal, a Pillar fastened into it, and an iron Axis, of about half an Inch Diameter, fastened into the Pillar. Upon this Axis turns a wooden Tube, at the Top of which is placed a Vane, of the same Materials, 21 Inches long, consisting of a Quadrant, graduated and shod with an iron Rim, notched to each Degree; and a Counterpoise, of Wood as in the Figure, on the other. Through the Centre of the Quadrant runs an iron Pin, upon which are fastened two small round Pieces of Wood, which serve as moveable Radii to describe the Degrees upon the Quadrant, and as Handles to a Velum or Sail, whose Plane is one Foot square, made of Canvas stretched upon four Battens, and painted. On the upper Batten, next to the fhod Rim of the Quadrant, is a small Spring, which catches at every Notch corresponding to each Degree, as the Wind fhall, by pressing against the Sail, raise it up; and prevents the falling back of the Sail, upon the lessening of the Force of the Wind. At the Bottom of the wooden Tube is an iron Index, which moves round a circular Piece of Wood fastened to the Top of the Pillar on the Pedestal, on which are described the thirty-two Points of the Compass. The Figure of this Machine may be seen Tab. I. Fig. 3. Its Uses are the following: 1. Having a circular Motion round the iron Axis and being furnish'd with a Vane at Top, and Index at the Bottom, when once you have fixed the artificial Cardinal Points, described on the round Piece of Wood on the Pillar, to the same Quarters of the Heavens, it gives a faithful Account of that Quarter from which the Wind blows. 2. By having a Velum or Sail elevated by the Wind along the Arch of the Quadrant, to an Height proportionable to the Power of the Column of Wind pressing against it, the relative Force of the Wind, and its comparative Power, at any two Times of Examination, may accurately be taken. 3. By having a Spring fitted to the Notches of the Iron with which the Quadrant is fhod, the Velum is pre- prevented from returning back upon the Fail of the Wind; and the Machine gives the Force of the highest Blast, since the last Time of Examination, without the Trouble of watching it. I have carefully examined the Dependence that may be had upon this Machine, during the late Storms in February 1743, by comparing the Height to which the Wind then forced the Velum, with the Deal Letter. The 19th of Feb. Sabbath, 8 a.m. the Anemoscope was at 75: The Deal Letter for that Day called it a Storm. The Saturday following, being the 25th, at 8 p.m. the Machine was at 79: The Deal Letter called that a violent Storm. The Wednesday following, the last of Feb. it was at 84: The Deal Letter called that a violent Storm. So that it appears, that, in such as the Sailors allow to be violent Storms, the Machine has hitherto answered well, and has had six Degrees to spare for a more violent Gust, before it comes to an horizontal Position. It is certainly to be depended upon in ordinary Weather, the Velum being hung so tender, as to feel the gentlest Breeze. But, after all, I must freely own, that I fear the exposing this Machine to all Winds, for a Continuance, must soon disorder it; and that irregular Blasts and Squalls cannot fail in a short time to impair it. It may not therefore be amiss, to prevent this, for Gentlemen to take the Machine in violent Weather; and, by taking the Tube off the iron Axis, to make their Observations with the Tube, Vane, and Velum, in their Hands; which, as it is very light, and far from cumbersome, is easy to do, as I have often experienced. Sect. V. Of the Ombrometer. This Machine consists of a tin Funnel, whose Surface is an Inch square, a flat Board, and a glass Tube let into the Middle of it in a Groove (the Length and Breadth of both Board and Tube being ad Libitum), and an Index. My Board is about three Feet long, to answer the Height of the Rails that go round the Top of my House, to one of which it is hung, clear of any Obstacle to prevent the free Fall of the Rain, with four little Staples that slide over as many Tenter-hooks. The Bore of my Tube is about half an Inch; which, at a Medium, is the best Size, a larger Bore obliging you to make your Graduation the more contracted, and, consequently, the less plain and accurate; and a lesser not permitting you to return the Water out of the Tube when full, without the Adhesion of a great deal to its Sides; which, when you have placed the Tube in its perpendicular Situation, subsides, and sometimes fills up $\frac{3}{2}$ of an Inch; which, without Care, must necessarily make great Mistakes in the Diary. The Method of graduating the Board is this: I had a Vessel of Tin made, whose Contents were exactly a Cubic Inch. With this Vessel, filled with Water exactly to its Surface, I frequently gauged the Tube, till, by repeated Trials, I had found the Height to which a Cubic Inch of Water would rise in it. The Space answering to this on the Board I had graduated into 32 equal Parts, and took the same Method with the rest of the Tube, till in the same man- ner I had graduated four such Inches. Now the Surface of the Funnel being, as has been said, exactly a square Inch, no Rain can by it get into the Tube, but such as falls within the Square of one Inch; which, as the Shower is more or less, has its exact Quantity shewn upon the Board, on which a moveable Index is placed. This Machine has highly answered my Expectation; its Form being very simple, and easily repaired, if any Accident happen. For, should the Tube be broke, 'tis only rubbing out the Graduation, which is marked with a Black-lead Pencil upon the Board painted white, and gauging your new Tube with the Cubic Measure for a new Graduation, and your Machine is again complete. I had one Tube broke, and about three Hours Pains set all to-rights. In Winter it will be necessary to let no Depth of Water remain in the Tube; for, should there be a Frost, the Expansion of the Ice will certainly break it. The Machine will equally serve for dissolved Hail and Snow. Its Figure may be seen Tab. I. Fig. 5. Sect. VI. Of the Monthly Observations. The vacant Page at the End of every four Weeks, reserved for Observations occurring in the preceding Month, and giving a summary Account of the greatest Difference of the Weather in it, is a Method peculiar to this Diary; and one which, I flatter myself, will be allowed exceeding pertinent and useful. The great End of this, and all Diaries, is to furnish Materials for a Set of sound Observa- tions, upon which to build a thorough Knowledge of the Atmosphere, and its Effects upon Mankind: And it is easy to see what great Advantage to this Part of Natural Knowledge must arise from a Variety of Observations, made by different Men of Application and Judgment, upon one and the same Subject. Besides, in this Portion of our Design may be included, what could not well without Perplexity be thrown into the Columns of the Diary, all the Meteorological Appcarances of the Aurora Borealis, Lightning, Thunder, &c. together with Abstracts of the most authentic Accounts of such Phenomena, as at any time in the preceding Month have been seen in different Parts of our own Country, or abroad. But this Article must be left to every Gentleman's Judgment; it opening a fair Field for the most happy Advancements of many Parts of Natural Knowledge. An Explanation of the Characters in the Diary. This — Line implies the Machine's being at the same Degree as it was in the preceding Observation. This O Character in the Spaces for the Force of the Wind implies a Calm. Note, 1st, None, but the cardinal and subcardinal Points of the Compass are commonly marked, unless in case of a Storm. 2dly, In the Abstract of the Bill of Mortality, which comes out on a Tuesday, the Account in each Week is to be compared from the Tuesday of the Week before, to the Tuesday in that Week where the Abstract is placed. April | Days of the Month | 1 Sabbath | 2 Monday | 3 Tuesday | 4 Wednesday | 5 Thursday | 6 Friday | 7 Saturday | |------------------|-----------|----------|-----------|-------------|------------|----------|------------| | Hours of the Day | 8 a.m. | 8 p.m. | 8 a.m. | 8 p.m. | 8 a.m. | 8 p.m. | 8 a.m. | | Barometer | 29 400 | 29 400 | 29 400 | 29 400 | 29 400 | 29 400 | 29 400 | | Thermometer | 37 | 36 | 37 | 35 | 35 | 40 | 45 | | Hygrometer | 70 | 77 | 79 | 80 | 74 | 77 | 74 | | Anemoscope | Quarter. W.| N. W. | | | S. E. | N. W. | W. | | Force | 28 | 30 | 74 | 16 | 20 | 16 | 0 | | Weather | Sleet. | Rains | Snow. | Sleet. | Starlight. | Rain. | Cloudy. | | Ombrometer | 13 | 13 | 22 | 3 | 1 | 13 | | | Bill of Mortality| Buried. | Males - 176 | Females - 217 | Total - 393 | Died of Apoplexy - 1 | Fever - 52 | Small Pox - 22 | | | | | | | Asthma - 8 | Gripes - 4 | Suddenly - 2 | | | | | | | Colic - 1 | Lunatic - 2 | | OBSERVATIONS in APRIL 1744. | Days of the Month | Days of the Week | Hours of the Day | |------------------|-----------------|-----------------| | 19 | Mond. | M. | | | | 12 | | 20 | Friday. | P. M. | | | | 8 | | 24 | Tuesd. | P. M. | | | | 10½ | LAST Night, at 8° Hour, carefully watched, whether the lunar Eclipse had any Effect upon the Hygrometer; but could not, after several Examinations, perceive that it had any. This is the first Day of our being favoured with warm Spring Weather. The Thermometer at 8 this Morning was at 65. It now lightens towards the S. E. This is the first we have had this Year. A SUMMARY of the greatest Difference of the WEATHER in April 1744. | Days of the Month | Days of the Week | Hours of the Day | |------------------|-----------------|-----------------| | 21 | Satur. | A. M. | | | | 3 | | | | P. M. | | | | 11 | | 5 | Thurs. | P. M. | | | | 8 | | 21 | Satur. | P. M. | | | | 8 | | 6 | Friday. | A. M. | | | | 8 | | 3 | Tuesd. | A. M. | | | | 8 | | 21 | Satur. | P. M. | | | | 8 | | 3 | Tuesd. | A. M. | | | | 8 | Mercury Highest being then 30° 5′ 3″ Lowest - - - - - 29° 1′ 16″ Hottest - - - - - 75 Coldest - - - - - 34 Moistest - - - - - 81 Driest - - - - - 65 Quarterly most from S. E. Anemoscope Force greatest from N.W. 74 Weather very unconstant. Ombrometer Most Rain on 7th in the Night 24 Total Rain 5 Inch and 5′ 6″ Greatest in the 3d Week 432 Least 1st Week - 393 Total - - - - - 1702 A Description of the Figures in TAB. I. Fig. 1. aaaa. The Hygrometer seen in the Inside. bb. The Balance. c. A small Piece of Wood, by which the Balance is fastened to the Box. d. The Sponge. e. The Weight. ff. Two little Rings, by which the Hygrometer is hung up. Fig. 2. The graduated Plate on the Front of the Machine, with its Index and Divisions. Fig. 3. The Anemoscope. a. The Pedestal. b. The Pillar, in which the iron Axis is fitted. c. The Circle of Wood, on which are described the 32 Points of the Compass. d. The Index. e. The wooden Tube upon its Axis. f. The Velum. g. The graduated Quadrant. h. The Counterpoise of the Vane. Fig. 4. The Velum taken off. a. The Plane of the Velum. b. The Spring. cc. The wooden Radii. dd. The Holes, thro' which the Pin, in the Centre of the Quadrant, goes. Fig. 5. The Ombrometer. aa. The Board. bb. The Tube. c. The Graduation. d. The Funnel fixed in the Tube. e. The Funnel one Inch square. Fig. 6. The Wild-Oat Hygrometer. a. The Box and Plate. b. The wild Oat, with the Index upon it. c. The Pin, with a small Piece of Ivory on its Head. II. A Letter from Mr. William Watson, Apothecary, F. R. S. to the Society, concerning some Persons being poisoned by eating boiled Hemlock. Gentlemen, Read May 10, 1744. Notwithstanding the Number of Instances, which occur among Writers, concerning the poisonous Quality of our common Hemlock, or *Cicuta major* of Caspar Bauhin; such as, that of Cardanus mentioning a Man kill'd by a Cake, wherein this Plant was an Ingredient; that of Brassavola, who assures us, that it is mortal not to Men only, but to Geese and Swine; as well as those