* * * * *

A way of preserving Ice and Snow by Chaffe.

The Ingenious Mr. William Ball did communicate the relation hereof, as he had received it from his Brother, now residing at Livorne, as follows;

The Snow, or Ice-houses are here commonly built on the side of a steep hill, being only a deep hole in the ground, by which meanes, they easily make a passage out from the bottom of it, to carry away all the water, which, if it should remain stagnating therein, would melt the Ice and Snow: but they thatch it with straw, in the shape of a Saucepan-cover, that the rain may not come at it. The sides (supposing it dry) they line not with any thing, as is done in St. Jeames's Park, by reason of the moistness of the ground. This Pit they fill {140} full of Snow or Ice (taking care that the Ice be made of the purest water, because they put it into their wine) over-spreading first the bottom very well with Chaffe; by which I mean not any part of the straw, but what remains upon the winnowing of the Corn; and I think, they here use Barley-chaffe. This done, they further, as they put in the Ice, or the Snow, (which latter they ram down,) line it thick by the sides with such Chaffe, and afterwards cover it well with the same; and in half a years lying so, 'tis found not to want above an eight part of what it weighed, when first put in. When ever they take it out into the Aire, they wrap it in this Chaffe, and it keeps to admiration. The use of it in England would not be so much for cooling of drinks, as 'tis here generally used; but for cooling of fruits, sweetmeats &c. So far this Author.

The other usual way both in Italy and other Countries, to conserve Snow and Ice with Straw or Reed, is set down so punctually by Mr. Boyle in his Experimental History of Cold, pag. 408. 409. that nothing is to be added. It seems Pliny could not pass by these Conservatories, and the cooling of drinks with Ice, without passing this severe, though elegant and witty, Animadversion upon them: Hi Nives, illi glaciem potant, poenasque montium in voluptatem gulae vertunt: Servatur algor aestibus, excogitaturque ut alienis mensibus nix algeat, lib. 19. cap. 4. But the Epigrammatist sports with it thus;

Non potare nivem, sed aquam potare rigentem De nive, commenta est ingeniosa sitis. Martial. 14. Ep. 117.

* * * * *

Directions for Sea-men, bound for far Voyages.

It being the Design of the R. Society, for the better attaining the End of their Institution, to study Nature rather than Books, and from the Observations, made of the Phaenomena and Effects she presents, to compose such a {141} History of Her, as may hereafter serve to build a Solid and Useful Philosophy upon; They have from time to time given order to several of their Members to draw up both Inquiries of things Observable in forrain Countries, and Directions for the Particulars, they desire chiefly to be informed about. And considering with themselves, how much they may increase their Philosophical stock by the advantage, which England injoyes of making Voyages into all parts of the World, they formerly appointed that Eminent Mathematician and Philosopher Master Rooke, one of their Fellowes, and Geometry Professor of Gresham Colledge (now deceased to the great detriment of the Common-wealth of Learning) to think upon and set down some Directions for Sea-men going into the East & West-Indies, the better to capacitate them for making such observations abroad, as may be pertinent and suitable for their purpose; of which the said Sea-men should be desired to keep an exact Diary, delivering at their return a fair Copy thereof to the Lord High Admiral of England, his Royal Highness the Duke of York, and another to Trinity-house to be perused by the R. Society. Which Catalogue of Directions having been drawn up accordingly by the said Mr. Rook, and by him presented to those, who appointed him to expedite such an one, it was thought not to be unseasonable at this time to make it publique, the more conveniently to furnish Navigators with Copies thereof. They are such, as follow;

1. To observe the Declination of the Compass, or its Variation from the Meridian of the place, frequently; marking withal, the Latitude and Longitude of the place, wherever such Observation is made, as exactly as may be, and setting down the Method, by which they made them.

2. To carry Dipping Needles with them, and observe the Inclination of the Needle in like manner.

3. To remark carefully the Ebbings and Flowings of the Sea, in as many places as they can, together with all the Accidents, {142} Ordinary and Extraordinary, of the Tides; as, their precise time of Ebbing and Flowing in Rivers, at Promontories or Capes; which way their Current runs, what Perpendicular distance there is between the highest Tide and lowest Ebb, during the Spring-Tides and Neap-Tides; what day of the Moons age, and at times of the year, the highest and lowest Tides fall out: And all other considerable Accidents, they can observe in the Tides, cheifly neer Ports, and about Ilands, as in St. Helena's Iland, and the three Rivers there, at the Bermodas &c.

4. To make Plotts and Draughts of prospect of Coasts, Promontories, Islands and Ports, marking the Bearings and Distances, as neer as they can.

5. To sound and marke the Depths of Coasts and Ports, and such other places nere the shoar, as they shall think fit.

6. To take notice of the Nature of the Ground at the bottom of the Sea, in all Soundings, whether it be Clay, Sand, Rock, &c.

7. To keep a Register of all changes of Wind and Weather at all houres, by night and by day, shewing the point the Wind blows from, whether strong or weak: The Rains, Hail, Snow and the like, the precise times of their beginnings and continuance, especiall Hurricans and Spouts; but above all to take exact care to observe the Trade-Winds, about what degree of Latitude and Longitude they first begin, where and when they cease, or change, or grow stronger or weaker, and how much; as near and exact as may be.

8. To observe and record all Extraordinary Meteors, Lightnings, Thunders, Ignes fatui, Comets, &c. marking still the places and times of their appearing, continuance. &c.

9. To carry with them good Scales, and Glasse-Violls of a pint or so, with very narrow mouths, which are to be fill'd with Sea-water in different degrees of Latitude, as often as {143} they please, and the weight of the Vial full of water taken exactly at every time, and recorded, marking withall the degree of Latitude, and the day of the Month: And that as well of water near the Top; as at a greater Depth.

* * * * *

Some Observations concerning Jupiter. Of the shadow of one of his Satellites seen, by a Telescope passing over the Body of Jupiter.

I have received an Account from very good hands, That on the 26^{th.} of September last, at half hour after seven of the Clock, was seen, both in Holland and in France (by curious Observers, with very good Telescopes) the shadow of one of the Satellites of Jupiter, passing over his Body. One of those small Stars moving about his Body (which are therefore called his Satellites) coming between the Sun and it, made a small Eclipse, appearing in the Face of Jupiter as a little round black Spot. The Particulars of those Observations, when they shall come to our Hands, we may (if need be) make them publik: Which Observations, as they are in themselves very remarkable, and argue the Excellency of the Glasses by which they were discovered; So are we, in part, beholding to Monsieur Cassini for them, who giving notice before hand of such Appearances to be expected, gave occasion to those Curious Observers to look for them.

* * * * *

Of a permanent Spot in Jupiter: by which is manifested the conversion of Jupiter about his own Axis.

Besides that Transient Shadow last mentioned, there hath been observed, by Monsieur Cassini, a permanent Spot in the Disque of Jupiter; by the help whereof, he hath been able to observe, not onely that Jupiter turns about upon his own Axis, but also the Time of such conversion; which he {144} estimates to be, 9 hours and 56 minutes.

For as Kepler did before conjecture, from the motion of the Primitive Planets about the Sun as their Center, that the Sun moved about its own Axis, but could not prove it, till by Galileo and Shiner the Spots in the Sun were discovered; so it hath been thought reasonable, from the Secundary Planets moving about Jupiter, that Jupiter is also moved about his Axis; yet, till now, it hath not been evinced by Observation, That it doth so move; much less, in what Period of Time. And the like reason there is to judge so of Saturn, because of the Secundary Planet discovered by Monsieur Hugens de Zulichem to move about it; (though such motion be not yet evinced from Observation:) as well as that of the Earth, from its Attendant the Moon.

Whether the same may be also concluded of the other Planets, Mars, Venus, and Mercury, (about whom have not yet been observed any Secondary Planets to move,) is not so evident. Yet there may be somewhat of like probability in those. Not onely, because it is possible they may have Secundary Planets about them, though not yet discovered; (For, we know, it was long after those of Jupiter, before that about Saturn was discovered; and who knows, what after times may discover about the rest?) But because the Primary Planets being all in like manner inlightned by the Sun, and (in all likely hood) moved by it; it is likely that they be moved by the same Laws and Methods; and therefore, turn'd about their own Axis, as it is manifest that some of them are.

But, as for the Secundary Planets, as well those about Jupiter, as that about Saturn; it is most likely that they have no such Rotation upon their Axis. Not so much because, by reason of their smalness, no such thing hath been yet observed, (or, indeed, could be, though it were true;) But because they being Analogical to our Moon, it is most likely that they are moved in like manner. Now, though it be {145} true, that there is some kind of Libration of the Moon's body, so that we have not precisely just the same part of it looking towards us; (as is evident by Hevelius observations, and others;) yet is there no Revolution upon its Axis; the same part of it, with very little alteration, always respecting us, as is to be seen in Hevelius his Tratise de Motu Lunae Libratorio, and indeed, by all those who have written particularly of the spots on the Moon; and is universally known to all that have with any curiosity viewed it with Telescopes.

* * * * *

Of some Philosophical and curious Books, that are shortly to come abroad.

1. Of the Origine of Forms and Qualities, deduced from Mechanical Principles; by the Honorable Robert Boyle Esq.

2. Hydrostatical Paradoxes, by the same. Both in English.

3. A Tract of the Origine of the Nile, by Monsieur Isaac Vossius, opposed to that of Monsieur de la Chambre, who is maintaining, That Niter is the principal cause of the Inundation of that River.

4. A Dissertation of Vipers, by Signor Redi, an Italian.

5. A Discourse of the Anatomy of a Lyon, by the same.

6. Another, De Figuris Salium, by the same.

7. A Narration of the Establishment of the Lyncei, an Italian Academy, and of their Design and Statutes: the Prince Cesi being the Head of them, who did also intend to establish such Philosophical Societies in all parts of the World, and particularly in Africa and America, to be by that means well informed of what considerable productions of Nature were to be found in those parts. The Author yet Anonymus.

8. To these I shall add, a Book newly Printed in Oxford (and not yet dispersed) being, A Catalogue of Fixed Stars with their Longitudes, Latitudes, and Magnitudes, according to the Observations of Uleg-Beig (a King, and famous Astronomer, who was Great-Grand-childe to the famous {146} Tamerlane, and one of his Successors in some of his Kingdoms) made at Samarcand, his cheief seat, (for the year of the Hegira 841, for the year of Christ 1427), who not finding the Tables of Ptolemy to agree sufficiently with the Heavens, did with great diligence, and expense, make observations anew; as Tycho Brahe hath since done. It is a small part of a larger Astronomical Treatise of his, whereof there be divers Persian Manuscript Copies in Oxford. Out of which this is Translated and Published, both in Persian and Latine, by Mr. Thomas Hyde, now Library Keeper to the Bodleyan Library in Oxford: (with Commentaries of his annexed:) Like as another part of it hath formerly been by Mr. John Graves. And it were a desirable work that the whole were Translated, that we might be the better acquainted with what was the Eastern Astronomy at that time.

* * * * *

Published with License.

Oxford, Printed by A: & L: Lichfield, for Ric: Davis. 1666.

{147}

* * * * *



Num. 9.

PHILOSOPHICAL TRANSACTIONS.

* * * * *

Munday, Feb. 12. 1665/6.

* * * * *

The Contents.

An Apendix to the Directions for Seamen, bound for far voyages. Of the judgment of some of the English Astronomers, touching the difference between two learned men, about an Observation made of the first of the two late Comets. Of a Correspondency, to be procured, for the finding out of the True distance of the Sun and Moon from the Earth. Of an Observation not long since made in England of Saturn. An Account of some Mercurial Observations, made with a Barometer, and their Results. Some Observations of Vipers, made by an Italian Philosopher.

* * * * *

An Appendix to the Directions for Seamen, bound for far Voyages.

Whereas it may be of good use, both Naval and Philosophical, to know, both how to sound depths of the sea without a Line, and to fetch up water from any depth of the same; the following waies have been contrived by Mr. Hook to perform both; (which should have been added to the lately printed Directions for Seamen, if then it could have been conveniently done.) {148}



First, for the sounding of depths without a Cord, consider Figure 1, and accordingly take a Globe of Firr, or Maple, or other light Wood, as A: let it be well secured by Vernish, Pitch, or otherwise, from imbibing water; then take a piece of Lead or Stone, D, considerably heavier then will sink the Globe: let there be a long Wire-staple B, in the Ball A, and a springing Wire C, with a bended end F, and into the said staple, press in with your fingers the springing Wire on the bended end: and on it hang the weight D, by its ring E, and so let Globe and all sink gently into the water, in the posture represented in the first Figure, to the bottom, where the weight D touching first, is thereby stopt; but the Ball, being by the Impetus, it acquired in descending, carried downwards a little after the weight is stopt, suffers the springing wire to fly back, and thereby sets it self at liberty to reascend. And, by observing the time of the Ball's stay under water (which may be done by a Watch, having minuts and seconds, or by a good Minut-glass, or best of all, by a Pendulum vibrating seconds) you will by this way, with the help of some Tables, come to know any depth of the sea.

Note, that care must be had of proportioning the weight and shape of the Lead, to the bulk, weight, and figure of the Globe, after such a manner, as upon experience shall be found most convenient.

In some of the Tryals already made with this Instrument, the Globe being of Maple-wood, well covered with Pitch to hinder soaking in, was 5-13/16 inches in diameter, and weighed 21/2 pounds: the Lead of 41/2 pounds weight, was of a Conical figure, 11. inches long, with the sharper end downwards, 1-9/16 inches at the top, and 1/16 at the bottom in diameter. And in those Experiments, made in the Thames, in the depth of 19. foot water, there passed between the Immersion and Emersion of the Globe, 6. seconds of an hour; and in the depth of 10. foot water, there passed 31/2 seconds or thereabout: From many of which kind of Experiments it will likely not be hard to finde {149} out a method to calculate, what depth is to be concluded from any other time of the like Globes stay under water.



In the same Tryals, made with this Instrument in the said River of Thames, it has been found, that there is no difference in time, between the submersions of the Ball at the greatest depth, when it rose two Wherries length from the place where it was let fall (being carried by the Current of the Tide) and when it rose within a yard or so of the same place where it was let down.

The other Instrument, for Fetching up water from the depth of the sea, is (as appears by Figure 2.) a square woodden Bucket C, whose bottoms EE, are so contrived, that as the weight A, sinks the Iron B, (to which the Bucket C, is fastned by two handles DD, on the ends of which are the moveable bottoms or Valves EE,) and thereby draws down the Bucket, the resistance of the water keeps up the Bucket in the posture C; whereby the water hath, all the while it is descending, a clear passage through; whereas, as soon as the Bucket is pulled upwards by the Line F, the resistance of the water to that motion beats the Bucket downward, and keeps it in the posture G, whereby the Included water is preserved from getting out, and the Ambient water kept from getting in.

By the advantage of which Vessel, it may be known, whether sea water be Salter at and towards the bottom, then at or near the top: Likewise, whether in some places of the sea, any sweet water is to be found at the bottom; the Affirmative whereof is to be met with in the East Indian Voyages of the industrious John Hugh Van Linsckoten, who page 16 of that Book, as 'tis Englished, records, that in the Persian Gulph, about the Island Barem, or Baharem, they fetch up with certain Vessels (which he describes not) water out of the sea, from under the salt-water, four or five fathom deep, as sweet, as any Fountain water. {150}

* * * * *

Of the Judgement of some of the English Astronomers, touching the difference between two learned men, about an Observation made of the First of the two late Comets.

[Sidenote: By Telescopical Stars are understood such, as are not seen, but by the help of a Telescope.]

Whereas notice has been taken in Num. 6. of these Transactions, that there was some difference between those two deservedly celebrated Philosophers, Monsieur Hevelius and Monsieur Auzout, concerning an Observation, made by the former of them, on the 8/18 of February 1665. & that thereupon some Eminent English Astronomers, considering the importance of the dispute, had undertaken the examination thereof; it will, 'tis conceived, not be unacceptable to such, as saw those Papers, to be informed, what has been done and discerned by them in that matter. They having therefore compared the Printed Writings of the two Dissenters, and withall consulted the observations made with Telescopes at home, by some of the most intelligent Astronomers amongst them, who have attentively observed the Position of that Comet to the Telescopical stars, that lay in its way; Do thereupon Joyntly conclude, that, whatever that Appearance was, which was seen near the First Star of Aries, by Monsieur Hevelius (the truth of whose relation concerning the same, they do in no wise question) the said Comet did not come neer that Star in the left Ear of Aries, where the said M. Hevelius supposes it to have passed, but took its course neer the Bright Star in its Left Horn, according to Bayers Tables. And since that the Observations of judicious both French, Italian, & Dutch Astronomers (as many of them, as are come to the knowledge of the English) do in the main fully agree with theirs, they do not at all doubt, but that, there being such an unanimous {151} consent in what has been just now declared, & the Controversie being about Matter of fact, wherein Authority, Number, and Reputation must cast the Ballance, Mons. Hevelius, who is as well known for his Ingenuity, as Learning, will joyn and acquiesce in that sentiment.

* * * * *

Of a correspondency, to be procured, for the Finding out the True distance of the Sun and Moon from the Earth, by the Paralax, observed under (or neer) the same Meridian.

Seeing that the knowledge of this distance may prove of important Use, for the Perfecting of Astronomy, and for the better establishing the doctrine of Refractions, it is in the thoughts of some very curious Persons in England, for the finding out the same, to settle a Correspondency with some others abroad, that are understanding in Astronomical matters, and live in places farr distant in Latitude, and under (or near) the same Meridian.

To perform which, the following Method is proposed to be observed; viz. That at certain times agreed on by two Observatours, making use of Telescopes, large, good and well fitted for this purpose, by a measuring rod, placed within the Eye glass at a convenient distance, that it may be distinctly seen, and serve for measuring small distances by minuts and seconds (which is easie enough in large Telescopes) that, I say, each of such observers, thus furnish't shall observe the visible way of the Moon among the Fixt Stars, (by taking her exact distance from any Fixt Starr, that lyes in or very near her way, together with the exact time of her so appearing) and the then apparent Diameter of her Disk; continuing these Observations every time for two or three hours; that so, {152} if possible, two exact observations of her Apparent place among the Fixt Stars being made, at two places thus distant in Latitude, and as near as may be under the same Meridian, by these Observators concurring at the same time, her true and exact distance may be hence collected, not onely for that time, but at all other times, by any single Observator's viewing her with a Telescope, and measuring exactly her Apparent Diameter. It were likewise desirable, that as often as there happens any considerable Eclipse of the Sun, that this also might be observed by them, noting therein the exact measure of the greatest Obscuration compared with the then Apparent Diameter of his Disk. For by this means, after the distance of the Moon hath been exactly found, the distance of the Sun will easily be deduced.

As for the time, fittest for making Observations of the Moon, that will be, when she is about a Quarter or somewhat less illuminated, because then her light is not so bright, but that with a good Telescope she may be observ'd to pass close by, and sometimes over several Fixt Stars; which is about four or five days before or after her Change: Or else at any other time, when the Moon passes near or over some of the bigger sort of Fixt Stars, such as of the first or second Magnitude; which may be easily calculated and foreseen: Or best of all, when there is any Totall Eclipse of the Moon; for then the smallest Telescopical Stars may be seen close adjoyning to the very body of the Moon. Of all which particulars the two Correspondents are to agree, as soon as he, that is to joyn abroad, shall be found out; whereupon they are mutually to communicate to each other, what they shall have thus observed in each place.

* * * * *

Of an Observation, not long since made in England, of Saturn.



This Observation was made by Mr. William Ball, {153} accompanied by his brother, Dr. Ball, October 13. 1665. at six of the Clock, at Mainhead near Exeter in Devonshire, with a very good Telescope near 38 foot long, and a double Eye-glass, as the observer himself takes notice, adding, that he never saw that Planet more distinct. The observation is represented by Figure 3. concerning which, the Author saith in his letter to a friend, as follows; This appear'd to me the present figure of Saturn, somewhat otherwise, than I expected, thinking it would have been decreasing, but I found it full as ever, and a little hollow above and below. Whereupon the Person, to whom notice was sent hereof, examining this shape, hath by Letters desired the worthy Author of the Systeme of this Planet, that he would now attentively consider the present Figure of his Anses or Ring, to see whether the appearance be to him, as in this Figure, and consequently whether he there meets with nothing, that may make him think, that it is not one body of a Circular Figure, that embraces his Diske, but two.

And to the end that other Curious men, in other places might be engaged, to joyn their Observations with him, to see, whether they can find the like appearance to that, represented here, especially such Notches or Hollownesses, as at A and B, it was thought fit to insert here the newly related Account.

* * * * *

A Relation of some Mercurial Observations, and their Results.

Modern Philosophers, to avoyd Circumlocutions, call that Instrument, wherein a Cylinder of Quicksilver, of between 28. and 31. Inches in Altitude, is kept suspended after the manner of the Torricellian Experiment, a Barometer or Baroscope, first made publick by that Noble Searcher of Nature, Mr. Boyle, and imployed by Him and others, to detect all the minut variations in the Pressure and weight of the Air. For the more {154} curious and nice distinguishing of which small changes, Mr. Hook in the Preface to his Micrography, has described such an Instrument with a Wheel, contrived by himself, and, by these two last years trials of it, constantly found most exact for that purpose: which being so accurate, and not difficult to be made, it were desirable, that those who have a Genius and opportunities of making Observations of this kind, would furnish themselves with such of these Instruments, as were exactly made and adjusted according to the Method, delivered in the newly mentioned place.

To say something of the Observations, made by this Instrument, and withal to excite studious Naturalists to a sedulous prosecution of the same, the Reader may first take notice, that the lately named Mr. Boyle hath (as himself not long since did intimate to the Author of these Tracts) already made divers Observations of this kind in the year 1659. and 1660. before any others were publick, or by him so much as heard of; though he has hitherto forborn to divulge them, because of some other Papers (in whose Company they were to appear) which being hindred by other studies and employments, he hath not as yet finished.

Next, that, besides several others, who, since have had the curiosity of making such observations, the Worthy and Inquisitive Dr. John Beal, is doing his part with much assiduity (of which he hath by several Letters acquainted his Friends in London) both by observing himself, and by procuring many Correspondents in several places in England for the same purpose; judging it of great importance, that Observations of this kind be made in parts somewhat distant from one another, that so from many of those, accurately made and then compared, it may be discovered, whether the Aire gravitates more in the parts of the Earth lying more East or West, North or South? whether on such as lie neerer to the Sea, or further up into the Mainland? in hotter or colder weather? whether in {155} high Winds or Calms? whether in wet weather or dry? whether most when a North, or when a South, when an East or a West wind blows? and whether it keeps the same seasons of Changes? and whether the seasons and changes of the Air and Weather can be thereby discover'd, and the now hidden causes of many other Phaenomena detected?

The said Doctor is so much pleased with the discovery already made by the help of this Instrument, that he thinks it to be one of the most wonderful that ever was in the World, if we speak of strangeness, and just wonder, and of Philosophical importance, separate from the interest of lucre. For (saith he in one of his Letters) who could ever expect, that we men should find an Art, to weigh all the Air that hangs over our heads, in all the changes of it, and, as it were, to weigh, and to distinguish by weight, the Winds and the Clouds? Or, who did believe, that by palpable evidence we should be able to prove, the serenest Air to be most heavy, and the thickest Air, and when darkest Clouds hang neerest to us, ready to dissolve, or dropping, then to be lightest. And though (so he goes on) we cannot yet reach to all the Uses and Applications of it, yet we should be entertain'd for a while, by the truly Honourable Mr. Boyle, as the leading person herein, upon the delight and wonder. The Magnet was known many hundreds of years before it was applied to find out New Worlds. To me (saith he) tis a wonderful delight, that I have alwaies in my Study before my eye such a Curious Ballance.

Having thus in General expressed his thoughts about this Invention, and the singular pleasure, he takes in the Observations made therewith, he descends to particulars, and in several Letters communicates them to his Correspondent, as follows:

[Sidenote: The Exclusion of all Air is here necessary, because Air being subject to the operation of Heat and Cold, if any of it remain in the Barometer, it will cause it to vary from shewing the true Pressure of the Air.]

1. My Wheel-barometer I could never fill so exactly with Mercury as to exclude all Air; and therefore I trust more {156} to a Mercurial Cane, and take all my Notes from it. This Cane is but 35. Inches long, of a very slender Cavity, and thick Glass. This may easily be conveyed to any place, for Trials. The Vessel for the stagnating Mercury, into which the said Cane is immersed, is about two Inches wide. The Mercury so well fill'd, that for some daies it would not subside, but hung to the top of the Glass-cane. I keep it in a Closet pretty close, 9. foot high, 8. foot broad, 15. foot long; neer a Window. This I note, because possibly the closeness of the room may hinder, that it gives not the full of all Changes, as it might in a more passable Air.

2. In all my Observations from May 28. 1664 to this present (December 9. 1665.) the Quicksilver never ascended but very little above 301/4 Inches.

3. It ascended very seldom so high (videl. to 301/4 Inches) chiefly Decemb. 13. 1664. the weather being fickle-fair, Evening.

4. I find by my Calender of June 22. 1664. at 5. in the Morning, in a time of long setled fair weather, that the Mercury had ascended about half an Inch higher then 30: but I fear some mistake, because I then took no impression of wonder at it; yet for 3. or 4. daies, at that time it continued high, in well-setled, fair and warm weather; most part above 30. Inches. So that I may note, the Mercury to rise as high in the hottest Summer, as in the coldest Winter-weather.

[Sidenote: Perhaps this is from some included Air.]

5. Yet surely I have noted it ascend a little higher for the Coldness of the Weather; and very frequently, both in {157} Winter and Summer to be higher in the cold Mornings and Evenings, then in the warmer Mid-day.

6. Generally in setled and fair weather both of Winter and Summer, the Mercury is higher, than a little before or after, or in Rainy weather.

7. Again, generally it descended lower after Rain, than it was before Rain.

[Sidenote: It seems these were Easterly winds.]

8. Generally also it falls in great winds; and somewhat it seem'd to sink, when I open'd a wide door to it, to let in stormy winds; yet I have found it to continue very high, in a long stormy wind of 3. or 4. daies.

9. Again, generally it is higher in an East and North-wind. (Caeteris paribus) than in a South and West-wind.

10. I tryed several times, by strong fumes and thick smoaks to alter the Air in my Closet; but I cannot affirm, that the Mercury yielded any more, then might be expected from some increase of heat. Such as have exact Wheel-Barometers, may try whether Odors or Fumes do alleviate the Air.

11. In this Closet I have not in all this time found the extreamest changes of the Quicksilver to amount to more, than to 23/4, or to 2-7/8. inches, at most.

12. Very often I have found great changes in the Air, without any perceptible change in the Barometer; as in the dewy nights, when the moisture descends in a great quantity, and the thickness sometimes seems to hide the Stars from us: In the days foregoing, and following, the Vapors have been {158} drawn up so Invisibly, that the Air and Sky seem'd very clear all day long. This I account a great change between ascending and descending Dews and Vapors (which import Levity and Weight,) and between thick Air and clear Air: which changes do sometimes continue in the Alternative course of day and night, for a week or fortnight together; and yet the Baroscope holding the same.

13. Sometimes (I say not often) the Baroscope yields not to other very great changes of the Air. As lately (December 18.) an extraordinary bright and clear day; and the next following quite darkened, some Rain and Snow falling; but the Mercury the same: so in high winds and calms the same.

14. I do conceive, that such as converse much Sub dio, and walk much abroad, may find many particulars much more exactly, then I, who have no leisure for it, can undertake. To instance in one of many, December 16. last, was a clear cold day, very sharp and strong East wind, the Mercury very near 30. inches high, about three in the afternoon, I saw a large black cloud, drawing near us from the East and South-East, with the East-wind. The Mercury changed not that day nor the day following; the Stars and most of the sky were very bright and clear till Nine of the Clock; and then suddenly all the sky was darkned, yet no change of weather happened; December 17. the frost held, and 'twas a clear day, till about two of the clock in the afternoon; and then many thick clouds appear'd low in the West; yet no change of the weather here; the Wind, Frost, and Quick-silver, the same, December 18. the Mercury fell almost 1/4 of an inch, and the sky and Air so clear and bright and cold with an East-wind, that I wondred what could cause the Mercury to descend. I Expected, it should have ascended, as usually it does in such clear skys. Casually I sent my servant abroad, and he discovered the remote Hills, about 20. miles off, cover'd with {159} snow, This seem'd to manifest, that the Air, being discharged of the clouds by snow, became lighter.

15. I have seldom seen the change to be very great, at any one time. For, though I do not now take a deliberate view of my Notes, yet I wonder'd once to see, that in one day it subsided about 3/4 of an inch.

16. Of late I have altered my Method upon the Barometer, observing it, as it is before my Eyes, all day long, and much of the night, being watchful for the moments of every particular change, to examine, what cause in the Air and Heavens may appear for such changes. And now my wonder is, to see, how slow it is, it holding most between the nine and twentieth and thirtieth inch of late.

17. I must now (January 13. 1665/6) tell you, that the Mercury stands at this time (as it did also yesterday) a quarter above 30. inches; yet both days very dark and cloudy, sometimes very thick and misty Air; which seldom falls out. For, for the most part, I see it higher in clearest setled weather, than in such cloudy and misty Foggs. This thick Air and darkness hath lasted above a week; lately more Cold, and East and North-East wind.

[Sidenote: This seems to be wished, because the motion of the Mercury may be more free in a wider Cane.]

Thus far the Notes of this Observing Divine; of which Mr. Boyle, to whom they were also communicated, entertains these thoughts, that they seem to him very faithfully made, and do for the main, agree well enough with his observations, as far as he remembers, not having them, it seems, at that time, when he wrote this, at hand; and though it be wished by him, that the Observer's Glass-Cane had been somewhat bigger; yet his diligence in fitting it so carefully, or rather so skilfully, as is above-mentioned, is much by him commended. {160}

* * * * *

Some Observations of Vipers.

A curious Italian, called Francesco Redi, having lately had an opportunity, by the great number of Vipers, brought to the Grand Duke of Toscany for the composing of Theriac or Treacle, to examine what is vulgarly delivered and believed concerning the Poyson of those Creatures, hath, (according to the account, given of it in the French Journal des Scavans, printed January 4. 1665/6) performed his undertaking with much exactness, and published in an Italian tract, not yet come into England, these Observations.

1. He hath observed, that the poyson of Vipers is neither in their Teeth, nor in their Tayle, nor in their Gall: but in the two Vesicles or Bladders, which cover their teeth, and which coming to be compressed, when the Vipers bite, do emit a certain yellowish Liquor, that runs along the teeth and poysons the wound. Whereof he gives this proof, that he hath rub'd the wounds of many Animals with the Gall of Vipers, and pricked them with their Teeth, and yet no considerable ill accident follow'd upon it, but that as often as he rubbed the wounds with the said yellow Liquor, not one of them escaped.

2. Whereas commonly it hath hitherto been believed, that the poyson of Vipers being swallowed, was present death; this Author, after many reiterated Experiments, is said to have observed, that in Vipers there is neither Humour, nor Excrement, nor any part, not the Gall it self, that, being taken into the Body, kills. And he assures, that he hath seen men eat, and hath often made Bruit Animals swallow all that is esteem'd most poysonous in a Viper, yet without the least mischief to them. Whence he shews, that it needs not so much to be wondred at, that certain Empiricks swallow the juyce of the {161} most venomous Animals without receiving any harm thereby; adding, that, which is ascribed to the vertue of their Antidote, ought to be attributed to the nature of those kinds of Poysons, which are no poysons, when they are swallow'd, (for which Doctrine he also alledges Celsus) but onely when they are put into wounds. Which also has been noted by Lucan, who introduces Cato thus speaking;

Noxia serpentum est admisto sanguine pestis, Morsu virus habent, & fatum dente minantur; Pocula morte carent.

And what also some Authors have affirm'd, videl. That it is mortal, to eat of the Flesh of creatures killed by Vipers; or to drink of the Wine wherein Vipers have been drowned; or to suck the wounds that have been made by them, is by this Authour observed to be wide of truth. For he assures, that many persons have eaten Pullets and Pigeons, bitten by Vipers, without finding any alteration from it in their health. On the contrary, he declares, That it is a soveraign Remedy against the biting of Vipers, to suck the wound; alledging an Experiment, made upon a Dog, which he caused to be bitten by a Viper at the nose, who by licking his own wound saved his life. Which he confirms by the example of those people, celebrated in History by the name of Marsi and Psilli, whose Employment it was, to heal those, that had been bitten by Serpents, by sucking their wounds.

3. He adds, that although Galen and many modern Physitians do affirm, that there is nothing, which causeth so much thirst, as Vipers-flesh, yet he hath experimented the contrary and knows divers persons, who did eat the flesh of Vipers at all their meals, and yet did assure him, they never were less dry, then when they observed that kind of Diet.

4. As for the Salt of Vipers, whereof some Chymists have {162} so great esteem, he saith, that it hath no Purging vertue at all in it; adding that even of All Salts, none hath more vertue than another, as he pretends to have shew'd in an other Book of his, De natura salium; which also hath not been yet transmitted into these parts.

5. He denies, what Aristotle assures, and what Galen saith to have often tryed, that the Spittle of a Fasting person kills Vipers; and he laughs at many other particulars, that have been delivered concerning the Antipathy of Vipers unto certain things; and their manner of Conception and Generation, and several other properties, commonly ascribed to them; which the alledged French Author affirms to be refuted by so many experiments made by this Italian Philosopher, that it seems to him, there is no place left for doubting, after so authentick a testimony.

* * * * *

Advertisement.

The Reader of these Transactions is desired to correct these Errata in Number 8. viz. page. 132. line penult. read Wine for Lime; and page 133. line 10. read Thresher for Trepher, as some Copies have it; and page 136. line ult. read purifie for putrifie.

* * * * *

LONDON,

Printed for John Martyn and James Allestree, Printers to the Royal Society. 1666.

{163}

* * * * *



Num. 10.

PHILOSOPHICAL TRANSACTIONS.

* * * * *

Munday, March 12. 1665/6.

* * * * *

The Contents.

Observations continued upon the Barometer, or Ballance of the Air. A Relation concerning the Earth-quake neer Oxford; together with some Observations of the sealed Weatherglass and Barometer thereupon by Dr. Wallis. A more full and particular Account of those Observations about Jupiter, that were mention'd in Numb. 8. An Account of some Books, lately publisht, videl. Mr. Boyles Hydrostatical Paradoxes; Steno de Musculis & Gladulis; De Graeff de Natura & Usu Succi Pancreatici.

* * * * *

Observations continued upon the Barometer, or rather Ballance of the Air.

These Transactions being intended, not only to be (by parcels) brief Records of the Emergent Works and Productions in the Universe; Of the Mysteries of Nature of later discoveries; And, of the growth of Useful Inventions and Arts; but also, and chiefly, to sollicite in all parts mutuall Ayds and Collegiate endeavours for the farther advancement thereof: We shall begin this Second year of our Publications in this kind (in which, for 3-moneths the Printing-presses were interrrupted by the publick Calamity) with a few more particular Observations upon the Ballance of the Air, as they are most happily invented and directed by Mr. Boyle; and deserve to be prosecuted with care and diligence in all places.

But it is to be premised, that the Worthy person, who was alledged as the Author of the Observations, delivered of this kind in the last of these Tracts (Dr. Beale) gives notice, That {164} he did not pretend to exactness, but only to excite the carefulness of others in the several distant places, and chiefly such, as can have the assistance of a Wheel-ballance perfectly filled: without both which aids he hopes not to obtain all the benefits and mysteries of this Invention.

This being thus briefly intimated, the Account of the Observations themselves, as they were extracted out of a late Letter of the same Person, are, as followes:

[Sidenote: _Hygroscopes_ are Instruments, to discover the degrees of Moisture and Drought of the Air._]

1. As I have fitted and filled the Single Cane, I can say in the general, That I have not yet found any such infallible Prognostick of these changes of weather, which do follow a long serenity, or setled weather. And perchance in brighter Climats it may be constantly infallible. In these Northern Islands, the Clouds are so short, and narrow, and by fickle changes are sometimes emptied upon us, sometimes so neer, as may make so little variation in the weight of the whole Atmosphere of Air, as may sometimes deceive us, or smother and hide from us the causes of fixedness, or of changes. I wish I could see a good Calendar or Journal taken in taken in Tangier, and in some of our Northern and most Southern parts of America. I have store of Hygroscopes of divers kinds; and I do remark them, and the sweatings of Marble, and as many other famed Prognosticks, as I can hear off; but can find nothing so neerly indicative of the change of weather, as this Ballance. Those others are often changed by Dews, which do not at all alter the Ballance, nor alter the state of the weather: And the open Weather-glass is known to signifie nothing at certainty, having a double obedience to two Masters, sometimes to the Weight of the Air, sometimes to Heat, as the service is commanded.

2. And in further confirmation of this Note, I may adde to the former, That in January last 1665/6, from the fourth, and more especially from the seventh day, for many daies it continued very dark, so that all men expected daily great rain; yet the Mercury held very high, neer to the greatest height; And though in those daies sometimes thick mists arose, and some small rain fell, yet the Quick-silver held at a great height: which did indicate to me, there could then be no great change of weather. As the small rain fell, it yeilded somewhat, not much; and that does more {165} confirm the indication. And more lately, in very dark daies, I had the same confidence upon the same ground, and I was not disappointed.

3. Again, if the Mercury ascends to a good height after the fall of rain (as sometimes, but less often it does) then I look for a setled serenity; but if it proceeds after rain in a descending motion, then I expect a continuance of broken and showry weather. But in all, as I only say, For the most part, so I dare not positively declare it an affirmative result, but do refer it to the remarks of others. And this may explicate the Notes 6. and 14 of Num. 9. into more clearness.

4. That we find the Weather and our Bodies more chill, cold, and drooping, when the Mercury is lowest, and the Air lightest, besides other causes, I guess, That as Air is to us the breath of life, as water is to Fishes; so, when we are deprived of the usual measure of this our food, 'tis the same to us, as when the water is drawn ebb from Fishes. But I would much rather be instructed by others, then offer much in this kind.

5. The lowest descent of the Mercury in all the time, since I have observed it, was Octob. 26. 1665. in the Evening, when it was very near at 271/2 Inches. Which I find thus circumstanced with the weather in my notes.

Oct. 25. Morning; Mercury at 281/2 Inch. Great storms and much rain.

Oct. 26. Morning; Merc. at 28. winds quiet, thick dark clouds.

Oct. 26. Evening; Merc. at 271/2. That day, and some daies following, the weather was variable, frequent rain, and as you see, the Mercury lower, than usual.

6. Over the place, where this Mercurial Cane stands, I have set a Wind vane, with purpose of exactness, of a Streamer in Brass so large, and pointing to a Board indented in the Margin, that I can at a sure Level upon the Vane, take every of the 32. points of the Wind, half points, and quarter points, at good distance. Otherwise we may find our guesses much deceived, as the best guessers, upon trial, do acknowledge. And this exactness may become the Wheel-ballance, which shews the minutest variations almost beyond imagination. And thus any servant, at the approach of a thick Cloud, or other Meteor, higher or lower, or at the rising of a storm or fresh wind in the night, or day, may bring a report of the Weight of the Air, as certainly and almost as {166} easily, as of the Sun from the Dial in a Sunshine. It were good to have an Index of Winds, that discover'd as well their Ascent and Descent, as their Side-coastings.

* * * * *

A Relation concerning the late Earthquake neer Oxford; together with some Observations of the sealed Weatherglass, and the Barometer both upon that Phaenomenon, and in General.

This Relation was communicated by the excellently learned Dr. Wallis, as follows:

On the 19. of January 1665. Stylo Angliae (or Jan. 29. 1666. stylo novo) at divers places neer Oxford, was observed a small Earthquake (as at Blechington, Stanton-St. Johns, Bril, &c.) towards evening. In Oxford it self, I doe not hear, that it was observ'd to be an Earthquake; yet I remember about that time (whether precisely then or not; I cannot say) I took notice of some kind of odde shaking or heaving I observed in my study, but did impute it to the going of Carts or Coaches, supposed to be not far off; though yet I did take notice of it, as a little differing from what is usual on such occasions; (and wondered the more, that I did not hear any:) But not knowing, what else to refer it to, I thought no more of it. And the like account I have had from some others in Oxford, who yet did not think of an Earth-quake; it being a rare thing with us. Hearing afterwards of an Earthquake observed by others; I looked on my Notes concerning my Thermoscope and Baroscope, to see if any alteration considerable had then happened.

My Thermoscope consists of a round large Glass, containing about half a pint or more; from whence issues a long Cylindrical neck of Glass, about two foot and a half in length, and less than a quarter of an inch diameter; which neck was hermetically sealed at the top, to exclude communication with the External Air; but before the sealing of it, the whole Glass was filled with Spirit of Wine (tinged with Cochineel, to make it the more discernable to the Eye) so warmed, that it filled the whole content of the Glass; but afterwards, as it cooled, did so subside, as to leave a void space in the upper part of the Neck. Which Instrument, so prepared, doth by the rising or falling of the tinged liquor in the neck (consequent upon the expanding or contracting of the whole liquor contained in it and the Ball below) give a very nice account of the Temperature of the Air, {167} as to Heat or Cold: Even so nice, as that my being or not being in my Study I find to vary its hight sometimes almost a quarter of an inch.

My Baroscope, I call another Instrument for estimating the Weight or Pressure of the Incumbent Air, consisting of a long Glass-tube of about 4. foot in length, and about a quarter of an inch Bore: which tube (hermetically sealed at the one end) being filled with Quicksilver (according to the Torricellian Experiment) is inverted, so as to have the open end of it immersed in Stagnant Quicksilver, contained in a larger Glass under it, exposed to the pressure of the outward Air: Out of which open end (after such immersion) the Quicksilver in the Tube being suffered to run out, as much as it will, into the Stagnant Quicksilver, in which that mouth or open end is immersed, there is wont to remain (as is commonly known to those acquainted with this Experiment) a Cylinder of Quicksilver suspended in the Tube, about 28, 29, or 30. inches high; measuring from the surface of the Stagnant Quicksilver perpendicularly; (but more or less, within such limits, according as the Weight or Pressure of the Air incumbent on the External Stagnant Quicksilver exposed to it, is greater or less:) leaving the upper part of the Tube void. (Both which Instruments being the contrivance of the Honourable Robert Boyle, they are by him more particularly described in his Physico-Mechanical Experiments touching the Air, Exper. 17. and 18. and in his Thermometrical Discourses, premised to his History of Cold.)

Now, according to both these Instruments, having kept a daily Register of Observations for more than a whole year (saving when I have been for some short time absent from home) I find my Notes for that day to be these.

January. Thermoscope. Baroscope. 1665/6. Day. Hour. inches. inches. 19. 8. Morn. 14-1/16. 29-1/2. Hard frost. Close. 4. Even. 14-3/8. 29-1/4. Hard frost. Cloudy. 9. Even. 14-3/4. 29-3/4. Rain. Wind 20. 8. Morn. 15-1/4. 28-3/4. Sunshine. Wind.

So that, there being in the morning (January 19.) a hard frost (which began the day before about 4. of the Clock in the {168} afternoon (Jan. 18.) and continued (with us) till about 5. of the Clock in the afternoon of that day, Jan 19. with some fierceness) and the weather, Jan. 19. being in the morning, close; and cloudy all the day, with little of Sun-shine; the Liquor in the Thermoscope was very little raised, by 4. of the Clock afternoon, that is, but 5/16 of an inch (which, had the Sun shone, would, it's likely, have been near an Inch:) and after that time (or somewhat before) had there been no considerable change of weather, it would upon the Sun's setting have fallen (and probably so it did, till about 5. of the Clock, though I took no Observation in the interim.) But, contrary to what would have been expected, it was at 9. of the Clock at night, higher by 1/8 of an inch, than it had been at 4. occasioned by the change of weather, the Frost suddenly breaking, with us, between 5. and 6. of the Clock; about which time also it began to rain, and continued raining that Evening and good part of the Night. And the next morning I found the Liquor yet higher by half an inch, vid. 151/4 inches: (by reason of the Air that night being so much warmer, than it had been the day before;) whereas commonly it is considerably lower in the morning, than over night.

As to the Baroscope, for the Weight or Pressure of the Air; I find, that for the 11, l2, 13, 14, 15, 16, and 17. dayes, the Mercury in the Tube, was (by the ballancing Pressure of the incumbent Air on the stagnant Quicksilver, exposed to it) kept up to the height of near 30. Inches above the surface of the External Quicksilver, (though with some little variation, as 30, 29-15/16, 29-7/8, 29-13/16 but never so low, all that time, as 293/4;) which is the greatest height I have know it at, (for I do not find that I have ever, till then, observed it to be, in my Glasses, full 30. Inches, though it have been very near it:) the Weather having been almost continually Foggy, or very thick Mists, all that time. January 18. it came down to 293/4, in the forenoon; and afternoon, to 29-11/16. about the time the frost began: And Jan. 19. it was, at 8. in the morning, come down to 291/2; at 4. in the afternoon, to 291/4. But at 9. in the evening (when the Earth quake had intervened) it was risen half an inch, vid. to 293/4. And, by the next morning, fallen again a whole inch, vid. to 283/4; which fall I attribute (at least in part) to the rain that fell in the night.

This being what I observed out of my Register of these Instruments, (which, if I had then thought of an Earthquake, I {169} should have more nicely watched) what I have further gathered from Reports, is to this purpose.

I hear, it was observed at Blechington, above 5. miles to the North of Oxford, and so along by Bostol, Horton, Stanton-St. Johns, and so towards Whately, which is about 4. miles Eastward from Oxford. Not at all these places at the same time, but moving forward from Blechington towards Whately. For it was at Stanton about 6. of the Clock or later (as I understand from Mr. Boyle, who was there at that time;) but had been at Blechington a good while sooner. And I am told, that it was taken notice of by Doctor Holder (a Member of our Society) who was then at Blechington, to be observed by those in the further part of the Garden, some very discernable time before it was observed by those in the House; creeping forward from the one place to the other. What other places in the Country it was observed at, I have not been informed: but at Oxford (which, it seems, was about the skirts of it) it was so small, as would have been hardly noted at all, had not the notice, taken of it abroad, informed us of it.

Upon this Occasion, it will not be unseasonable to give some General accounts of what I have in my Thermoscope and Baroscope observed.

My Thermoscope, being fitted somewhat at adventures, I have found at the lowest to be somewhat more than 12. inches high, in the fiercest time of the long Frost in the beginning of the last year 1665. and about 27. Inches high, at the highest, in the hottest time of the last Summer: (which I mention, that it may appear at what temperature in proportion, the Air was at the time above-mentioned.) But I must add withall, that this standing so, as never to be exposed to the Sun, but in a room, that has a window only to the North, it would have been raised much higher than 27. inches, if it were put in the hot Sun-shine in Summer; this, as it is placed, giving therefore an account onely of the Temperature of the Air in general, not of the immediate heat of the Sun-shine.

This Instrument, thus situated, when it is about 15. inches, or lower, is for the most part hard frost; but seldom a frost, if higher than 16. Yet this I have often observed, that the Air by the Thermoscope has appeared considerably colder (and the liquor lower) at sometimes when there is no Frost, than at some other times, when the Frost hath been considerably hard. {170}

In my Baroscope, I have never found the Quicksilver higher than 30. inches, nor lower than 28. (at least, scarce discernably, not 1/16 of an inch higher than that, or lower than this;) which I mention, not only to shew the limits, within which I have observed mine to keep, vid. full 2 inches, but likewise as an Estimate of the Clearness of the Quicksilver from Air. For, though my Quicksilver were with good care cleansed from the Air; yet I find that which Mr. Boyle useth, much better: for, comparing his with mine at the same times, and both in Oxford, at no great distance; I find his Quicksilver to stand alwaies somewhat higher than mine (sometimes neer a quarter of an Inch;) which I know now how to give a more probable account off, than that my Quicksilver is either heavier than his; or else, that his is better cleansed from Air, (unless, possibly, the difference of the Bore, or other circumstances of the Tube, may cause the alteration; mine being a taller Tube, and a bigger Bore, than his.) And upon like reason, as his stands higher than mine; so another less cleansed from Air, may at the same time be considerably lower, and consequently under 28. Inches at the lowest.

In thick foggy weather, I find my Quicksilver to rise; which I adscribe to the heaviness of the Vapours in the Air. And I have never found it higher, than in the foggy weather above-mentioned.

In Sunshiny weather it riseth also (and commonly the clearer, the more;) which, I think, may be imputed partly to the Vapors raised by the Sun, and making the Air heavier; and partly to the Heat, increasing the Elastick or Springy power of the Air. Which latter I the rather add, because I have sometimes observed in Sunshiny weather, when there have come Clouds for some considerable time (suppose an hour or two) the Quicksilver has fallen; and then, upon the Suns breaking out again, it has risen as before.

In Rainy weather, it useth to fall (of which the reason is obvious, because the Air is lightned, by so much as falls:) In Snowy weather, likewise, but not so much as in Rain. And sometimes I have observed it, upon a Hoar-frost, falling in the night.

[Sidenote: * The Author of these Observations intends hereafter more particularly to observe, from what points those Winds blow, that make the Quicksilver thus subside.]

For Windy weather, I find it generally to fall; and that more universally, and more discernably, than upon Rain: (which I attribute to the Winds moving the Air collaterally, and thereby not suffering it to press so much directly downwards: the like of {171} which we see in swimming, &c.) And I have never found it lower than in high Winds.*

I have divers times, upon discerning my Quicksilver to fall without any visible cause at home, looked abroad; and found (by the appearance of broken Clouds, or otherwise) that it had rained not far off, though not with us: Whereupon, the Air being then lightened, our heavier Air (where it rained not) may have, in part, discharged it self on that lighter.

* * * * *

A more particular Account of those Observations about Jupiter, that were mentioned in Numb. 8.

Since the publishing of Numb. 8. of these Transactions, where, among other particulars, some short Observations were set down touching both the shadow of one of Jupiter's Satellits, passing over his Body, and that Permanent Spot, which manifests the Conversion of that Planet about his own Axis; there is come to hand an Extract of that Letter, which was written from Rome, about those Discoveries, containing an ample and particular Relation of them, as they were made by the Learned Cassini, Professor of Astronomy in the University of Bononia. That Extract, as it is found in the French Journal des Scavans of Febr. 22. 1666. we thus English.

Monsieur Cassini, after he had discovered (by the means of those Excellent Glasses of 50. palmes, or 35. feet, made by M. Campani) the Shadows, cast by the 4 Moons or Satellits of Jupiter upon his Diske, when they happen to be between the Sun and Him; after he had also distinguished their Bodies upon the Diske of Jupiter; made the last year some Praedictions for the Months of August and September, noting the dayes and hours, when the Bodies of the said satellits and their Shadows should appear upon Jupiter, to the end that the Curious might be convinced of this matter by their own Observations.

Some of these Praedictions have been verified not only at Rome, and in other places of Italy, but also at Paris by M. Auzout, the most Celebrated and the most Exact of our Astronomers; and in Holland, by M. Hugens. And we can now doubt no longer, of the rotation of the Satellits about Jupiter, as the Moon turns about the Earth; nor believe, that Jupiter or his Attendants have any other Light, than that, which they receive from the Sun; as some did {172} assure before these Observations. There remained to find by Experience, whether Jupiter did turn about his Axis, as many believe, that the Earth turns about her's. And although most Astronomers had conjectur'd, it did so, either by this Analogy, or by other Congruities, yet it was much wish'd, that we might be assured thereof by Observations. And this it is, for which we are obliged to M. Cassini, who, having by the advantage of the same Glasses discover'd several changes, as well in the three obscure Belts, commonly seen in Jupiter, as in the rest of his Diske, and having also observed Spots in the midst of that Planet, and sometimes Brightnesses, such as have bin formerly seen in the Sun, hath at length discover'd a Permanent Spot in the Northern part of the most Southern Belt; by the means whereof, he hath concluded, that Jupiter turns about his Axis in 9. hours, 56. minutes, and makes 29. whole circumvolutions in 12 dayes 4. minutes of ours, and 360 in 149. dayes. For he has found, that this Spot was not caused by the Shadow of any Satellit, as well by reason of its Situation, as because it appeared, when there could be no Shadow. Besides, that its motion differed from that of the Shadows, which is almost equal, as well towards the Edges as towards the Middle of Jupiter: Whereas, on the contrary, this Spot hath all the accidents, that must happen to a thing, which is upon the surface of a round Body moving; for example, to move much more slowly towards the Edges, than towards the Middle, and to pass over that part, which is in the middle of the Diske, equal to the half of the Diameter, in the sixth part of the time, it takes to make the whole revolution: he having seen this half pass'd over, in 99 or 100 minutes just, as it must happen, supposing the whole circumrotation is made in 9. hours 56. minutes.

He hath not yet been able to determine the Situation of the Axis, upon which this motion is made, because the Belts, according to which it is made, have for some years appeared streight, though in the precedent years, other Astronomers have seen them a little crooked: Which sheweth, that the Axis of the diurnal motion of Jupiter is a little inclined to the plain of the Ecliptick. But in time we may discover, what certainty there is in this matter.

[Sidenote: These Tables are not yet sent over, but, 'tis hoped, will be, ere long.]

After this excellent Discovery, he hath calculated many Tables, whereof he gives the Explication and Use in the Letters by him addressed to the Abbot Falconieri. By the means of them, one may know, when this Spot may be seen by us. For, having first {173} considered it in relation to the Sun, in respect whereof, its motion is regular, he considers the same in relation to the Earth, where We observe it; and shews by the means of his Tables, what is to be added or subtracted, to know, at what time the said Spot is to come into the middle of Jupiter's Diske, according as he is Oriental or Occidental. He hath also considered it in relation to an unmovable point, which he has supposed to be the first point of Aries, because we thither refer here upon Earth the beginning of all the Celestial motions, and there is the Primum mobile, that one would imagine, if we were in Jupiter, as we do here imagine Ours of 24. hours.

The Discovery is one of the best, that have been yet made in the Heavens; and those, that hold the Motion of the earth, find in it a full Analogy. For, Jupiter turning about the Sun, does nevertheless turn about his Axis; and although he be much bigger than the Earth, he does nevertheless turn much more swiftly than it, since he makes more than two Turns, and a third part, for its one; and carries with him 4. Moons, as the Earth does one.

This Observation ought to excite all Curious persons to endeavour the perfecting of Optick Glasses, to the end that it may be discovered, whether the other Planets, as Mars, Venus and Mercury, about whom no Moon hath as yet been discovered, do yet turn about their Axes, and in how much time they do so; especially Mars, in whom some Spot is discover'd, and Venus, wherein M.Burattini hath signified from Poland, he has observ'd Inequalities, as in the Moon.

It will be worth while, to watch for the seeing of Jupiter again this Spring, that this happy Observation may be confirmed in divers places, and endeavours used to make new ones.

* * * * *

An Account of some Books, lately published.

I. Hydrostatical Paradoxes, made out by New Experiments (for the most part Physical, and Easie) by the Honourable Robert Boyle. This Treatise, promised in Numb. 8. of these Papers, is now come forth: And was occasioned by the perusal of the Learned Monsieur Paschalls Tract, Of the AEquilibrium of Liquors, and of the Weight of the Air: Of which two Subjects, the latter having been more clearly made out in England by Experiments, which could not be made by Monsieur Paschal and others, that wanted the advantage of such Engines and Instruments, as have here been frequently made use {174} off; Our Noble Author insists most upon giving us his thoughts of the former, videl. the AEquilibrium of Liquors: Which Discourse consisting partly of Conclusions, and partly of Experiments, the former seem to Him to be almost all of them consonant to the Principles and Laws of the Hydrostaticks; but as for the latter, the Experimental proofs, offered by M. Paschall for his Opinions, are by our Author esteemed such, that he confesses, he hath no mind to make use of them: for which he alledges more reasons than one; which, doubtless, will appear very satisfactory to Intelligent Readers.

Wherefore, instead of the those Paschalian Experiments, there is in this Treatise deliver'd a far more Expeditious way, to make out, not only most of the Conclusions, agreed on these two Authors, but others also, that M Paschall mentions not: and that with so much more ease and clearness, that persons, but ordinarily versed in the common principles of Hydrostaticks, may readily apprehend, what is deliver'd, if they will but bring with them a due Attention, and Minds disposed to prefer Reason and Experience to Vulgar opinions and Authors.

It not being our Authors present Task, to deliver a Body of Hydrostaticks, but only some Paradoxes, which he conceives to be proveable by his New way of making them out, he delivers them in as many distinct Propositions; after each of which, he endeavours, in a Proof, or an Explication, to show, both that it is true, and why it ought to be so.

The Paradoxes themselves (after a premised Postulatum) are these:

1. That in Water, and other Fluids, the Lower parts are pressed by the Upper.

2. That a lighter Fluid may gravitate or weigh upon a heavier.

3. That, if a Body, contiguous to the Water, be altogether, or in part, lower than the highest level of the said Water, the lower part of the Body will be pressed upward by the Water, that touches it beneath.

4. That in the Ascension of Water in Pumps, &c. there needs nothing to raise the Water, but a Competent weight of an External Fluid.

5. That the pressure of an External Fluid is able to keep an Heterogeneous Liquor suspended at the same height in several Pipes, though these Pipes be of very different Diameters.

{175}

6. If a Body be placed under Water, with its uppermost Surface parallel to the Horizon; how much Water soever there may be on this or that side above the Body, the direct pressure susteined by the Body (for we now consider not the Lateral nor the Recoyling pressure, to which the Body may be exposed, if quite environed with Water) is no more, than that of a Column of water, having Horizontal Superficies of the Body for its Basis, and the Perpendicular depth of the Water for its height.

And so likewise,

If the Water, that leans upon the Body, be contained in Pipes open at both ends, the pressure of the Water is to be estimated by the weight of a pillar of Water, whose Basis is equal to the lower Orifice of the Pipe (which we suppose to be parallel to the Horizon) and its height equal to a perpendicular, reaching thence to the top of the Water; though the Pipe be much inclined towards the Horizon, or though it be irregularly shap'd, and much broader in some parts, than the said Orifice.

7. That a Body, immersed in a Fluid, sustains a Lateral pressure from the Fluid; and that increased, as the depth of the immersed Body, beneath the Surface of the Fluid, increaseth.

8. That Water may be made as well to depress a Body lighter than it self, as to buoy it up.

9. That, whatever is said of Positive Levity, a parcel of Oyl lighter than Water, may be kept in Water without ascending in it.

10. That the cause of the Ascension of Water in Syphons, and of its flowing through them, may be explicated without having a recourse to Nature's abhorrency of a Vacuum.

11. That a Solid Body, as ponderous as any yet known, though near the Top of the water it will sink by its own weight; yet if it be placed at a greater depth, than that of twenty times its own thickness; it will not sink, if its descent be not assisted by the weight of the incumbent Water.

These are the Paradoxes, evinced by our Authour with much evidence and exactness, and very likely to invite Ingenious men to cultivate and to make further disquisitions in so excellent a part of Philosophy, as are the Hydrostaticks; and Art deserving great Elogiums, not only, upon the account of the Theorems and Problems, which are most of them pure and handsome productions of Reason, very delightful and divers of them surprising, and besides, much conducing to the clear explication and {176} thorow-understanding of many both familiar and abstruse Phaenomena of Nature; but also, upon the score of its Practical use, since the Propositions, it teaches, may be of great importance to Navigation, and to those that inquire into the Magnitudes and Gravities of Bodies, as also to them, that deal in Salt-works: Besides, that the Hydrostaticks may be made divers waies serviceable to Chymists, as the Author intimates, and intends to make manifest, upon several occasions, in his yet unpublisht part of the Usefulness of Natural and Experimental Philosophy.

These Propositions are shut up by two important Appendixes, whereof the one contains an Answer to seven Objections by a late learned Writer, to evince, that the upper parts of water press not upon the lower; the other, solves that difficult problem, why Urinators or Divers, and others, who descend to the bottom of the Sea, are not oppressed with the weight of the incumbent water? where, among other solutions, that is examined, which occurs in a printed Letter of Monsieur des Cartes, but is found unsatisfactory.

II. Nicolai Stenonis de Musculis & Glandulis Observationum Specimen; cum duabus Epistolis Anatomicis. In the Specimen it self, the Author, having described in general, both the Structure and the Function of the Muscles, applies that description to the Heart, to demonstrate that that is also a true Muscle: Observing first, that in the substance of the Heart there appears nothing but Arteries, Veins, Nerves, Fibres, Membrans; and that that, & nothing else is found in a Muscle; affirming withall, that which is commonly taught of the Muscles, and particularly of the Heart's Parenchyma, as distinct from Fibres, is due, not to the Senses, but the Wit of Anatomists: so that he will not have the Heart made up of a substance peculiar to it self, nor considered as the principle of Innate heat, or of Sanguification, or of vital spirits. He observes next, that the Heart performs the like operation with the Muscles, to wit, to contract the Flesh; which action how it can have a different cause from that of the Contraction made in the Muscles, where there is so great a parity and agreement in the Vessels, he sees not. And as for the Phaenomena, that occur, of the Motion of the Heart, he undertakes to explicate them all, from the Ductus or Position of the Fibres; but refers for the performance of this undertaking to another Treatise, he intends to publish.

[Sidenote: _Conglobate_ Glanduls are called those, that do consist, as it were, of one continued substance, having an _even_ superficies; whereof there are many in the _Mesentery_, and in other places: contra distinguisht to those, that bear the name of _Conglomerate_ Glanduls, which are made up of several small Kernels, such as the _Pancreas_, the _Salivating Glanduls_, &c._]

As to his Observations about Glanduls, he affirms, that he has been the First, that has discover'd that Vessel, which by him is call'd {177} Salivare Exterius, passing from the Parotides (or the two chief Arteries that are on the right and left side neer the Throat) into the Mouth, and conveying the Spittle: Where he also gives an account of several other Vessels and Glanduls, some about the Lips; others under the Tongue; others in the Pallate &c. To which he adds the Vessels of the Eye-lids, which have their root in the Glanduls that are about the Eyes, and serve for the shedding of Tears. He mentions also several things about the Lymphatick vessels, and is of opinion, that the knowledge thereof may be much illustrated by that kind of Glanduls that are called Conglobatae, and by their true insertion into the veins; the mistake of the latter whereof, he conceives to have very much misled the Noble Ludovicus de Bills, notwithstanding his excellent method of dissection. And here he observes first, that all the Lymphatick vessels have such a commerce with the Glanduls, that none of them is found in the body, which either has not its origine from, or is inserted into a Glandule: And then, that Glanduls are a kind of Strainers, so form'd, that whilst the Blood passes out of the Arteries into the Veins through the small Capillary vessels, the Serous parts thereof, being freed from the Sanguineous, are by vertue of the beat expell'd through fit pores into the Capilaries of the Lymphaticks, the direction of the Nerves concurring.

Of the two annex'd Epistles, the First gives an account of the dissection of two Raja's or Skates, and relates that the Author found in the bellies of these Fishes a Haddock of 11/2 span long, and a Sole, a Plaise, and nine middle-sized Sea crafishes; whereof not only the three former had their flesh, in the fishes stomack, turn'd into a fluid, and the Gristles or Bones into a soft substance, but the Crafishes had their shels comminuted into very small particles, tinging here and there the Chyle near the Pylorus; which he judges to be done not so much by the heat of the Fishes stomack, as by the help of some digesting juyce. Coming to the Uterus of these Fishes, he takes occasion to examine, with what ground several famous Naturalists and Anatomists have affirm'd, that Eggs are the uterus exposed or ejected out of the body of the Animal. Taking a view of their Heart, he there finds but one ventricle, and discourses of the difficulty arising from thence. As for the Lungs, he saw no clearer footsteps of them in these, than he had done in other Fishes: but within the mouth he trac'd several gaping fissures, and found the recesses of the Gills so form'd, that the water taken in at the mouth, being let out by these dores, cannot by them re-enter, by reason of a skin outwardly passing over every hole, and covering it. Where he intimates, that though Fishes have not true Lungs, yet they want not a Succedaneum thereto, to wit, the Gills; and if water may be to Fishes, what Air is to terrestrial Animals, for Respiration: affecting, that whereas nothing is so necessary for the conservation of Animal life as a reciprocal Access and Recess of the Ambient to the sanguineous vessels, tis all one, whether that be done by receiving the Ambient within the body, or by its gentle passing by the Prominent vessels of the Gills.

The other Epistle, contains some Ingenious Observations, touching the way, by which the Chicken, yet in the shell, is nourish't, videl. not by the conveyance of the Yolk into the Liver by the Umbilical vessels, nor into the Stomack by the {178} Mouth, but by a Peculiar ductus, by him described, into the Intestins, where, according to his alledged experience, it is turn'd into Chyle: which he affirms, he hath discover'd, by taking an Egge from under a brooding Hen, when the Chicken was ready to break forth, and when he was looking for the passage of the Yolk, out of its integument into the Liver, by finding it pass thence into the Intestins, as he found the White to do by the mouth into the belly. Whence he inclines to infer, that, since every faetus takes in at the mouth the liquor it swims in, and since the Chicken receives the white of the Egge into the mouth, and the yolk by the new discover'd ductus into the Intestins, it cannot be certainly made out, that a part of the Chyle is conveyed into the Liver, before it passes into the Heart; Exhorting in the mean time the Patrons of the Liver, that they would produce Experiments to evince their Ratiocinations.

III. Regneri de Graeff, de Succi Pancreatici Natura & usu, Exercitatio Anatomico-medica. In this Tract, the Industrious Author, after he has enumerated the various opinions of Anatomists concerning the use of that kernelly substance; call'd Pancreas (in English, the Sweetbred) endeavours to prove experimentally that this Glandule was not form'd by Nature, to separate any Excrementitious humor, and to convey it into the Intestins, but to prepare an useful juyce out of the Blood and Animal Spirits, of a somewhat Acid taste, and to carry the same into the Gut, call'd Duodenum, to be there mixt with the Aliment, that has been in some degree already fermented in the Stomack, for a further fermentation, to be produced by the conflux of the said acid Pancreatick juyce and some Bilious matter, abounding with volatile Salt, causing an Effervescence; which done, that juyce is, together with the purer part of the nourishment, carried into the Milkie veins, thence into the common receptacle of the Chyle and Lymphatick liquor, and so through the ductus Thoracicus into the right Ventricle of the Heart.

This Assertion, first advanced (saith the Author) partly by Gothofredus Mobius, partly by Franciscus de le Boe Sylvius, he undertakes to prove by experiments; which, indeed, he has with much industry, tried upon several Animals, to the end that he might collect some of this juyce of the Pancreas for a taste: which having at last obtained, and found it somewhat acid, he thereupon proceeds to deliver his opinion both of the constitution and quantity of this Succus in healthy Animals, and the vices thereof, in the unhealthy: deriving most diseases partly from its too great Acidity, or from its saltness, or harshness; partly from its paucity or redundancy: but especially, endeavouring to reduce from thence, as all intermittent Feavers (of all the Phaenomena whereof he ventures to assign the causes from this Hypothesis) so also the Gout, Syncope's, Stranguries, Oppilations, Diarrhaeas, Dysenteries, Hysterical and Colick passions, &c. All which he concludes with mentioning the waies and remedies to cure the manifold peccancy of this juyce by Evacuations and Alterations.

This seeming to be a new as well as a considerable discovery, it is hop'd, that others will by this intimation be invited to prosecute the same by further experiments, either to confirm what this Author has started, if true, or to rectifie it, if he be mistaken.

* * * * *

NOTE.

In Fig. 1. of Num. 9 of these Tracts the Graver hath placed the bended end of the Springing Wire C F, above the Wire-staple B, between it and the Ring E, of the Weight D; whereas that end should have been so expressed, as to pass under the Wire-staple, betwixt its two Wires, into the said Ring.

* * * * *

London, Printed for John Martyn, and James Allestry, Printers to the Royal Society. 1666.

{179}

* * * * *



Num. 11.

PHILOSOPHICAL TRANSACTIONS.

* * * * *

Munday, April. 2. 1666.

* * * * *

The Contents.

A Confirmation of the former Account, touching the late Earth-quake near Oxford, and the Concomitants thereof, by Mr. Boyle. Some Observations and Directions about the Barometer, communicated by the same Hand. General Heads for a Natural History of a Country, small or great, proposed by the same. An Extract of a Letter, written from Holland, about Preserving Ships from being Worm-eaten. An Account of Mr. Boyle's lately publish't Tract, entituled, The Origine of Forms and Qualities, illustrated by Considerations and Experiments.

* * * * *

A Confirmation of the former Account touching the late Earth-quake near Oxford, and the Concomitants thereof.

This Confirmation came from the Noble Mr. Boyle in a Letter, to the Publisher, as followeth:

[Sidenote: * See Num. 10. Phil. Transactions p. 166-171; at the time of the printing whereof, this Relation of Mr. Boyle was not yet come to hand.]

As to the Earth-quake, your curiosity about it makes me sorry, that, though I think, I was the first, that gave notice of it to several of the Virtuosi at Oxford; yet the Account, that I can send you about it, is not so much of the Thing it self, {180} as of the Changes of the Air, that accompanied it. To inform you of which, I must relate to you, that riding one Evening somewhat late betwixt Oxford & a Lodging, I have at a place, 4 miles distant from it, the weather having been for a pretty while Frosty, I found the Wind so very cold, that it reduced me to put on some defensives against it, which I never since, nor, if I forget not, all the foregoing part of the Winter was obliged to make use off. My unwillingness to stay long in so troublesome a Cold, which continued very piercing, till I had got half way home-ward, did put me upon galloping at no very lasy rate; and yet, before I could get to my Lodgings, I found the Wind turned, and felt the Rain falling; which, considering the shortness of the time, and that this Accident was preceded by a setled Frost, was surprising to me, and induced me to mention it at my return, as one of the greatest and suddainest Alterations of Air, I have ever observ'd: And what changes I found, have been taken notice of in the Gravity of the Atmosphere at the same time by that Accurate Observer * Dr. Wallis, who then suspected nothing of what follow'd; as I suppose, he has ere this told you himself. Soon after, by my guess about an hour, there was a manifest Trembling in the House where I was (which stands high in comparison of Oxford.) But it was not there so great, but that I, who chanced to have my thoughts busied enough on other matters, than the weather, should not have taken notice of it as an Earth-quake, but have imputed it to some other cause, if one, that you know, whose hand is employed in this Paper, and begins to be a diligent observer of Natural things, had not advertis'd me of it; as being taken notice of by him and the rest of the people of the House. And soon after there hapned a brisk Storm: whereupon I sent to make inquiry at a place call'd Brill, which standing upon a much higher ground, I supposed might be more obnoxious to the effects of the Earth-quake (of which, had I had any suspition of it, my having formerly been in one neer the Lacus Lemanus, would have made me the more observant:) But the person I sent to, being {181} disabled by sickness to come over to me (which he promis'd to do, as soon as he could) writ me only a Ticket, whose substance was, That the Earth-quake was there much more considerable, than where I lodged, and that at a Gentlemans house, whom he names (the most noted Person, it seems, of the neighbourhood) the House trembled very much, so as to make the Stones manifestly to move to and fro in the Parlour, to the great amazement and fright of all the Family. The Hill, whereon this Brill stands, I have observ'd to be very well stor'd with Mineral substances of several kinds; and from thence I have been inform'd by others, that this Earth-quake reach'd a good many miles; but I have neither leasure, nor inclination to entertain you with uncertain reports of the Extent and other Circumstances, especially since a little further time an inquiry may enable me to give you a better warranted account.

* * * * *

Some Observations and Directions about the Barometer, communicated by the same Hand, to the Author of this Tract.

These shall be set down, as they came to hand in another Letter; videl.

[Sidenote: * See Num. 9. of the Phil. Transact. p. 159 the last paragraph.]

As to the Barometrical Observations (as for brevities sake I use to call them) though you * guessed aright, that, when I saw those of the Learned and Inquisitive Dr. Beale, I had not Mine by me, (for I left them, some years since, in the hands of a Virtuoso, nor have I now the leasure to look after those Papers;) yet since by the Communication, you have made publick, 'tis probable, that divers Ingenious men will be invited to attempt the like Observations, I shall (notwithstanding my present haste) mention to you some particulars, which perhaps will not appear unseasonable, that came into my mind upon the reading of what you have presented the Curious.

[Sidenote: * Some whereof have been since invited by the Publisher, to give their concurrence herein.]

When I did, as you may remember, some years agoe, publickly express and desire that some Inquisitive men would {182} make Baroscopical Observations in several parts of England (if not in forrain Countries * also;) and to assist them, to do so, presented some of my Friends with the necessary Instruments: The declared reason of my desiring this Correspondence was (among other things) that by comparing Notes, the Extent of the Atmospherical Changes, in point of Weight, might be the better estimated. But not having hitherto received some account, that I hoped for, I shall now, without staying for them, intimate thus much to you: That it will be very convenient, that the Observers take notice not only of the day, but as near as they can, of the Houre wherein the height of the Mercurial Cylinder is observ'd: For I have often found, that within less than the compass of one day, or perhaps half a day, the Altitude of it has so considerably vary'd, as to make it in many cases difficult, to conclude any thing certainly from Observations, that agree but in the day.

It will be requisite also, that the Observers give notice of the Scituation of the place, where their Barometers stand, not only, because it will assist men to Judge, whether the Instruments were duely perfected, but principally, because, that though the Baroscope be good (nay, because it is so) the Observations will much disagree, even when the Atmosphere is in the same state, as to Weight, if one of the Instruments stand in a considerably higher part of the Countrey, than the other.

To confirm both the foregoing admonitions, I must now inform you, that, having in these parts two Lodgings, the one at Oxford, which you know stands in a bottom by the Thames side, and the other at a place four miles thence, seated upon a moderate Hill, I found, by comparing two Baroscopes, that I made, the one at Oxford, the other at Stanton St. Johns, that, though the former be very good, and have been noted for such, during some years, and the latter was very carefully fill'd; yet by reason, that in the Higher place, the incumbent part of the Atmosphere must be lighter, than in the Lower, there is almost {183} always between 2 and 3 Eights of an Inch difference betwixt them: And having sometimes order'd my servants to take notice of the Disparity, and divers times carefully observ'd it my self, when I pass'd to and fro between Oxford and Stanton, I generally found, that the Oxford Barometer and the other, did, as it were by common consent, rise and fall together so, as that in the former the Mercury was usually 3/8 higher, than in the latter.

Which Observations may teach us, that the Subterraneous steams, which ascend into the Air, or the other Causes of the varying Weight of the Atmosphere, do, many times, and at least in some places, uniformly enough affect the Air to a greater height, than, till I had made this tryall, I durst conclude.

But, as most of the Barometricall observations are subject to exception, so I found the formerly mentioned to be. For (to omit lesser variations) riding one evening from Oxford to Stanton, and having, before I took horse, look't on the Baroscope in the former of these 2. places, I was somewhat surprised, to find at my comming to the latter, that in places no farther distant, and notwithstanding the shortness of the time (which was but an hour and a half, if so much) the Barometer at Stanton was short of its usual distance from the other, near a quarter of an Inch, though, the weather being fair and calm, there appear'd nothing of manifest change in the Air, to which I could adscribe so great a Variation; and though also, since that time, the Mercury in the two Instruments hath, for the most part, proceeded to rise and fall as before.

And these being the only Observations, I have yet met with, wherein Baroscopes, at some Distance of Place, and Difference of Height, have been compar'd (though I cannot now send you the Reflexions, I have else where made upon them;) as the opportunity I had to make them my self, rendred them not unpleasant to me, so perhaps the Novelty will keep them from being unwelcome to you. And I confess, I have had some flying suspicions, that the odd Phaenomena of the Baroscope, which have hitherto more pos'd, than instructed us, may in time, if a {184} competent number of Correspondents do diligently prosecute the Inquiries (especially with Baroscopes, accommodated with Mr. Hooks ingenious additions) make men some Luciferous discoveries, that possibly we do not yet dream off.