Chapter II: Front Matter (2)

They use exceeding great quantity of Wood, in making and repairing the Engins, and in the Furnaces (whereof there are 16. each of them carrying 24. Retorts;) but principally in the Mines, which need continual reparation, the Fir-trees lasting but a small time under ground. They convey their Wood thus: About four miles from the Mines, on the sides of two mountains, they cut down the Trees, and draw them into the interjacent Valley, higher in the same Valley, so that the Trees, according to the descent of the water lye betwixt it and _Idria_: with vast charges and quantities of Wood they made a Lock or Dam, that suffers not any water to pass; they expect afterwards till there be water enough to float these Trees to _Idria_; for, if there be not a spring, (as generally there is,) Rain, or the melting of the Snow, in a short time, afford so much water, as is ready to run over the Dam, and which (the Flood-gates being open'd) carries all the Trees impetuously to _Idria_, where the Bridge is built very strong, and at very oblique Angles to the stream, on purpose to stop them, and throw them on shore neer the Mines. {25}

Those Mines cost the _Emperour_ heretofore 70000. or 80000. _Florens_ yearly, and yielded less _Mercury_ than at present, although it costs him but 28000. _Florens_ now. You may see what his Imperial Majesty gets by the following account, of what _Mercury_ the Mines of _Idria_ have produced these last three years.

1661. l.
Ordinary _Mercury_ 198481
Virgin _Mercury_ 6194
--------
204675
--------

1662. l.
Ordinary _Mercury_ 225066
Virgin _Mercury_ 9612
--------
234678
--------

1663. l.
Ordinary _Mercury_ 244119
Virgin _Mercury_ 11862
--------
255981
--------

There are alwaies at work 280 persons, according to the relation I received from a very civil person, who informed me also of all the other particulars above mentioned, whose name is _Achatio Kappenjagger_; his Office, _Contra-scrivano per sua Maestà Cesarea in Idria del Mercurio_.

To give some light to this Narrative, take this Diagramme: F. is the water, C. B. a vessel, into which it runs. DG. EH. FI. are streams perpetually issuing from that vessel; D. E. F. three sives, the distance of whose wires at bottom lessen proportionably. G. the place, wherein the Earth, that pass'd through the sive D. is retained; from whence 'tis taken by the second man; and what passes through the sive E. is retained in H. and so of the rest. K. L. M. wast water, which is so much impregnated with _Mercury_, that it cureth Itches and sordid Ulcers. See Fig. 1.

I will trespass a little more upon you, in describing the contrivance of blowing the Fire in the _Brassworks_ of _Tivoli_ neer _Rome_ (it being new to me) where the Water blows the Fire, not by moving the Bellows, (which is common) but by affording the Wind. See Fig. II. Where A. is the {26} River, B. the Fall of it, C. the Tub into which it falls, LG. a Pipe, G. the orifice of the Pipe, or Nose of the Bellows, GK. the Hearth, E. a hole in the Pipe, F. a stopper to that hole, D. a place under ground, by which the water runs away. Stopping the hole E, there is a perpetual strong wind, issuing forth at G: and G. being stopt, the wind comes out so vehemently at E, that it will, I believe, make a Ball play, like that at _Frescati_.

* * * * *

_An Extract of a Letter, containing some Observations, made in the ordering of _Silk-worms_, communicated by that known _Vertuoso_, Mr. _Dudley Palmer_, from the ingenuous Mr. _Edward Digges_._

I herewith offer to your _Society_ a small parcel of my _Virginian_ Silk. What I have observed in the ordering of Silk-worms, contrary to the received opinion, is:

1. That I have kept leaves 24. hours after they are gathered, and flung water upon them to keep them from withering; yet when (without wiping the leaves) I fed the worms, I observed, they did as well as those fresh gathered.

2. I never observed, that the smell of _Tobacco_, or smels that are rank, did any waies annoy the worm.

3. Our country of _Virginia_ is very much subject to Thunders: and it hath thundered exceedingly when I have had worms of all sorts, some newly hatched; some half way in their feeding; others spinning their Silk; yet I found none of them concern'd in the Thunder, but kept to their business, as if there had been no such thing.

4. I have made many bottoms of the Brooms (wherein hundreds of worms spun) of _Holly_; and the prickles were so far from hurting them, that even from those prickles they first began to make their bottoms.

I did hope with this to have given you assurance, that by retarding the hatching of seed, two crops of silk or more {27} might be made in a Summer: but my servants have been remiss in what was ordered, I must crave your patience till next year.

* * * * *

_An account of _Micrographia_, or the _Physiological Descriptions_ of _Minute Bodies_, made by _Magnifying Glasses_._

The Ingenious and knowing Author of this _Treatise_, Mr. _Robert Hook_, considering with himself, of what importance a faithful _History of Nature_ is to the establishing of a solid Systeme of _Natural Philosophy_, and what advantage _Experimental_ and _Mechanical_ knowledge hath over the Philosophy of _discourse_ and _disputation_, and making it, upon that account, his constant business to bring into that vast Treasury what portion he can, hath lately published a Specimen of his abilities in this kind of study, which certainly is very welcome to the Learned and Inquisitive world, both for the _New discoveries_ in _Nature_, and the _New Inventions_ of _Art_.

As to the _former_, the Attentive Reader of this Book will find, that there being hardly any thing so small, as by the help of _Microscopes_, to escape our enquiry, a new visible world is discovered by this means, and the Earth shews quite a new thing to us, so that in every _little particle_ of its matter, we may now behold almost as great a variety of creatures, as we were able before to reckon up in the whole _Universe_ it self. Here our Author maketh it not improbable, but that, by these helps the subtilty of the composition of Bodies, the structure of their parts, the various texture of their matter, the instruments and manner of their inward motions, and all the other appearances of things, may be more fully discovered; whence may emerge many admirable advantages towards the enlargement of the _Active_ and _Mechanick_ part of knowledge, because we may perhaps be enabled to discern the secret {28} workings of _Nature_, almost in the same manner, as we do those that are the productions of _Art_, and are managed by _Wheels_, and _Engines_, and _Springs_, that were devised by Humane wit. To this end, he hath made a very curious _Survey_ of all kinds of bodies, beginning with the _Point of a Needle_, and proceeding to the _Microscopical_ view of the _Edges_ of _Rasors, Fine Lawn, Tabby, Watered Silks, Glass-canes, Glass-drops, Fiery Sparks, Fantastical Colours, Metalline Colours, the Figures of Sand, Gravel in Urine, Diamonds in Flints, Frozen Figures, the Kettering Stone, Charcoal, Wood and other Bodies petrified, the Pores of Cork, and of other substances, Vegetables growing on blighted Leaves, Blew mould and Mushromes, Sponges, and other Fibrous Bodies, Sea-weed, the Surfaces of some Leaves, the stinging points of a Nettle, Cowage, the Beard of a wild Oate, the seed of the Corn-violet, as also of Tyme, Poppy and Purslane._ He continues to describe _Hair, the scales of a Soal, the sting of a Bee, Feathers_ in general, and in particular those of _Peacocks; the feet of Flies; and other Insects; the Wings and Head of a Fly; the Teeth of a Snail; the Eggs of Silk-worms; the Blue Fly; a water Insect; the Tufted Gnat; a White Moth; the Shepheards-spider; the Hunting Spider, the Ant; the wandring Mite; the Crab-like insect, the Book-worm, the Flea, the Louse, Mites, Vine mites._ He concludeth with taking occasion to discourse of two or three very considerable subjects, viz. _The inflexion of the Rays of Lights in the Air; the Fixt stars; the Moon._

In representing these particulars to the Readers view, the Author hath not only given proof of his singular skil in delineating all sorts of Bodies (he having drawn all the _Schemes_ of these 60 _Microscopical_ objects with his own hand) and of his extraordinary care of having them so curiously engraven by the Masters of that Art; but he hath also suggested in the several reflexions, made upon these Objects, such conjectures, as are likely to excite and quicken the Philosophical heads to very noble contemplations. Here are found inquiries concerning the _Propagation of Light_ through {29} differing mediums; concerning _Gravity_, concerning the _Roundness_ of Fruits, stones, and divers artificial bodies; concerning _Springiness_ and _Tenacity_; concerning the _Original_ of _Fountains_; concerning the _dissolution of Bodies into Liquors_; concerning _Filtration_, and the ascent of Juices in Vegetables, and the use of their _Pores_. Here an attempt is made of solving the strange _Phænomena_ of _Glass-drops_; experiments are alleged to prove the _Expansion_ of _Glass_ by heat, and the _Contraction_ of _heated-Glass_ upon cooling; _Des Cartes_ his _Hypothesis of Colours_ is examined: the _cause of Colours_, most likely to the Author, is explained: Reasons are produced, that _Reflection_ is not necessary to produce _colours_, nor a _double refraction_: some considerable _Hypotheses_ are _offered_, for the explication of Light by Motion; for the producing of all colours by Refraction; for reducing all sorts of colours to two only, _Yellow_ and _Blew_; for making the _Air_, a dissolvent of all _Combustible Bodies_: and for the explicating of all the regular figures of _Salt_, where he alleges many notable instances of the _Mathematicks_ of _Nature_, as having even in those things which we account vile, rude & course, shewed abundance of curiosity and excellent _Geometry_ and _Mechanism_. And here he opens a large field for inquiries, and proposeth Models for prosecuting them, 1. By making a full collection of all the differing kinds of _Geometricall_ figur'd bodies; 2. By getting with them an exact History of their places where they are generated or found: 3. By making store of Tryals in Dissolutions and Coagulations of several Crystallizing Salts: 4. By making trials on metalls, Minerals and Stones, by dissolving them in severall _Menstruums_, and Crystallizing them, to see what Figures will arise from those several compositums: 5. By compounding & coagulating several Salts together into the same mass, to observe the Figure of that product: 6. By inquiring the closenes or rarity of the texture of those bodys by examining their gravity, and their refraction, &c. 7. By examining what operations the fire hath upon several kinds of Salts, what changes it causes in their figures, Textures, or {30} Vertues. 8. By examining their manner of dissolution, or acting upon those bodies dissoluble in them and the Texture of those bodies before and after the process. 9. By considering, by what and how many means, such and such figures, actions and effects could be produced, and which of them might be the most likely, &c.

He goes on to offer his thoughts about the Pores of bodies, and a _kind_ of _Valves_ in wood; about spontaneous generation arising from the Putrefaction of bodies; about the nature of the Vegetation of mold, mushromes, moss, spunges; to the last of which he scarce finds any Body like it in texture. He adds, from the naturall contrivance, that is found in the leaf of a Nettle, how the stinging pain is created, and thence takes occasion to discourse of the poysoning of Darts. He subjoyns a curious description of the shape, _Mechanism_ and use of the _sting_ of a _Bee_; and shews the admirable Providence of Nature in the contrivance and fabrick of _Feathers_ for Flying. He delivers those particulars about the Figure, parts and use of the head, feet, and wings of a Fly, that are not common. He observes the various wayes of the generations of Insects, and discourses handsomely of the means, by which they seem to act so prudently. He taketh notice of the _Mechanical_ reason of the _Spider's_ Fabrick, and maketh pretty Observations on the hunting Spider, and other Spiders and their Webs. And what he notes of a Flea, Louse, Mites, and Vinegar-worms, cannot but exceedingly please the curious Reader.

Having dispatched these Matters, the Author offers his Thoughts for the explicating of many _Phænomena_ of the Air, from the _Inflexion_, or from a _Multiplicate Refraction_ of the rays of Light within the Body of the _Atmosphere_, and not from a _Refraction_ caused by any terminating _superficies_ of the Air above, nor from any such exactly defin'd _superficies_ within the body of the _Atmosphere_; which conclusion he grounds upon this, that a _medium_, whose parts are unequally _dense_, and mov'd by various motions and transpositions as to one another, will produce all these {31} visible effects upon the rays of Light, without any other _coefficient_ cause: and then, that there is in the Air or _Atmosphere, such_ a variety in the constituent parts of it, both as to their _density_ and _rarity_, and as to their divers mutations and positions one to another.

He concludeth with two _Celestial Observations_; whereof the _one_ imports, what multitudes of Stars are discoverable by the _Telescope_, and the variety of their magnitudes; intimating with all, that the longer the Glasses are, and the bigger apertures they will indure, the more fit they are for these discoveries: the _other_ affords a description of a _Vale_ in the _Moon_, compared with that of _Hevelius_ and _Ricciolo_; where the Reader will find several curious and pleasant Annotations, about the Pits of the _Moon_, and the Hills and Coverings of the same; as also about the variations in the _Moon_, and its _gravitating_ principle, together with the use, that may be made of this Instance of a gravity in the _Moon_.

As to the _Inventions of Art_, described in this Book, the curious Reader will there find these following:

1. A _Baroscope_, or an Instrument to shew all the Minute Variations in the _Pressure of the Air_; by which he affirms, that he finds, that before and during the time of rainy weather, the Pressure of the Air is less; and in dry weather, but especially when an _Easterly_ Wind (which having past over vast Tracts of Land, is heavy with earthy particles) blows, it is much more, though these changes be varied according to very odd Laws.

2. A _Hygroscope_, or an Instrument, whereby the _Watery steams_, volatile in the Air, are discerned, which the Nose it self is not able to find. Which is by him fully described in the Observation touching the _Beard of a wild Oate_, by the means whereof this Instrument is contrived.

3. An Instrument for _graduating Thermometers_, to make them _Standards_ of _Heat_ and _Cold_.

4. A _New Engine_ for _Grinding Optick Glasses_, by means of which he hopes, that any Spherical Glasses, of what length {32} soever, may be speedily made: which seems to him most easie, because, if it succeeds, with one and the same Tool may be ground an _Object Glass_ of any length or breadth requisite, and that with very little or no trouble in fitting the _Engine_, and without much skill in the _Grinder_. He thinks it very exact, because to the very last stroke the Glass does regulate and rectifie the _Tool_ to its exact Figure; and the longer or more the _Tool_ and _Glass_ are wrought together, the more exact will both of them be of the desired Figure. He affirms further, that the motions of the Glass and Tool do so cross each other, that there is not one point of eithers surface, but hath thousands of cross motions thwarting it, so that there can be no kind of _Rings_ or _Gutters_ made, either in the _Tool_ or _Glass_.

5. A _New Instrument_, by which the _Refraction_ of all kinds of Liquors may be exactly measured, thereby to give the Curious an opportunity of making Trials of that kind, to establish the _Laws_ of _Refraction_, to wit, whether the _Sines of the Angles of Refraction are respectively proportionable to the Sines of the Angles of Incidence:_ This Instrument being very proper to examine very accurately, and with little trouble, and in small quantities, the _Refraction_ of any Liquor, not only for _one_ inclination, but for _all_; whereby he is enabled to make accurate _Tables_. By the same also he affirms to have found it true, that what _proportion_ the _Sine_ of the Angle of the one _inclination_ has to the _Sine_ of its Angle of _Refraction_, correspondent to it, the same proportion have all the other _Sines_ of Inclination to their respective _Sines_ of _Refractions_.

Lastly, this Author despairs not that there may be found many Mechanical Inventions, to improve our Senses of _Hearing, Smelling, Tasting, Touching_, as well as we have improved that of _Seeing_ by _Optick Glasses_.

* * * * *

London, Printed with Licence for _John Martyn_, and _James Allestry_, Printers to the _Royal Society_.

{33}

* * * * *

_Numb._ 3.

PHILOSOPHICAL _TRANSACTIONS._

* * * * *

_Munday_, _May_ 8. 1665.

* * * * *

The Contents.

_Some Observations and Experiments upon _May-dew_. The Motion of the
_Second Comet_ predicted, by the same person, who predicted that of the
former. A Relation of the Advice, given by a _French_ Gentleman,
touching the Conjunction of the _Ocean_ and the _Mediterranean_. Of the
way of killing _Ratle-snakes_, used in _Virginia_. A Relation of
Persons kill'd with Subterraneous _Damps_. Of the _Mineral_ of _Liege_,
yielding both _Brimstone_, and _Vitriol_, and the way of extracting
them out of it, used at _Liege_. An Account of Mr. _Boyle's_
Experimental _History_ of_ Cold.

* * * * *

_Some Observations and Experiments upon _May-Dew_._

That ingenious and inquisitive Gentleman, Master _Thomas Henshaw_, having had occasion to make use of a great quantity of _May-dew_, did, by several casual Essayes on that Subject, make the following Observations and Tryals, and present them to the _Royal Society_. {34}

That _Dew_ newly gathered and filtred through a clean Linnen cloth, though it be not very clear, is of a yellowish Colour, somewhat approaching to that of Urine.

That having endevoured to putrefy it by putting several proportions into Glass bodies with blind heads, and setting them in several heats, as of dung, and gentle baths, he quite failed of his intention: for heat, though never so gentle, did rather clarify, and preserve it sweet, though continued for two moneths together, then cause any putrefaction or separation of parts.

That exposing of it to the Sun for a whole Summer in Glasses, that hold about two Gallons, with narrow mouths, that might be stopp'd with Cork, the only considerable alteration, he observed to be produced in it, was, that Store of green stuff (such as is seen in Summer in ditches and standing waters) floated on the top, and in some places, grew to the sides of the Glass.

That putting four or five Gallons of it into a half Tub, as they call it, of Wood, and straining a Canvas over it, to keep out Dust and Insects, and letting it stand in some shady room for three weeks or a month, it did of itself putrefy and stink exceedingly, and let fall to the bottom a black sediment like Mudd.

That, coming often to see, what Alterations appeared in the putrefaction, He observed, that at the beginning, within twenty four hours, a slimy film floated on the top of the water, which after a while falling to the bottom, there came another such film in its place.

That if _Dew_ were put into a long narrow Vessel of Glass, such as formerly were used for Receivers in distilling of _Aqua Fortis_, the slime would rise to that height, that He could take it off with a Spoon; and when he had put a pretty quantity of it into a drinking Glass, and that it had stood all night, and the water dreined from it, if He had turned it out of his hand, it would stand upright in figure of the Glass, in substance like boyled white Starch, though something more transparent, if his memory (_saith he_) fail him not.

That having once gotten a pretty quantity of this gelly, and put it into a Glass body and Blind-head, He set it into a gentle {35} Bath with an intention to have putrefied it, but after a few days He found, the head had not been well luted on, and that some moisture exhaling, the gelly was grown almost dry, and a large _Mushrom_ grown out of it within the Glass. It was of a loose watrish contexture, such an one, as he had seen growing out of rotten wood.

That having several Tubs with good quantity of _Dew_ in them, set to putrefy in the manner abovesaid, and comming to pour out of one of them to make use of it, He found in the water a great bunch, bigger than his fist, of those Insects commonly called _Hog-lice_ or _Millepedes_, tangled together by their long tailes, one of which came out of every one of their bodies, about the bigness of a Horsehair: The Insects did all live and move after they were taken out.

That emptying another Tub, whereon the Sun, it seems, had used sometimes to shine, and finding, upon the straining it through a clean linnen cloth, two or three spoonfulls of green stuff, though not so thick nor so green as that above mentioned, found in the Glasses _purposely_ exposed to the Sun, He put this green stuff in a Glass, and tyed a paper over it, and coming some dayes after to view it, He found the Glass almost filled with an innumerable Company of small Flyes, almost all wings, such as are usually seen in great Swarms in the Aire in Summer Evenings.

That setting about a Gallon of this _Dew_ (which, he saith, if he misremember not, had been first putrefied and strained) in an open Jarre-Glass with a wide mouth, and leaving it for many weeks standing in a South-window, on which the Sun lay very much, but the Casements were kept close shut; after some time coming to take account of his _Dew_, He found it very full of little Insects with great Heads and small tapering Bodies, somewhat resembling Tadpoles, but very much less. These, on his approach to the Glass, would sink down to the bottom, as it were to hide themselves, and upon his retreat wrigle themselves up to the top of the water again. Leaving it thus for some time longer, He afterwards found the room very full of Gnats, though the Door and Windows were kept shut. He adds, that He did not at first suspect, that those Gnats had any {36} relation to the _Dew_, but after finding the Gnats to be multiplied and the little watry Animals to be much lessened in quantity, and finding great numbers of their empty skins floating on the face of his _Dew_, He thought, he had just reason to perswade himself, the Gnats were by a second Birth produced of those little Animals.

That vapouring away great quantities of his putrefied _Dew_ in Glass Basons, and other Earthen glased Vessels, He did at last obtain, as he remembers, above two pound of _Grayish Earth_, which when he had washed with more of the same _Dew_ out of all his Basons into one, and vapoured to siccity, lay in leaves one above another, not unlike to some kind of brown Paper, but very friable.

That taking this Earth out, and after he had well ground it on a Marble, and given it a smart Fire, in a coated Retort of Glass, it soon melted and became a Cake in the bottom, when it was cold, and looked as if it had been Salt and Brimstone in a certain proportion melted together; but, as he remembers, was not at all inflamable. This ground again on a Marble, _he saith_, did turn Spring water of a reddish purple Colour.

That by often calcining and filtring this Earth, He did at last extract about two ounces of a fine small _white Salt_, which, looked on through a good _Microscope_, seemed to have Sides and Angles in the same number and figure, as _Rochpeeter_.

* * * * *

_The Motion of the _Second_ Comet predicted, by the same Gentleman, who predicted that of the _former_._

Monsieur _Auzout_, the same Person, that not long since communicated to the World his _Ephemerides_ touching the course of the former _Comet_, and recommended several Copies of them to the _Royal Society_, to compare their Observations with his Account, and thereby, either to verifie his Predictions, or to shew, wherein they differ, hath lately sent another _Ephemerides_ concerning the Motion of the Second _Comet_, to the same end, that invited him to send the other. {37}

In that Tract he observes, first in _General_, that this second _Comet_ is contrary to the precedent, almost in all particulars: seeing that the _former_ moved very swift, _this_, pretty slow; _that_ against the Order of the signs from East to West, _this_, following them, from West to East: _that_, from South to North, _this_, from North to South, as far as it hath been hitherto, that we hear off, observed: _that_, on the side opposite to the Sun, _this_, on the same side: _that_, having been in its _Perigee_ at the time of its Opposition, _this_, having been there, out of the time of its Conjunction: where he taketh also notice, that this _Comet_ differs in brightness from the other, as well in its Body, which is far more vivid and distinct, as in its _Train_, whose splendor is much greater, since it may be seen even with great _Telescopes_, which were useless in the former, by reason of its dimness. After this he descends to particulars, and informs us, that he began to observe this Comet _April_ the second, and continued for some days following, and that as soon as he had made three or four Observations, he resolved to try again an _Ephemerides_; but that, having no instruments exact enough, and the Comet being in a place, destitute of Stars, and subject to Refractions, he feared to venture too much upon Observations so neer one another, since in such matters a perfect exactness is necessary, and wished to see some precedent Observations to direct him: which having obtained, he thereby verified what he had begun, and resolved to carry on his intended _Ephemerides_, especially being urged by his Friends, and engaged by his former undertaking, that so it might not be thought a meer hazard, that made him hit in the former; as also, that he might try, whether his Method would succeed as well in slower, as in swifter Comets, and in those, that are neer the Sun; as in such as are opposite thereunto, to the end, that men might be advertised of the _determination_ of its use, if it could not serve but in certain particular Cases.

He relateth therefore, that he had finished this New _Ephemerides_ _April_ the sixth, and put it presently to the Press; in doing of which, he hopes, he hath not disobliged the Publick: seeing that, though we should loose the sight of this Star within a few days, by reason of its approach to the Sun, yet having found, {38} that it is always to rise before the Sun, and that we may again see it better, when it shall rise betimes, towards the end of _May_, and in the beginning of _June_, if the cleerness of the Day-break hinder us not; he thought it worth the while to try, whether the truth of this _Ephemerides_ could be proved.

He affirms then, that the _Line_ described by this Star resembles hitherto a _Great Circle_, as it is found in all other Comets in the midst of their Course. He finds the said Circle inclined to the _Ecliptick_ about 26. d. 30'. and the _Nodes_, where it cuts it, towards the beginning of _Gemini_ and _Sagittary_; that it declines from the _Equator_ about 26. _d_ and cuts it towards the 11. d. and consequently, that its greatest _Latitude_ hath been towards _Pisces_, where it must have been _March_ 24. and its greatest _Declination_, towards the 25 d. of the _Equator_, where it was to have been _April_ 11.

He puts it in its _Perigee_ _March_ 27. about three of the Clock in the Afternoon, when it was about the 15 degrees of _Pisces_, a little more _Westerly_ then _Marshab_, or the _Wing_ of _Pegasus_, and that it was to be in _Conjunction_ with the _Sun_, _April_ 9. Where yet he noteth, that according to another Calculation, the _Perigee_ was _March_ 27. more towards Night, so that the Comet advances a little more towards the _East_, and retards towards the _West_; which not being very sensible in the first days, differs more about the end, and in the beginning; which he leaves to Observation.

He calculateth, that the greatest Motion it could make in one day, hath been 4. d. and 8'. or 9'; in one hour, about 10'. and 25". so that its _Diurnal Motion_ is to its last distance from the Earth a little more than as 1. to 14. and its _Hourly Motion_, as 1. to 330.

He wonders, that it hath not been seen sooner; the first Observations that he hath seen, but made by others, being of _March_ 17. Whereas he finds, that it might have been seen since _January_, at least in the Months of _February_ and _March_, when it rose at 2 of the Clock and before: because it is very likely, that, considering its bigness and brightness, when it was towards its _Perigee_, it was visible, since that towards the end of _February_ it was not three times as much remote from the Earth, than when it was in its _Perigee_, and that towards the end of _January_ it was not five times as much. {39}

In the interim, _saith he_, the other _Comet_ could be seen with the naked eye until _January_ 31. when it was more than ten times further remote, than in its _Perigee_, although it was not by far so bright, nor its streamer shining as this hath appeared.

He wishes, that all the changes that shall fall out in this _Comet_, might be exactly observ'd; because of its not being swift, and the Motion of the Earth very sensible, unless the _Comet_ be extreamly remote, we should find much more light from this, than the former Star, about the Grand Question, whether the _Earth_ moves or not; this Author having all along entertained himself with the hopes, that the Motion of _Comets_ would evince, whether the _Earth_ did move or not; and this very _Comet_ seemed to him to have by design appeared for that end, if it had had more _Latitude_, and that consequently we might have seen it before Day break. He wishes also, that, if possible, it may be accurately observed, whether it will not a little decline from its great Circle towards the _South_; Judging, that some important truth may be thence deduced, as well as if its motion retarded more, than the place of its _Perigee_ (which will be more exactly known when all the passed Observations shall have been obtained) and its greatest Motion do require.

He fears only, that it being then to rise at Break of Day, exact Observations cannot be made of it: but he would, at least have it sought with _Telescopes_, his _Ephemerides_ directing whereabout it is to be.

_April_ 10. it was to be over against the point of the _Triangle_, and from thence more _Southerly_ by more than two degrees; and _April_ 11. over against the bright Star of _Aries_, _April_ 17. over against the Stars of the _Fly_, a little more _Southerly_, and _May_ 4 it is to be over against the _Pleiades_, and about the fourth or fifth of the same Month, it is to be once more in _Conjunction_ with the _Sun_; after which time, the _Sun_ will move from it _Eastward_, and leave it towards the _West_; which will enable us to see it again at a better hour, provided the cleerness of the Day-break be no impediment to us. He addeth, that this Star must have been the third time in _Conjunction_ with the _Sun_, about the time when it first began to appear: and foresees, that from all these particulars many considerable consequences may be deduced. {40}

It will cut the _Ecliptick_ about the end of _July_, new Style, a little more _Eastwards_ than the _Eye_ of _Taurus_; at which time there will be no seeing of it, except it be with a _Telescope_.

It will be towards the _End_ of _April_, new style, twice as far distant as it was in _Perigee_, thrice as far, _May_ the fourth, four times, _May_ the eighteenth, and five times, _June_ the first, &c.

He would not have Men surprised, that there have been two _Comets_ within so short a time; seeing, _saith he_, there were four, at least three, in the Year 1618. and in other Years there have been two and more at the same time. What he adds about their signification, we leave to _Astrologers_ to dispute it with him. He concludeth with asking pardon, if he have committed mistakes, which he hopeth he shall obtain the sooner, because of the small time he hath had for these calculations; and he wishes that he could have made all the Observations himself, seeing that it is easie to fail, when one must trust to the Observations of others, whereof we know not the exactness: where he instanceth, that according to his Observations, the way of the _Comet_ should go neerer the Ecliptick than he hath marked it, even without having any great regard to the Refractions: but since he would subject himself to others, he hath made it pass a little higher, which, he saith, was almost insensibly so, in those few days that he was observing and writing, but that this may perhaps become sensible hereafter; which if it be so, he affirms that it will cut the _Ecliptick_ and _Equator_ sooner, than he hath marked it, &c. However, he thinks it convenient, to have given aforehand a common Notion of what will become of a _Comet_, to prepare men for all the Changes that may fall out concerning it: which he affirms he hath endeavoured to do; the rest being easie to correct, as soon as any good Observations, somewhat distant, have been obtained, considering, that there need but two very exact ones, a little distant when the Star is not swift, to trace its Way; although there must be at least three, to find out all the rest. But, then would he have it considered, that although his Method should be very exact, if there be not at hand Instruments big enough, and Globes good enough to trust to, nothing can be done perfectly in these kind of Predictions. {41}

* * * * *

_A Relation of the advice given by Monsieur _Petit_, Intendant of the Fortifications of _Normandy_, touching the Conjunction of the _Ocean_ and _Mediterranean_._

This Intelligent Gentleman, Monsieur _Petit_, having been consulted with, touching the Conjunction of the _Ocean_ and _Mediterranean_, delivers first the Proposition, and then giveth his thoughts upon it.

The Proposition is, That there being about two Leagues below _Castres_ in _Languedoc_ a Rivolet, called _Sor_, passing to _Revel_, there may by the means thereof be made a Communication of the two Seas, by joyning the Waters of this Rivolet by a Channel (to be kept full all the year long) with those of St. _Papoul_, and others, which fall into _Fresqueil_ (another small River) that runs into the _Aude_ below _Carcassone_, and go together to _Narbonne_, scituated upon the _Mediterranean_.

Having given the Proposition, he adds some particulars, to illustrate the same, before he declares his judgment upon it. For he relateth, that there is but one way, after the division of the Waters, to pass to the _Mediterranean_, which is by a Rivolet, called _Fresqueil_, that is conjoyn'd with the _Aude_: But, to pass to the _Ocean_, there are three; One, by _Riege_, entring into the _Caronne_ above _Tholouse_; the other, by _Lers_, passing on the side, and below the same Town; and the third, by _Sor_, falling into the River _Agoust_ under _Castres_, afterwards into the _Tarne_, and thence to _Montauban_, and lastly into the _Garonne_. And that, to compass this design, all these Rivers and Rivolets are first to be made Navigable unto their _Sluces_; that of _Aude_ and _Fresqueil_ for the _Mediterranean_, and one of the others, such as shall be chosen, for the _Ocean_. He addeth, that, as to the several Ways passing to the _Ocean_, all of them commended as proper and convenient, and the three Countries concerned therein, speaking every one for their advantage: Those of _Castres_ and {42} _Montauban_, are for the River _Agoust_; those of _Tholouse_, for _Riege_; and the rest, for _Lers_.

Now concerning his Opinion upon this Proposition, he thinks, that all that hath been represented touching this matter, can signifie very little, seeing that the main thing is wanting, which is the assurance, and certain and positive mensuration of the height and quantity of the Waters, necessary to fall into both the Channels of the _Aude_ and _Caronne_: that there must be plenty of that, to furnish at all times and alwayes the highest and first _sluces_, since what once issues thence, doth never enter again into them; and after some Boats are passed, if there should not be a sufficient supply for those that come after; either to go up, or to go down, all would stand dry, and Merchants and their commodities would stay long enough expecting the supply of Rains, to their great detriment. He concludeth therefore, that no knowing and discreet Person is able, in matters of this nature, to give a positive answer, without having before him a large and exact Topographical Map of those places, and of the sources of all the Rivolets, that are to supply the Water to the Head of the pretended Channel, together with a full account of the survey and mensuration of all the places, through which it is to pass; of the Nature of the Ground, whether it be stony, sandy, rocky, &c. of the exact level of all the places, where it is to be made, and of the several risings and depressions thereof, to be assured that the Water may be conveyed to the greatest rising, and to the highest _Sluce_; and lastly, of the quantity, that may be had at high, middle, and low Water, to have enough for all times; that all these things being first made out, 'tis then time enough to judge of the possibility of the thing, and to calculate the charges necessary for Execution.

This Artist having thus prudently waved this Proposition, diverts himself with reflecting upon several others of the like nature, among which he insists chiefly upon two, whereof one is that so much celebrated in _Egypt_; the other, of _Germany_. And he is of Opinion, that the most important of all is that, of conjoyning the _Red sea_ by the _Nile_ with the _Mediterranean_, which he looks upon as the most excellent conveniency to go into the _East Indies_ without doubling the _Cape of Good Hope_; and yet it {43} could not be executed by those great Kings of _Egypt_, that raised so many stupendious _Pyramids_; although in his Opinion the reasons alleged by _Historians_ to justifie them for having abandoned that undertaking are of no validity, and that the _Red Sea_ cannot be, as they feared, higher than the _Nile_, and therefore not indanger the inundation of _Egypt_.

The other Proposition was made to _Charles Magna_, _Anno_ 793. for joyning the _Euxine_ Sea and the _Ocean_ together, by a Channel, which was begun for that end, and designed to be 2000. paces long and 100. paces broad, betwixt the River _Altmull_, falling into the _Danube_ above _Ratisbone_, and the River _Rott_, passing at _Nurenberg_, and thence running into the _Main_, and so into the _Rhine_. But yet this also proved abortive, though there was great appearance of success at first.

* * * * *

_Of the Way of killing _Ratle-Snakes_._

There being not long since occasion given at a meeting of the _Royal Society_ to discourse of _Ratle Snakes_, that worthy and inquisitive Gentleman, Captain _Silas Taylor_, related the manner, how they were killed in _Virginia_, which he afterwards was pleased to give in writing, attested by two credible persons in whose presence it was done; which is, as follows.

The Wild _Penny-royal_ or _Ditany_ of _Virginia_, groweth streight up about one foot high, with the leaves like _Penny-royal_, with little blue tufts at the joyning of the branches to the Plant, the colour of the Leaves being a reddish green, but the Water distilled, of the colour of Brandy, of a fair Yellow: the Leaves of it bruised are very hot biting upon the Tongue: and of these, so bruised, they took some, and having tyed them in the cleft of a long stick, they held them to the Nose of the _Ratle-Snake_, who by turning and wriggling laboured as much as she could to avoid it: but she was killed with it, in less than half an hours time, and, as was supposed, by the scent thereof; which was done _Anno_ 1657. in the Month of _July_, at which season, they repute those creatures to be in the greatest vigour for their poison. {44}

* * * * *

_A Relation of Persons killed with subterraneous _Damps_._

This Relation was likewise made to the _Royal Society_, by that Eminent _Virtuoso_ Sir _R. Moray_, who was pleased, upon their desire, to give it them in writing; as followeth.

In a Coal-pit, belonging to the Lord _Sinclair_ in _Scotland_, where the Coal is some 18 or 20 foot thick, and antiently wasted to a great depth: The Colliers, some Weeks agoe, having wrought as deep as they could, and being to remove into new Rooms (as they call them) did, by taking off, as they retired, part of the Coal that was left as Pillars to support the Roof and Earth over it, so much weaken them, that within a short space, after they were gone out of the Pitt, the Pillars falling, the Earth above them filled up the whole Space, where the Colliers had lately wrought, with its ruins. The Colliers being here-by out of work, some of them adventured to work upon old remains of Walls, so near the old wastes, that striking through the slender partition of the Coal-wall, that seperated between them and the place, where they used to work, they quickly perceived their Errour, and fearing to be stifled by the bad Air, that they knew, possessed these old wastes, in regard not onely of the Damps, which such wastes do usually afford, but because there having for many years been a Fire in those wastes, that filled them with stifling fumes and vapors, retired immediately and saved themselves from the eruptions of the Damp. But next day some seven or eight of them came no sooner so farr down the staires, that led them to the place where they had been the day before, as they intended, but upon their stepping into the place, where the Air was infected, they fell down dead, as if they had been shott: And there being amongst them one, whose Wife was informed he was stifled in that place, she went down so far without inconvenience, that seeing her Husband near her, ventured to go to him, but being choaked by the Damp, as soon as she came near him, she fell down dead by him. {45}

This Story of Sir _R. Moray_ affirmed to have received from the _Earl_ of _Weymes_, Brother in Law to the Lord _Sinclair_, as it was written to him from _Scotland_.

* * * * *

_Of the _Mineral_ of _Liege_, yeilding both _Brimstone_ and _Vitriol_, and the way of extracting them out of it, used at _Liege_._

The Account of this _Mineral_, and of the way of extracting both _Brimstone_ and _Vitriol_ out of it, was procured from _Liege_, by the lately mentioned Sir _Robert Moray_ and by him communicated to the _Royal Society_, as follows.

The _Mineral_, out of which _Brimstone_ and _Vitriol_ are extracted, is one and the same, not much unlike Lead ore, having also oft times much Lead mingled with it, which is seperated from it by picking it out of the rest. The Mines resemble our _English_ Coal Mines dugg according to the depth of the _Mineral_, 15, 20, or more fathoms, as the Vein leads the Workmen, or the subterranean waters will give them leave, which in Summer so overflow the Mines, that the upper waters, by reason of the drought, not sufficing to make the Pumps goe, the Work ceases.

To make _Brimstone_, they break the Stone or Ore into small pieces, which they put into Crucibles made of Earth, five foot long, square and Pyramid-wise. The Entry is near a foot square. These Crucibles are laid sloaping, eight undermost, and seven above them, as it were betwixt them, that the Fire may come at them all, each having its particular Furnace or Oven. The _Brimstone_ being dissolved by the violence of the heat, drops out at the small end of the Crucible, and falls into a Leaden-Trough or Receptacle, common to all the said Crucibles, through which there runs a continual Rivolet of cold water, conveyed thither by Pipes for the cooling of the dissolved Sulphur, which is ordinarily four hours in melting. This done, the Ashes are drawn out by a crooked Iron, and being put into an Iron Wheel barrow, are carried out of the Hutt, and {46} being laid in a heap, are covered with other exiled or drained Ashes, the better to keep them warm; which is reiterated, as long as they make _Brimstone_.

To make _Coperas_ or _Vitriol_, they take a quantity of the said Ashes, and throwing them into a square planked pit in the Earth, some four foot deep, and eight foot square, they cover the same with ordinary water, and let it lye twenty four hours, or until an Egg will swim upon the liquor, which is a sign, that it is strong enough. When they will boyl this, they let it run through Pipes into the Kettles, adding to it half as much Mother-water, which is that water, that remains after boyling of the hardned _Coperas_. The Kettles are made of Lead, 4½ foot high, 6 foot long, and 3 foot broad, standing upon thick Iron Barrs or Grates. In these the Liquor is boyled with a strong Coal-fire, twenty four hours or more, according to the strength or weakness of the Lee or Water. When it is come to a just consistence, the fire is taken away, and the boyled liquor suffered to cool somewhat, and then it is tapp'd out of the said Kettles, through holes beneath in the sides of them, and conveyed through wooden Conduits into several Receptacles, three foot deep and four foot long (made and ranged not unlike our Tan-pits) where it remains fourteen or fifteen dayes, or so long till the _Coperas_ separate it self from the water, and becomes icy and hard. The remaining water is the above-mentioned Mother-water; and the elixed or drained Ashes are the Dregs, or _Caput mortuum_, which the Lee, whereof the _Vitriol_ is made, leaves behind it in the planked Pits.

* * * * *

_A further Account of Mr. _Boyle_'s Experimental _History_ of _Cold_._

In the first Papers of these _Philosophical Transactions_, some promise was made of a _fuller_ account, to be given by the next, of the _Experimental History of Cold_, composed by the Honourable Mr. _Robert Boyle_; it being then supposed, that this _History_ would have been altogether printed off at the time of publishing the {47} _Second_ Papers of these _Transactions_; but the Press, employed upon this Treatise, having been retarded somewhat longer than was ghessed, the said promise could not be performed before this time: wherein it now concerns the inquiring World to take notice, that this subject, as it hath hitherto bin almost totally neglected, so it is now, by this Excellent Author, in such a manner handled, and improved by near _Two hundred_ choice _Experiments_ and _Observations_, that certainly the _Curious_ and _Intelligent_ Reader will in the perusal thereof find cause to admire both the Fertility of a Subject, seemingly so barren, and the Author's Abilities of improving the same to so high a Degree.

But to take a short view of some of the particulars of this _History_, and thereby to give occasion to _Philosophical_ men, to take this Subject more into their consideration, than hitherto hath been done; the Ingenious Readers will here see,

1, That not only all sorts of _Acid_ and _Alcalizate_ Salts, and Spirits, even Spirit of Wine, but also Sugar, and Sugar of Lead mixed with Snow, are capable of freezing other Bodies, and upon what account they are so.

2, That among the Substances capable of being frozen, there are not only all gross sorts of Saline Bodies, but such also as are freed from their grosser parts, not excepting Spirit of Urine, the _Lixivium_ of Pot-ashes, nor Oyl of Tartar, _per deliquium_, it self.

3, That many very spiritous liquors, freed from their aqueous parts, cannot be brought to freeze, neither naturally, nor artificially: And here is occasionally mentioned a way of keeping _Moats_ unpassable in very cold Countries, recorded by _Olaus Magnus_.

4, What are the ways proper to estimate the greater or lesser Coldness of Bodies; and by what means we can measure the intensness of Cold produced by Art, beyond that, which Nature needs to employ for the freezing of Water; as also, in what proportion water of a moderate degree of Coldness will {48} be made to _shrink_ by Snow and Salt, before it begin by Congelation to _expand_ it self; and then, how to measure by the differing Weight and Density of the same portion of Water, what change was produced in it, betwixt the hottest time of Summer, and first glaciating degree of Cold, and then the highest, which our Author could produce by _Art_: Where an Inquiry is annex'd, whether the making of these kind of Tryals with the waters of the particular Rivers and Seas, men are to sail on, may afford any useful estimate, whether or not, and how much, ships may on those waters be safely loaden more in Winter, than in Summer. To which is added the way of making exact Discoveries of the differing degrees of Coldness in differing Regions, by such Thermometers, as are not subject to the alterations of the _Atmosphere's_ gravitation, nor to be frozen.

5. Whether, in Cold, the diffusion from Cold Bodies be made more strongly downwards, contrary to that of Hot Bodies: Where is delivered a way of freezing Liquors without danger of breaking the Vessel, by making them begin to freeze at the bottom, not the top.