Chapter D: E B O. A Rain-bow about the Sun, forming an entire Circle, but (2)

3. That afterwards continuing the Observations, he found the Spots of these two Faces to turn by little and little from _East_ to _West_, and to return at last to the same situation, wherein he had seen them first.

4. That S. _Campani_, having also observ'd at _Rome_ with Glasses of 50. _Palmes_ or about 35 _Foot_, likewise of his own contrivance, had seen in the same Planet the same _Phenomena_.

5. That sometimes he hath seen, during the same night, the two Faces of _Mars_, one, in the Evening, the other in the Morning.

6. That the Motion of these Spots in the inferior part of the apparent Hemisphere of _Mars_, is made from _East_ to _West_, as that of all the other Celestial Bodies, and is peform'd by Parallels, that decline _much_ from the _Equator_, and _little_ from the _Ecliptick_.

7. That the Spots return the next day to the same situation, 40. minuts later, than the day before; so that in every 36. or 37. daies, about the same hour, they come again to the same place.

8. He promises shortly to give us the particular _Tables_ of this Motion and of its Inequalities, together with the _Ephemerides_ themselves.

9. He represents, that some other _Astronomers_ have also made at _Rome_ several Observations of these Spots of _Mars_, from _March 14/24._ to _March 20/30._ with Glasses, wrought by _Eustachio Divini_, of 25. and 45. Palmes; Which Spots he makes little differing from his own, of the first Face; as will by and by appear, by the direction to the _Schemes_.

10. But he adds, that those other _Roman_ Astronomers, that have observ'd with _Divini's_ Glasses, will have the Conversion of _Mars_ to be performed, not in 24 h, 40 m. (as he maintains it is) but in about 13 h.

11. And to evince, that they are mistaken in these Observations of theirs; he alledges, That they assure that the Spots, which they have seen in this Planet, (by an _Eustachian_ Telescope) the 20/30 of _March_, were small, very distant from one another, remote from the middle of the Disk, and the _Oriental_ Spot was less, than the _Occidental_ (as is represented by the Fig. O; like that of the first Face of _Mars_.) whereas, on the contrary, {244} He (_Cassini_) pretends to evidence by his Observations, made at the same time at _Bononia_, that, the same day and hour, those Spots were very large, neer one another, in the midst of the Disk, the Oriental bigger than the Occidental (as appears by _Fig._ P, which is that of the second Face of _Mars_.)

12. Besides, he declares, that those _Astronomers_ were too hasty, in determining, after 5 or 6 Observations only, in how much time _Mars_ finish's his Revolution; and denies it to be perform'd in 13 hours: adding, that, though Himself had observ'd for a much longer time, than they; yet he durst not for a great while define, Whether _Mars_ made but _one_ Turn in 24 hours 40 minuts or _two_; and that all, that he could, for a long time affirm, was onely this, that after 24 h. 40 m. this Planet appear'd in the same manner he did before.

13. But since those first Observations, He affirms to have found cause to determine, that the Period of this Conversion is made in the said space of 24 h. 40 m; and not oftner than once within that time; Alledging for proof;

1. That, whereas _Febr._ 6. (st.n.) he saw the Spots of the first Face of _Mars_, moving from eleven of the Clock in the night, until break of day, they appear'd not afterwards in the Evening after the rising of that Planet (witness several intelligent persons, which he names, that were present at the Observations) Whence he infers, that after 12 hours and 20 minuts, the same Spots did not come about; since that the same, which in the morning were seen in the middle, upon the rising of _Mars_; after 13 or 14 hours, might have appear'd neer the Occidental Limb. But, because he might be imposed upon by Vapors, whilst _Mars_ was yet so neer the _Horizon_, he gives this other determination, _vid._

2. Whereas he saw the first Face of _Mars_ the 6 of _February_ at 11 of the clock of the night following; he did not see the same after 18 daies at the same hour; as he ought to have done, if the Period were absolved in the space of 12 h. 20 m.

3. Again, whereas he saw _Febr._ 24. in the Evening, the other Face of _Mars_, he could not see the same, the 13. and 15. day of _March_, to wit after 17 and 19 days; as he should have done, if the Revolution were made in the newly mention'd time.

4. Again, whereas the 27. of _March_ in the Evening he saw {245} the second Face of _Mars_, he could not see it the 14. and 16. of _April_.

From all which Observations he Judges it to be evident, that the Period of this Planets Revolution is not perform'd in the space of 12. hours 20, minutes, but in about 24 hours 40 minutes; more exactly to be determin'd by comparing distant Observations: And that those who affirm the former, must have been deceived by not well distinguishing the two Faces, but that having seen the second, taken it for the first.

All which he concludes with this Advertisement, that, when he defines the time of the Revolution of _Mars_, he does not speak of its _Mean_ Revolution, but onely of that, which he observ'd, whilst _Mars_ was opposite to the Sun; which is the shortest of all.

_The Figures of the _Principal_ Observations, represented in the Book
here discoursed of, may be seen in the annexed _Scheme_; _videl.__

K. _One of the Faces of _Mars_, as S. _Cassini_ observed it _March 3. (_st.n._) 1666_ in the Evening, with a Glass of 24 Palmes._

L. _The other Face, as he saw it _Febr. 14/24_ in the Evening._

M. _The first Face, as S. _Campani_ saw at Rome, _March 3. 1666_. in the Evening, with a Glass of 50 Palmes._

N. _The second Face, as the same _Campani_ observed it _March 18/28_. in the Evening._

O. _The figure of _Mars_ as it was seen at _Rome_ by a Telescope of _Divini_ of 45 Palmes, _March 20/30_._

P. _The Figure of the said Planet, as it was seen the same day and hour at Bononia by _Cassini_; being that of the second Face._

* * * * *

_Some Observations lately made at _London_ concerning the Planet _Jupiter_._

These, as they were made, so they were imparted, by Mr. _Hook_, as follows:

A. 1666, _June_ 26. between 3. and 4. of the Clock in the morning, I observed the Body of _Jupiter_ through a 60 foot-glass, and found the apparent Diameter of it through the Tube, to be somewhat more than 2. degrees, that is, about four {246} times as big, as the Diameter of the _Moon_ appears to the _naked_ Eye. I saw the Limb pretty round, and very well defin'd without radiation. The parts of the _Phasis_ of it had various degrees of Light. About a and f, the _North_ and _South_ poles of it (in the _Fig Q._) 'twas somewhat darker, and by degrees it grew brighter towards b. and e, two Belts or Zones; the one of which (b) was a small dark _Belt_ crossing the Body Southward; Adjoyning to which was a smal Line of a somewhat lighter part; and below that again, Southwards, was the great black _Belt c_. Between that, and e, the other smaller black Belt, was a pretty large and bright _Zone_; but the middle d, was somewhat darker than the edges. I perceiv'd about 3^{h.} 15^{m.} near the middle of this, a very _dark round Spot_, like that represented at g, which was not to be perceiv'd about half an hour before: And I observed it, in about 10. minutes time to be gotten almost to d, keeping equal distance from the _Satelles h_, which moved also Westwardly, and was joyn'd to the Disk at i, at 3^{h.} 25^{m.} After which, the Air growing very hazy, and (as appeared by the _Baroscope_) very light also (in weight) I could not observe it: So that it was sufficiently evident, that this black Spot was nothing else, save the shadow of the _Satelles h_, Eclipsing a part of the Face of Jupiter. About two hours before, I had observed a large darker spot in the bigger _Belt_ about k, which in about an hour or little more (for I did not exactly observe the time, nor draw the _Figure_ of it) moving Westwards, disappear'd. About a week before, I discover'd also, together with a Spot in the _Belt c_, another Spot in the _Belt e_, which kept the same way and velocity with that of the _Belt c_. The other three _Satellites_ in the time of this Eclipse, made by the _Satelles_, were Westwards of the Body of _Jupiter_; appearing as bright through the Tube, as the Body of _Jupiter_ did to the naked Eye, and I was able to see them longer through the Tube, after the day-light came on, than I was able to see the Body of _Jupiter_ with my naked eye.

* * * * *

_A late Observation about Saturn made by the same._

_June_ 29 1666. between 11. and 12. at night I observed the Body of _Saturn_ through a 60. foot Telescope, and found it {247} exactly of the shape represented in the _Figure_ R. The _Ring_ appear'd of a somewhat brighter Light than the _Body_; and the black lines a a, crossing the Ring, and b b crossing the Body (whether Shadows or not, I dispute not) were plainly visible: whence I could manifestly see, that the _Souther_-most part of the Ring was on _this_ side of the Body, and the _Northern_ part, behind, or covered by the Body.

* * * * *

_A Relation of a sad effect of Thunder and Lightning:_

This Relation was written by that worthy Gentleman, _Thomas Neale_ Esquire, (the then _High Sheriff_ of the County of _Hampshire_, when this disaster hapned) to a Friend of his in _London_, as follows;

On the 24 of _January_ 1665/6, one Mr. _Brooks_ of _Hampshire_, going from _Winchester_ towards his house near _Andover_ in very bad Weather, was himself slain by Lightning, and the Horse, he rode on, under him. For about a mile from _Winchester_ he was found with his Face beaten into the ground, one leg in the stirrup, the other in the Horses mane; his Cloaths all burnt off his back, not a piece as big as a handkerchief left intire, and his hair and all his body singed. With the force, that struck him down, his nose was beaten into his face, and his Chin into his Breast; where was a wound cut almost as low, as to his Navil; and his cloaths being, as aforesaid, torn, the pieces were so scatter'd and consum'd, that not enough to fill the crown of a hat could be found. His gloves were whole, but his hands in them sing'd to the bone. The hip-bone and shoulder of his Horse burn't and bruised; and his saddle torn in little pieces. This was what appear'd to the Coroners inquest, and so is likely to be as near truth, as any is to be had.

_So far this Letter_: Which, if it had come soon enough to the hands of the _Publisher_, would have been joyned to a like _Relation_, inserted in the next foregoing Papers (_Num._ 13.) of an accident hapn'd at a later time. With both which may be compared the Account, formerly published in Latin by the Learned Dr. _Charleton_, concerning the Boy, that was {248} Thunder-struck near _Nantwich in Cheshire;_ the Title of the Book being _Anatome Pueride Cælo tacti_: such Relations, when truly made, well deserving to be carefully recorded for farther consideration.

* * * * *

_Of some Books lately publish't._

_RELATIONS OF DIVERS CURIOUS VOYAGES_, by _Mons. Thevenot_, the third _Tome_, in _French_. This Book contains chiefly, the Ambassie of the _Dutch_ into _China_, translated out of the Dutch manuscript: A Geographical description of _China_, translated out of a Chinese Author by _Martinius_: And the Account, which the Directors of the Dutch East-India Company made to the States General, touching the state of affairs in the East-Indies, when their late Fleet parted from thence. To touch some things of a _Geographical_ and _Philosophical_ nature, contained therein, we shall take notice;

1. How the Kingdom of _China_ is peopled; there being according to the best computation (which is there made with singular care) above 58 millions of Men, not counting Magistrates, Soldiers, Priests, Eunuchs, Women and Children; so that it may not be altogether strange, if one should affirm, there were 200 millions of people, of all sorts, in that Kingdom.

2. That _Catay_ is nothing else, but the _Six_ Northern Provinces of _China_, separated from the other _Nine_, by the great River _KIANG_; and that the City _Cambalu_ is the same with that of _Peking_; the _Tartars_, who carry every three years their Tribute to the Emperor of _China_, constantly calling the said Provinces and City by those names of _Catay_, and _Cambalu_.

3. That _China_ is so well furnisht with Rivers, and cut Channels, that men may go from the most Southern to the most Northern part thereof by water, except one daies journey; as the Dutch Ambassadours did, embarking at _Canton_, which is 23d. 48m. Northern Latitude, and landing at _Peking_, which is about 40d; having only travell'd one daies journey over some Mountains of the Province _Kiamsi_.

4. That the people of _China_ are exceeding industrious {249} Husbandmen making, among other waies of improving their soile, great use of Flouding.

5. That the _Physicians_ of _China_ do cure Sicknesses with much ease, and in a short time: That they have very ancient Books of the nature and vertues of Herbs, Trees and Stones: That their Modern Physicians (as well as their Ancient ones did) write of the Prognosticks, Causes, Effects, &c. of Diseases. That their Remedies consist for the most part of _Simples_ and _Decoctions_, _Cauteries_, _Frictions_; without the use of _Bloud letting:_ That they have such an excellent skill and method in feeling the _Pulse_, that by the means thereof they discover even the most latent causes of Diseases; taking a good half hour, when they visit a Patient, in feeling and examining his Pulse: That they prescribe much the use of _The_; and the drinking alwayes warme, whatever they drink: To the custome of both which it's imputed, that the inhabitants of _China_ do spit very little, nor are subject to the Stone or Gout: That they prise highly the Root _Ginseng_, as an extraordinary Restorative and Cordiall, recovering frequently with it agonizing persons; one pound of it being paid with 3 pounds of silver. As for their _Chymists_, (of which they have also good store) they go beyond ours, promising not only to make Gold, but to give Immortality.

6. That their _Nobility_ is raised from Learning and Knowledge, without regard to Bloud or Parentage, excepting the Royall Family.

7. That in _CHEKIAN_, a maritime Province, whence is the shortest cut of _China_ to _Japan_, is the best and plentifullest _Silk-trade_ in the world: And that there every year the Mulberries are cutt, and kept down, that they grow not into Trees for the easier gathering of the Leaves, there being a _double_ Silk-harvest in that Country, as there is in severall other parts of the East-indies; (both which there is hope, will shortly be imitated in _Virginia_.)

8. That the way of making _Porcelane_ is this: (_Which is the rather inserted here, because it agrees so well with an Account, we received a while since from a very Curious and intelligent Person of Amsterdam._) There is in the Province of _Nankin_ a Town, call'd {250} _Goesifols_ whence they draw the Earth for _Porcelaine_, which is found between the Rocks of Mountains. This Earth they beat very small, and stamp it to a very fine Powder, and then put it into Tubs fill'd with water; where the finest part sinks to the bottom. Afterwards 'tis kneaded in the form of small Cubes, of the weight of about 3. _Catti_ (a _Catti_ being 20 Ounces.) These pieces thus wrought are sold to the people, that commonly in great numbers fetch them, coming from the Town _Sintesimo_ (otherwise _Jontiou_) in the Province of _Kiansy_, being about 50 miles distant from _Wotsing_, neer the City _KIANSY_; which people transport them to their homes, and there bake them in this manner: They heat their Ovens well, for the space of 15 daies successively, and then keep them so close, that no Air may get in; and after 15 _other_ daies are pass'd, they open the Oven in the presence of an Officer, who takes every fifth vessel of each fashion for the service of the Emperor: Which done, the rest is sold to those of _Ucienien_, whence it is transported all over the Country. So that the Earth is not prepared, in _Nankin_, where 'tis found, because the people of that Province have not the skill of working it, as the other above-mention'd; who also alone have the Art of coloring it, which they keep as a great Secret, not teaching it to any, but their Children and next Kindred.

9. That _Musk_ is nothing else, but the Testicles of a Beast like a Dear, found in the Province of _Honan_; and that, when tis good and unmixt, as it comes from the Animal, they sell it even in _Nankin_ and _Pekin_, for 30. or 35. _Teyls_ (that is, about so many Crowns) the _Catti_.

Many other curious informations might be borrow'd from this Author, concerning the Customs, Studies, Exercises of the _Chinese_; of the number of the people of each Province; of the Natural productions of the Earth and Rivers there; of the Structure and Antiquity of their Wall; of the Magnificence of their Porcelain Tower &c.; but, remitting for these things to the Book it self, we shal only add a piece of Oeconomy, used by the _Holland_-Merchants in their Commerce with _China_, which is, that they dry abundance of Sage-leaves, role them up, and {251} prepare them like _The_, and carrying it to _China_, as a rare drogue, get for one pound of it, fourtimes as much _The_.

_A DISCOURSE ABOUT THE CAUSES OF THE INUNDATION OF THE NILE_, in _French_. The Author of this Book is Monseiur _dela Chambre_, who being perswaded from several Circumstances, that accompany the Overflowing of this River, that it cannot proceed from Rain, ventures to assign for a Cause of _it_, and of all the other effects that happen at the time of its swelling, the _Niter_, wherewith that water abounds.

The discourse having six parts, the Author endeavours to shew in the

_First_, that the Waters of the _Nile_ are Nitrous, explicating the Nature of Salt, and Saltpeter, and imputing the fertility of the Earth, as well us the fecundity of Animals, to Salt. Where he shews, that all things, that serve to improve Land, are full of Salt; and that 'tis observ'd, that grain steep'd in Vrine, before sowing, rises sooner, and becomes fuller and stronger, than else. Adding, that that, which renders the Seed of Animals prolifick, is, that one of the _Spermatick_ veins hath its Origine from the _Emulgent_, through which the Nitrous and Saline Serosities, that discharge themselves into the Kidneys and Bladder, do pass.

In the _Second_, he examins, what is Fermentation, and how 'tis perform'd; affirming, that, what thrusts forth Plants in the Spring, is, that the Earth being fermented by the _Niter_, it harbours, the Nitrous spirits insinuate themselves into their Pores.

In the _Third_ he treats of all the Circumstances, observable in the Inundation of the Nile. 'Tis affirm'd, that 3 or 4 days before that River begins to overflow, all its water is troubled: that then there falls a certain Dew, which hath a fermenting vertue, and leavens a Paste exposed to the Air: that the Mud, which has been drawn out of the water, grows heavier, when the overflowing begins, then it was before, and that by the increase of the weight of that Mud, they judge of the greatness of the approaching inundation. The Author pretends, that {252} the Niter, which the _Nile_ is stored with, is the cause of all these strange effects, and of many others, by him alledged. For, _saith he_, when the Nitre is heated by the heat of the Sun, it ferments, and mingling with the water, troubles it, and swells it, and makes it pass beyond its banks; after the same manner, as the Spirits in new Wine render it troubled, and make it boyle in the vessel. And it seems not likely to him, that the Mud, found in the _Nile_, should come a far off; for then it would at last so raise the banks of this River, that it would not be able to overflow them any longer. Whereas 'tis more than 2000 years, that the banks thereof are not grown higher, there being now requisite but 16. cubits for overflowing the Land, no more than there was in the time of _Herodotus_. Which shews, _saith he_, that this Mud is nothing but a volatil _Niter_, which exhaling, doth not increase the Earth. As for the _Ægyptian_ Dew, and the increase of the weight of the Mud, he adscribes them to the same Cause. For the spirits of Nitre abounding in the _Nile_, when raised into the Air with the vapors, that exhale continually from this River, there is made out of their mixture, a Dew, that refreshes the Air, makes sickness to cease, and produces all those admirable effects, that make the _Ægyptians_ wish for it so passionately. And the same spirits of Niter, being joyned to the Paste, and to the Mud, raise the one, and augment the weight of the other. That, which Mr. _Buratini_ observes, that at the time of this inundation, the Niter-pits of the neighboring places vomit out liquid Niter, and that one may see issue out of the Earth abundance of Chrystals of Nitre, is alledged to fortify this conjecture; Which is yet more confirm'd by the Fertility, communicated to the Earth by the Mud of this River. For, plants do grow there in such abundance, that they would choak one another, if it were not remedied by throwing Sand upon the Fields; insomuch that the _Ægyptians_ must take as much pains to spread Sand to lessen the fatness of their Land, as other Nations do, to spread dung or other manure upon theirs to increase the fatness.

In the _Fourth_ and _Fifth_, the Author undertakes to prove, that all those strange effects cannot be attributed to Rain or Snow, {253} and that the overflowing of the _Nile_ always happens at a certain day.

In the _Last_, he alledges some Relations, serving to confirm his Opinion; Which are too long here to insist upon.

_DE PRINCIPIIS ET RATIOCINATIONE GEOMETRARUM, Contra Fastum Professorum Geometriæ;_ Authore _Thoma Hobbes_. It seems, that this Author is angry with all Geometricians, but himself; yea he plainly saith in the dedication of his Book, that _he invades the whole Nation of them_; and unwilling, it seems, to be call'd to an account for doing so; He will acknowledge no judge of _this_ Age; but is full of hopes, that posterity will pronounce for him. Mean while he ventures to advance this _Dilemma_; _Eorum qui de iisdem rebus mecum aliquid ediderunt, aut solus insanio Ego, aut solus non insanio; tertium enim non est, nisi (quod dicet forte aliquis) insaniamus omnes._ Doubtless, one of these will be granted him.

As to the Book it self, he professes, that he doth not write it against _Geometry_, but _Geometers_; and that his design in it is, to shew, That there is no less uncertainty and falsity in the writings of _Mathematicians_, than there is in those of _Naturalists_, _Moralists_, &c., though he judges, that _Physicks_, _Ethicks_, _Politicks_, if they were well demonstrated, would be as certain as the _Mathematicks_.

Attacking the Mathematical Principles as they are found in Books, and withall some Demonstrations, he takes to task _Euclid_ himself, instead of all, as the Master of all Geometricians, and with him his best interpreter, _Clavius_, examining in the _First_ place, the _Principles_ of _Euclid_: _Secondly_, Declaring false, what is superstructed upon them, whether by _Euclid_, or _Clavius_, or any _Geometer_ whatsoever that hath made use of those or other (as he is pleased to entitle them) _false_ Principles. _Thirdly_, Pretending, that he means so to combat all, both Principles and Demonstrations, undertaken by him, as that he will substitute better in their room, least he should seem to undermine the Science it selfe. {254}

The particulars, which he undertakes to reform, are,

_Punctum._
_Linea._
_Terminus._
_Linea Recta._
_Superficies._
_Superficiei Termini._
_Superficies Plana,_
_Angulus_ (Where he is large upon the _Angulus Contactus._)
_Petitio prima Elem. 1. Euclidis._
_Ratio._
_Radix & Latus._
_Prop. 16. El. 3._
_Dimensio Circuli._
_Magnitudo Circuli Hugeniana._
_Sectio Anguli._
_Ratio, quam habet recta composita ex Radio & Tangente 30. grad, ad
Radium ipsum._
_Propos. 47æ. Elem. 1. Demonstratio._
_Addita est Appendix de Mediis proportionalibus in genere._

_KING SALOMONS POUTRAITURE OF OLD AGE_; by _John Smith_, M.D. This Treatise being a _Philosophical_ Discourse, though upon a _Sacred_ Theme, may certainly claim a place among _Philosophical_ Transactions. Not here to mention the many other learned Notes, this Worthy Author gives upon that Hieroglyphical Description of Old Age, made by that Royal Pen-man of _Ecclesiastes_, cap. 12. We shall onely take notice of that surprizingly Ingenious one, there to be met with, concerning the Antiquity of the Doctrine of the _Blood's Circulation_: King _Salomon_, who lived neer 2700 years agoe, using such expressions, as may, to a considering Reader, very probably denote the same Doctrine, which the Sagacious Dr. _Harvey_ has of late years so happily brought to light, and introduced into all the most Ingenuous Societies of Learned men: The _Pitcher_, mention'd in the quoted place, being Interpreted for the _Veines_, and the _Fountain_ for the _Right Ventricle of the Heart_, as the _Cistern_ for the _Left_; the _Wheele_, there spoken off, manifestly importing a _Circulation_, made by the _Great Artery_ with its Branches, the principal Instrument thereof.

* * * * *

Printed with Licence for _John Martyn_, and _James Allestry_, Printers to the Royal Society. 1666.

{255}

* * * * *

_Num._ 15.

PHILOSOPHICAL _TRANSACTIONS._

* * * * *

_Wednesday_, _July_ 18. 1666.

* * * * *

The Contents.

_A new Experiment, shewing, How a considerable degree of Cold may be
suddenly produced without the help of _Snow_, _Ice_, _Haile_, _Wind_,
or _Niter_, and that at any time of the year. An Account of two Books,
lately printed in _London_; whereof the one is entituled, _EUCLIDIS
ELEMENTA GEOMETRICA, novo ordine ac Methodo demonstrata_; the Author
_Anonymus_. The other, _THE ENGLISH VINE-YARD VINDICATED_, by _JOHN
ROSE_._

* * * * *

_A new Frigorifick Experiment shewing, how a considerable degree of _Cold_ may be suddenly produced without the help of _Snow_, _Ice_, _Haile_, _Wind_, or _Niter_, and that at any time of the year._

This subject will it self, 'tis presumed, without any other _Preamble_, speak the Cause, why this present Paper is publish't at this (unusual) time of the Month: though, by the by, it may not be amiss to add on this occasion, that the Publisher of these _Tracts_ never meant so to confine himself to a _Set_ time, as not to retain the Liberty of taking any other, when there is occasion. And there being one given him, before another Month is come in, he does without any scruple or delay comply therewith, presenting the Curious with an Experiment which he thinks is both seasonable, and will not be unwellcome to them; furnish't out of the Ample Magazin of that Philosophical Benefactor, the Noble Mr. _Boyle_; Concerning which, thus much is further thought requisite to intimate on this occasion, that it, and some others of the same Gentlemans, that have been, and may be, mentioned in the _Transactions_, belong to certain Treatises, the Author hath lying by him; but that yet he denys not {256} to communicate them to his Friends, and to allow them to dispose thereof, upon a hope, that equitable Readers will be ready to excuse, if hereafter they should appear also in the Treatises they belong to, since he consents to this Anticipation, but to comply with those, that think the imparting of real and practical Experiments, may do the Publick some Service, by exciteing and assisting mens Curiosity in the interim.

As for the Experiment, you saw the other day at my Lodgings, though it belongs to some Papers about _Cold_, that (you know) could not be Publish't, when the rest of the _History_ came forth, and therefore was reserved for the next _Edition_ of that Book; yet the Weather having been of late very hot, and threatning to continue so, I presume, that to give you here in compliance with your Curiosity an Account of the Main and Practical part of the Experiment, may enable you to gratify not onely the Curious among your Friends, but those of the Delicate, that are content to purchase a Coolness of Drinks at a somewhat chargeable rate.

You may remember, that the Spring before the last, I shew'd you a particular Account of a way, wherein by a certain substance obtain'd from _Sal Armoniack_, I could presently produce a considerable degree of _Cold_, and that with odd Circumstances, without the help of _Snow_, _Ice_, _Niter_ &c. But that Experiment being difficult and costly enough, and design'd to afford men _Information_, not _Accomodations_, I afterwards tryed, what some more cheap and facile mixtures of likely Bodies with _Sal Armoniack_ would do towards the Production of Cold, and afterwards I began to consider, whether to that purpose alone (for my first experiment was design'd to exhibite other _Phænomena_ too) those mixtures might not without inconvenience be omitted: and I was much confirm'd in my conjecture, by an accident, which was casually related to me by a very Ingenious Physician of my acquaintance, but not to be repeated to you in few words, though he complain'd, he knew not what to make of it.

Among the several ways, by which I have made infrigidating Mixtures with _Sal Armoniack_, the most simple and facile is this; Take one pound of powder'd _Sal Armoniack_ and about three Pints (or pounds) of Water, put the Salt into the Liquor, _either_ altogether, if your design be to produce an intense, though {257} but a short coldness; _or_ at two, three, or four several times, if you desire, that the produced coldness should rather last somewhat longer than be so great. Stirre the powder in the Liquor with a stick or whalebone (or some other thing that will not be injur'd by the fretting Brine, that will be made) to hasten the dissolution of the Salt; upon the quickness of which depends very much the intensity of the Cold, that will ensue upon this Experiment. For the clearing up whereof, I shall annex the following particulars.

[Sidenote: * _In the History of Cold._]

1. That a considerable degree of Cold is really produced by this operation, is very evident: _First_ to the touch; _Secondly_, by this, that if you make the Experiment (as for this reason I sometimes chuse to do) in a Glass-Body or a Tankard, you may observe, that, whilst the Solution of the Salt is making, the outside of the Metalline Vessel will, as high as the mixture reaches within, be bedew'd (if I may so speak) with a multitude of little Drops of Water as I have * elsewhere shown that it happens, when mixtures of Snow and Salt, being put into Glasses or other Vessels, the aqueous vapors that swim to and fro in the Air, and chance to glide along the sides of the Vessels, are by the coldness thereof condens'd into Water. And in our Armoniack Solution you may observe, that if you wipe off the Dew from any particular part of the outside of the Vessel, whilst the solution does yet vigorously goe on, it will quickly collect fresh Dew, which may be sometimes copious enough to run down the sides of the Vessel. But _Thirdly_, the best and surest way of finding out the Coldness of our Mixture is that, which I shew'd you by plunging into it a good seal'd Weatherglass furnish't with tincted Spirit of Wine. For the Ball of this being put into our frigorifick mixture, the Crimson Liquor will nimbly enough descend much lower, than when it was kept either in the open Air, in common Water, of the same temper with that, wherein the _Sal Armoniack_ was put to dissolve. And if you remove the Glass out of our Mixture into common water, the tincted Spirit will, (as you may remember, it did) hastily enough reascend for a pretty while, according to the greater or lesser time, that it continued in the _Armoniack_ Solution. And this has succeeded with me, when instead of removing the Mixture into _Common_ Water, I removed it into water newly impregnated with _Salt-peter_.

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2. The _Duration_ of the Cold, produc'd by this Experiment, depends upon several Circumstances; as _First_, upon the Season of the year, and present temperature of the Air; For, in Summer and Hot weather the Cold will sooner decay and expire. _Secondly_, upon the Quantity of Salt and Water: For, if both these be great, the effect will be as well more lasting, as more considerable. _Thirdly_, for ought I yet know, we may here add the Goodness & Fitness of the particular parcel of Salt, that is imploy'd; for, though it be hard to discern beforehand, which will be the more, and which the less proper; yet some trials have tempted me to suspect, that there may be a considerable disparity, as to their fitness to produce Cold, betwixt parcels of Salt, that are without scruple look't upon as Sal Armoniack: Of which difference it were not perhaps very difficult to asign probable reasons from the Nature of the Ingredients of this compound Concrete, and the wayes of preparing it. But the Duration of the Cold may be conceived to depend also. _Fourthly_, upon the Way of putting in the Salt into the Water. For, if you cast it in all at once, the Water will sooner acquire an intense degree of Coldness, but it will also the sooner return to its former temper; Whereas, if you desire but an inferiour degree of that Quality, but that may last longer (which wil usually be the most convenient for the Cooling of Drinks), then you may put in the Salt by little and little. For, keeping a long Weather-glass for a good while in our impregnated Mixture, I often purposely try'd, that, when the tincted liquor subsided but slowly, or was at a stand, by putting in, from time to time, 2 or 3. spoonfuls of fresh Salt, and stirring the Water to quicken the Dissolution, the Spirit of Wine would begin again to descend, if it were at a stand or rising, or subside much more swiftly than it did before. And if you would lengthen the Experiment, it may not be amiss, that part of the Sal Armoniack be but grosly beaten, that it may be the longer in dissolving, and consequently in Cooling the Water. Whilst there are dewy drops produced on the outside of the Vessel, 'tis a sign, that the Cold within continues pretty strong; for when it ceases, these drops especially in warm weather, will by degrees vanish. But a _surer_ way of measuring the duration of the Cold, is, by removing from time to time the Seal'd Weather-glass out of the Saline Mixture into the same common Water, with part of which it was made. And though it be not easie to determin any thing particularly about this matter; yet it may somewhat assist you in your Estimates, to be inform'd, That I have in the Spring by a good Weather-glass found a sensible adventitious Cold made by a pound of Sal Armoniack at the utmost, to last about 2 or 3 hours.

3. To cool Drinks with this Mixture, you may put them in _thin_ Glasses, the thinner the better; which (their orifices being stopp'd, and still kept above the Mixture) may be moved to and fro in it, and then be immediately pour'd out to be drunk: Though when in the Glass, I imployed, was conveniently shap'd as, like a Sugar-loaf, or with a long Neck, I found it not amiss to drink it out of that, without pouring it into any other; which can scarce be done without lessning the Coolness. The refrigeration, if the Glass viall be convenient, is quickly perform'd: And if one have a mind to cool his hands, he may readily do it by applying them to the outside of the Vessel, that contains the refrigerating Mixture; by whose help, pieces of Chrystal, or Bullet for the cooling of {259} the Mouths or Hands of those patients, to whom it may be allow'd, may be potently cool'd, and other such refreshments may be easily procur'd.

4. How far Sal Armoniack, mingl'd with Sand or Earth, and not dissolv'd, but only moistn'd with a little Water sprinkl'd on it, will keep Bottles of Wine or other liquors more coole, than the Earth or that Sand alone will do, I have not yet had opportunity by sufficient trials fully to satisfie my self, and therefore resign that Enquiry to the Curious.

5. For the cooling of Air, and Liquors, to adjust Weather-glasses (to be able to do which at all times of the year, was one of the chief aimes, that made me bethink my self of this Experiment;) or to give a small quantity of Beer &c. a moderate degree of coolness, it will not be requisite, to employ neer so much as a whole pound of Sal Armoniack at a time. For, you may easily observe by a seal'd Weather-glass, that a very few ounces, well pouder'd and nimbly dissolv'd in about 4. times the weight of Water, will serve well enough for many purposes.

6. And that you may the less, scruple at this, I shall tell you, that even before and after Midsummer, I have found the Cold producible by our Experiment to be considerable and useful for refrigerating of Drinks, &c. but if the Sal Armoniack be of the fittest sort (for I intimated above, that I suspected, 'tis not equally good) and if the season of the year do make no disadvantagious difference, the degree of Cold, that may be produced by no more than one pound (if not by less) of Sal Armoniack, may, within its own Sphere of Activity, be much more vehement, than, I presume, you yet imagine, and may afford us excellent Standards to adjust seal'd Weather glasses by; and for several other purposes, For I remember that in the Spring, about the end of _March_, or beginning of _April_, I was able with one pound of Sal Armoniack, and a requisite proportion of Water, to produce a degree of Cold much greater, than was necessary the preceding Winter, to make it frosty Weather abroad; nay I was able to produce real Ice in a space of time, almost incredibly short. To confirm which particulars, because they will probably seem strange to you, I will here annex the Transcript of an entry, that I find in a Note book of the _Phænomena_ and success of one of those Experiments, as I then tryed it; though I should be asham'd to expose to your perusal a thing so rudely pen'd; if I did not hope, you would consider, that 'twas hastily written onely for my own Remembrance. And that you may not stop at any thing in the immediately annext Note, or the two, that follow, it will be requisite to premise this Account of the seal'd Thermoscope; (which was a good one) wherewith these Observations were made; That the length of the Cylindrical pipe was 16. Inches; the Ball, about the bigness of a somewhat large Walnut, and the Cavity of the Pipe by guess about an eight or ninth part of an inch Diameter.

The First Experiment is thus registered. _March_ the 27th, in the Seal'd Weather glass, when first put into the Water, the tincted Spirit rested at 8-5/8 inches; being suffered to stay there a good while, and now and then stirr'd to and fro in the Water; it descended at length a little beneath 7-5/8 inches; then the _Sal Armoniack_ being put in, within about a quarter of an hour or a little more it descended to 2-11/16 inches, but before that time, in half a {260} quarter of an hour it began manifestly to freeze the vapours and drops of water on the outside of the Glass. And when the frigorifick power was arriv'd at the height, I several times found, that water, thinly plac'd on the outside, whilst the mixture within was nimbly stirr'd up and down, would freeze in a quarter of a minute (by a Minute-watch.) At about ¾ of an hour after the infrigidating Body was put in, the Thermoscope, that had been taken out a while before, and yet was risen but to the lowest freezing mark, being again put in the liquor, fell an inch beneath the mark. At about 2½ houres from the first Solution of the Salt I found the tincted liquor to be in the midst between the freezing marks, whereof the one was at 5½ inches (at which height when the Tincture rested, it would usually be, some, though but a small, frost abroad;) and the other at 4¾ inches; which was the height, to which strong and durable Frosts had reduced the liquor in the Winter. At 3 hours after the beginning of the Operation, I found not the Crimson liquor higher than the upper Freezing mark newly mention'd; after which, it continued to rise very slowly for about an hour longer; beyond which time I had not occasion to observe it.

Thus far the _Note-book_; wherein there is mention made of a Circumstance of some former Experiments of the like kind, which I remember was very conspicuous in this newly recited. For, the frigorifick mixture having been made in a Glass body (as they call it) with a large and flattish bottom, a quantity of water, which I (purposely) spilt upon the Table, was by the operation of the mixture within the Glass, made to freeze, and that strongly enough, the bottom of the Cucurbite to the Table; that stagnant liquor being turn'd into solid ice, that continued a considerable while unthaw'd away, and was in some places about the thickness of a half Crown piece.

Another Observation, made the same Spring, but less solemn, as meant chiefly to shew the Duration of Cold in a high degree, is recorded in these terms: The first time, the Seal'd Weather-glass was put in, before it touch'd the common water, it stood at 8-1/8, having been left there a considerable while, and once or twice agitated the water, the tincted liquor sunk but to 7-7/8, or at furthest, 7-6/8; then the frigorifick liquor being put into the water with circumstances disadvantagious enough in (about) half a quarter of an hour the tincted liquor fell beneath 3¾, and the Thermoscope, being taken out, and then put in again, an hour after the water had been first infrigidated subsided beneath 5 inches, and consequently within ¼ of an inch of the mark of the strongly freezing weather.

7. Whereas the grand thing, that is like to keep this Experiment from being as generally _Useful_, as perhaps it will prove _Luciferous_, is the Dearness of Sal Armoniack, two things may be offered to lessen this Inconvenience. For _first_, Sal Armoniack might be made much cheaper, if instead of fetching it beyond-sea, our Country-men made it here at home; (which it may easily be and I am ready to give you the Receipt, which is no great Secret.) But _next_, I considered, that probably the infrigidating vertue of our mixture might depend upon the peculiar Texture of the Sal Armoniack whereby, whilest the Water is dissolving it, either some Frigorifick particles are extricated and excited or (rather) some particles which did before more agitate the minute parts of the water, are expell'd (or invited out by the ambient Bodies) or {261} come to be clogg'd in their motion: Whence it seem'd reasonable to expect that upon the Reunion of the Saline particles into such a Body, as they had constituted before, the redintegrated Sal Armoniack having, neer upon, the same Texture, would, upon its being redissolv'd, produce the same, or a not much inferior degree of Coldness: And hereupon, though I well enough foresaw that an Armoniack solution, being boyl'd up in Earthen vessels (for Glass ones are too chargeable) would, by piercing them, both lose some of the more subtle parts, and thereby somewhat impaire the texture of the rest; yet I was not deceiv'd in Expecting, that the dry Salt, remaining in the pipkins, being redissolv'd in a due proportion of water, would very considerably infrigidate it; as may further appear by the Notes, which for your greater satisfaction you will find here subjoyn'd, as soon as I have told you, that, though for want of other vessels I was first reduc'd to make use of Earthen ones, and the rather, because some Metallin Vessels will be injur'd by the dissolv'd Sal Armoniack, if it be boyl'd in them; yet I afterwards found some conveniencies in Vessels of other Mettall, as of Iron; whereof you may command a further Account.

_March_ the 29th, the Thermoscope in the Air was at 8-7/8 inches; being put into a somewhat large evaporating glass, fill'd with water, it fell (after it staid a pretty while, and had been agitated in the liquor) to 8. inches: then about half the Salt, or less, that had been used _twice_ before, and felt much less cold than the water, being put in and stirr'd about, the tincted Spirit subsided with a visible progress, till it was faln manifestly beneath 4. inches; and then, having caused some water to be freshly pump'd and brought in; though the newly mention'd Solution were mixt with it, yet it presently made the Spirit of Wine manifestly to ascend in the Instrument, much faster, than one would have expected, &c.

And this much may suffice for this time concerning our _Frigorifick_ Experiment; which I scarce doubt but the _Cartesians_ will lay hold on as very favourable to some of their Tenents; which you will easily believe, it is _not_ to the Opinion, I have elsewhere oppos'd, of those Modern Philosophers, that would have _Salt-petre_ to be the _Primum Frigidum_: (though I found by trial, that, whilst 'tis actually dissolving, it gives a much considerabler degree of Cold, than otherwise.) But about the Reflexions, that may be made on this Experiment, and the Variations, and Improvements & Uses of it, though I have divers things lying by me; yet, since you have seen several of them already, and may command a sight of the rest, I shall forbear the mention of them here, not thinking it proper, to swell the bulk of this Letter with them.

* * * * *

_An Account of two Books lately printed in London._

I. _EUCLIDIS ELEMENTA GEOMETRICA, novo ordine ac methodo demonstrata._ In this compendious and pretty Edition, the Anonymous Author pretends to have rendred these Elements more expeditious; by bringing all together into one place, what belongs to one and the same subject: Comprising 1. what _Euclid_ hath said of _Lines_, Streight, Intersecting one another, and Parallel. 2. What he hath demonstrated of a _Single Triangle_, and of _Triangles Compared_ one with another. 3. What of the _Circle_, and its Properties. 4. What of _Proportions_ in Triangles and other Figures. 5. What of _Quadrats_ and _Rectangles_, made of Lines diversly {262} cut. 6. What of _Plane Superficies_'s. 7. What of _Solids_. After which follow the _Problems_. The _Definitions_ are put to each _Chapter_ as need requireth. The _Axioms_, because they are few, and almost every where necessary, are not thus distributed in _Chapters_. The _Postulata_, are not subjoyn'd to the _Axioms_, but reserv'd for the _Problems_, the Author esteeming, that they being _practical_ Principles, had only place in _Problems_.

This for the _Order:_ As to the _Manner_ of Demonstrating, One and the same is observ'd in most Propositions; all with much brevity; to the end, that what is not of it self difficult, may not be made so, by multitude of Words and Letters.

II. _THE ENGLISH VINE-YARD VINDICATED._ The Author (Mr. _John Rose_, his Majesties Gardener at his Royal Garden in St. _James_'s) makes it his business in this small Tract (a very thin Pocket-book) by a few short Observations made by himself, to direct _Englishmen_ in the _Choice_ of the _Fruit_, and the _Planting_ of Vine-yards; heretofore very frequently cultivated, though of late almost quite neglected by them.

He discourses skilfully, 1. Of the _severall sorts_ of _Vines_, and what _Grapes_ are most sutable to the _Climate_ of _England_; where he chiefly commends the small _Black-grape_, or _Cluster-grape_; the _Parsley-grape_; the White _Muscadine_; the _Frontiniack_; and a new _White-grape_, with a red Wood and a dark green Leaf: All these being early ripe fruit. 2. Of the _Soyle_, and _Scituation_ of a Vine-yard in _England_: Where, as to the _First_, he pitches upon a _Light Soile_, having a bottom of _Chalk_ or _Gravel_, and given to _Brambles_ observing, that no Plant whatsoever is so connatural to the Vine for Soyl, as the _Bramble_. As for the _Scituation_ he chooses that side or declivity of a Hill, that lies to the _South_ or _Southwest_; and is favoured with _other Hills_ somewhat higher, or _Woods_ on the _North_ and _East_, to break the rigour of those quarters. This direction he thinks of that importance, that he affirms, that the discouragement of the Culture of Vines in _England_ has only proceeded from men's misinformation on this material article of _Choice_ of _Soyle_ and _Scituation_. 3. How to _prepare_ the Ground for the Plantation, _vid._ by plowing up the _Swarth_ in _July_, and by disposing the _Turf_ in _small_ heaps, and so burning them, and spreading the ashes over the Land; care being taken, that by heaping too much materials together, the Earth be not over-burnt by the excessive heat and fire, which they require to reduce them to ashes.

What is added, of the Manner of planting the _Sets_; of Dressing, Pruning, and Governing the Plantation; of the Ordering and Cultivating the Vine-yard after the first four years, till it needs renewing; as also of the _manner_ and _time_, how and when to manure the Vine-yard, with Compost, will be better understood from the Book it self, than can be here described; the Author pretending, that, those few observations of his, as the native production of his own Experience, being practised with care, the Vine-yards in _England_ may be planted, govern'd and perpetuated with undoubted success; and offering withall to furnish those, that have a desire to renew this Culture, and to store their grounds with _Sets_ and _Plants_ of all those sorts, which he recommends; he having a plentiful _stock_ of them all.

* * * * *

Printed with Licence for _John Martyn_, and _James Allestry_, Printers to the Royal Society. 1666.

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* * * * *

_Num._ 16.

PHILOSOPHICAL _TRANSACTIONS._

* * * * *

_Munday_, _August_ 6. 1666.

* * * * *

The Contents.

_An essay of Dr. _John Wallis_, exhibiting his _Hypothesis_ about the
_Flux and Reflux of the Sea_, taken from the consideration of the
_Common Center of Gravity of the Earth and Moon_; together with an
_Appendix_ of the same, containing an _Answer_ to some _Objections_,
made by severall Persons against that _Hypothesis_. Some Animadversions
of the same _Author_ upon Master _Hobs'_s late Book, _De Principiis &
Ratiocinatione Geometrarum_._

* * * * *

_An Essay of Dr. _John Wallis_, exhibiting his _Hypothesis_ about the _Flux and Reflux of the Sea_._