The said _Major_ having left that Coast, and being come to the Isle of St.
_Thomas_ under the _Line_ accompanied with four Vessels, having there adjusted his Watches, put to Sea, and sailed Westward, seven or eight hundred Leagues, without changing his course; after which, finding the Wind favourable, he steered towards the Coast of _Africk_, North-North-East. But having sailed upon that _Line_ a matter of two or three hundred Leagues, the Masters of the other Ships, under his Conduct, apprehending that they should want Water, before they could reach that Coast, did propose to him to steer their Course to the _Barbadoes_, to supply themselves with Water there. Whereupon the said Major, having called the Master and Pilots together, and caused them to produce their Journals and Calculations, it was found, that those Pilots did differ in their reckonings from that of the Major, one of them eighty Leagues, another about an hundred, and the third, more; but the Major judging by his _Pendulum-Watches_, that they were only some thirty Leagues distant from {14} the Isle of _Fuego_, which is one of the Isles of _Cape Verde_, and that they might reach it next day, and having a great confidence in the said Watches, resolved to steer their Course thither, and having given order so to do, they got the very next day about Noon a sight of the said Isle of _Fuego_, finding themselves to sail directly upon it, and so arrived at it that Afternoon, as he had said.
These Watches having been first Invented by the Excellent Monsieur _Christian Hugens_ of _Zulichem_, and fitted to go at Sea, by the Right Honourable, the Earl of _Kincardin_, both Fellows of the _Royal Society_, are now brought by a New addition to a wonderful perfection. The said Monsieur _Hugens_, having been informed of the success of the Experiment, made by _Major Holmes_, wrought to a friend at _Paris_ a Letter to this effect;
Major _Holmes_ at his return, hath made a relation concerning the usefulness of _Pendulums_, which surpa.s.seth my expectation: I did not imagine that the Watches of this first Structure would succeed so well, and I had reserved my main hopes for the New ones. But seeing that those have already served so succesfully, and that the other are yet more just and exact, I have the more reason to believe, that the Invention of _Longitudes_ will come to its perfection. In the mean time I shall tell you, that the _States_ did receive my Proposition, when I desired of them a Patent for these new Watches, and the recompense set a-part for the invention in case of success; and that without any difficulty they have granted my request, commanding me to bring one of these Watches into their a.s.sembly, to explicate unto them the Invention, and the application thereof to the _Longitudes_; which I have done to their contentment. I have this week published, that the said Watches shall be exposed to sale, together with an Information necessary to use them at Sea: and thus I have broken the Ice. The same Objection, that hath been made in your parts against the exactness of these _Pendulums_, hath also been made here; to wit, that though they should agree together, they might fail both of them, by reason that the Air at one time might be thicker, than at another. But I have answered, that this difference, if there be any, will not be at all perceived in the _Penduls_, seeing that the continuall Observations, made in Winter from day to day, until Summer, have shewed me that {15} they have alwaies agreed with the Sun. As to the Printing of the _Figure_ of my New Watch, I shall defer that yet a while: but it shall in time appear with all the Demonstrations thereof, together with a _Treatise_ of _Pendulums_, written by me some daies since, which is of a very subtile Speculation.
_The Character, lately published beyond the Seas, of an Eminent person, not long since dead at _Tholouse_, where he was a Councellor of Parliament._
It is the deservedly famous _Mounsieur de Fermat_, who was, (saith the Author of the Letter) one of the most Excellent Men of this Age, a _Genius_ so universal, and of so vast an extent, that if very knowing and learned Men had not given testimony of his extraordinary merit, what with truth can be said of him, would hardly be believed. He entertained a constant correspondence with many of the most Ill.u.s.trious Mathematicians of _Europe_, and did excel in all the parts of Mathematical Science: a Testimony whereof he hath left behind him in the following Books.
A Method for the Quadrature of _Parabola"s_ of all degrees.
A Book _De Maximis & Minimis_, which serveth not only for the determination of Problems of _Plains_ and _Solids_, but also for the invention of _Tangents_ and _Curve Lines_, and of the _Centres_ of Gravity in Solids; and likewise for Numerical Questions.
An Introduction to the Doctrine of _Plains_ and _Solids_, which is an _a.n.a.lytical_ Treatise, concerning the solution of _Plains_ and _Solids_, which has been seen (as the Advertiser affirms) before Monsieur _Des Cartes_ had publish"d any thing upon this Subject.
A Treatise _De Contactibus Sphaericis_, where he hath demonstrated in _Solids_, what Mr. _Viet_, Master of Requests, had but demonstrated in _Plains_.
Another Treatise, wherein he establisheth and demonstrateth the two Books of _Apollonius Pergaeus_, of _Plains_.
And a General Method for the dimension of _Curve Lines_, &c. Besides, having a perfect knowledge in Antiquity, he was consulted from all parts upon the difficulties that did emerg therein: he hath explained abundance of obscure places, that are {16} found in the Antients. There have been lately printed some of his Observations upon _Athenaeus_; and he that hath interpreted _Benedetto Castelli_, of the Measure of running waters, hath thence inserted in his Work a very handsome one upon an Epistle of _Synesius_, which was so difficult, that the Jesuit _Petavius_, who hath commented upon this Author, acknowledges, that he could not understand it.
He hath also made many Observations upon _Theon of Smyrne_, and upon other Antient Authors: but most part of them are not found but scattered in his Epistles, because he did not write much upon these kinds of Subjects, but to satisfie the curiosity of his friends.
All these Mathematical Works, and all these curious searches in Antiquity, did not hinder this great _Virtuoso_ from discharging the duties of his place with much a.s.siduity, and with so much ability, that he hath had the reputation of one of the greatest _Civilians_ of his Age.
But that, which is most of all surprizing to many, is, that with all that strength of understanding, which was requisite to make good these rare qualities, lately mentioned, he had so polite and delicate parts, that he composed _Latin_, _French_, and _Spanish_ Verses with the same elegancy, as if he had lived in the time of _Augustus_, and pa.s.sed the greatest part of his life at the Courts of _France_ and _Spain_.
More particulars will perhaps be mention"d of the Works of this Rare person, when all things, that he hath publish"d, shall be recovered, and when liberty shall be obtained of his Worthy Son, to impart unto the World the rest of his Writings, hitherto unpublished.
_LONDON,_
Printed with Licence, By _John Martyn_, and _James Allestry_, Printers to the _Royal-Society_.
{17}
_Num._ 2.
PHILOSOPHICAL _TRANSACTIONS._
_Munday_, _April_ 3. 1665.
The Contents.
_Extract of a Letter written from _Rome_, concerning the late _Comet_, and a _New_ one. Extract of another Letter from _Paris_, containing some Reflections on the precedent _Roman_ Letter. An Observation concerning some particulars, further considerable in the _Monster_, that was Mention"d in the first Papers of these _Philosophical Transactions_. Extract of a Letter written from _Venice_, concerning the Mines of _Mercury_ in Friuly. Some Observations, made in the ordering of _Silk-worms_. An Account of Mr. _Hooks Micrographia_, or the Physiological descriptions of _Minute Bodies_, made by _Magnifying Gla.s.ses_._
_Extract of a Letter, lately written from _Rome_, touching the late Comet, and a New one._
I Cannot enough wonder at the strange agreement of the thoughts of that acute French Gentleman, Monsieur _Auzout_, in the _Hypothesis_ of the Comets motion, with mine; and particularly, at that of the _Tables_. I have with the same method, whereby I find the motion of this Comet, easily found the Principle of that Author"s _Ephemerides_, which he then thought not fit to declare; and "tis this, that this Comet moves about the _Great Dog_, in so great a Circle, that that portion, which is {18} described, is exceeding small in respect of the whole circ.u.mference thereof, and hardly distinguishable by us from a streight line.
Concerning the New Comet you mention, I saw it on the 11. of _February_, about the 24. deg. of _Aries_, with a Northern lat.i.tude of 24. deg. 40.
min. The cloudy weather hath not yet permitted me to see it in _Andromeda_, as others affirm to have done.
_Extract of a Letter, written from _Paris_, containing some Reflections on part of the precedent _Roman_ Letter._
As to the _Hypothesis_ of _Georg. Domenico Ca.s.sini_, touching the motion of the _Comet_ about the _Great Dog_ in a Circle, whose Centre is in a streight line drawn from the Earth through the said Star, I believe it will shortly be publish"d in print, as a thought I lighted upon in discoursing with one of my Friends, who did maintain, that it turned about a Centre, because that its _Perigee_ had been over against the _Great Dog_, as I had noted in my _Ephemerides_. This particular I did long since declare to many of my acquaintance, whereof some or other will certainly do me that right, as to let the world know it by the Press. I have added an Observation, which I find not, that Signior _Ca.s.sini_ hath made, _viz._ that there was ground to think, that the _Comet_ of 1652. was the same with the present, seeing that besides the parity of the swiftness of its motion, the _Perigee_ thereof was also over against the _Great Dog_, if the Observations extant thereof, deceive not. But, to make it out, what ground I had for these thoughts, I said, that if they were true, the Comet must needs acomplish its revolution from 10. to 12. years, or thereabout. But, seeing it appears not by History, that a Comet hath been seen at those determinate distances of time, nor that over against the _Perigee_ of all the other Comets, whereof particular observations are recorded, are alwaies found Stars of the first Magnitude, or such others, as are very notable, besides other reasons, that might be alledged, I shall not pursue this speculation; but rather {19} suggest what I have taken notice of in my reflexions upon former Comets, which is, that more of them enter inter our Systeme by the sign of _Libra_ and about _Spica virginis_, than by all the other parts of the Heavens. For, both the present Comet, and many others registred in History, have entred that way, and consequently pa.s.sed out of it by the sign _Aries_, by which also many have entred.
I did found my _Hypothesis_ upon three Observations only, _viz._ those of the 22, 26, and 31. of _December_. Nor have I done, as some have fancied of me, who having been able to observe the Comet, the 27, 28, 29, 30, and 31.
of _December_, and to see the diminution of its motion, have judged, that I had only determined that diminution for the time to come, conform to the augmentation thereof in time pa.s.sed until the 29. of _December_. For _January_ 1. (on which day I composed my _Ephemerides_) I knew not (nor any person here) that the motion of the Comet did diminish; but on the contrary, most men believed, it was not the same Comet. But Signior _Ca.s.sini_ knows very well, that that was not necessary, seeing that two portions of a _Tangent_ being given, and the _Angles_ answering thereunto, "tis easie to find the position and magnitude of its Circle. The reason, which I think the true one, of the diminution of its Motion in Longitude, and of its Retrogradation, by me conjectured in my _Ephemerides_, I began to be a.s.sured of, _Febr._ 10. For until the sixth, the Comet had alwaies advanced, as Signior _Ca.s.sini_ also hath very well noted: but after that day, I found that it returned in augmenting alwaies its Lat.i.tude. And I have constantly observed it, until _March_ 8. between many Stars, which must be the same with these mentioned by _Ca.s.sini_, whereof the number was so great, that I think, I saw of them _March_ 6. with one _Aperture_ of my Gla.s.s, more than 40. or 50. and especially, above the head of _Aries_; but I did not particularly note the scituation of more than 12. or 15; amongst which I have observed the position of the Comet since _January_ 28. every day, when the weather did permit, _viz._ _January_ 29. _February_ 3, 6, 10, 17, 19, 24, 26, 27. and _March_ 6, {20} 7, 8. I left it on _March_ 8. at the 18. of the Horn of _Aries_, almost in the same lat.i.tude: and I am apt to believe, it will be Eclipsed, which I wish I may be able to observe this evening, if it be not already pa.s.sed.
If Signior _Ca.s.sini_ hath observed it on those daies that I have, he will be glad to find the conformity of our Observations. I shall only add, that on _February_ 3. we were surprized, to see the Comet again much brighter than ordinary, and with a considerable Train. Some did believe, that it approach"d again to us. But having beheld it with a _Telescope_, I soon said, that it was joyned with two small Stars, whereof one was pretty bright, which I had already seen, on _February_ 28. and 29. And this conjunction gave the _Comet_ that brightness, as it happens to most of the Stars of the fifth and sixth magnitude, where 2. or 3. or more are conjoyned, which perhaps would shew but faintly single, though by reason of their proximity to one another, they appear but one Star. Hence it was, that I a.s.sured my friends here, that the following daies we should no more see it so bright, because I knew, that there were none such small bright Stars in the way, which by my former observations I conjectured it was to move.
_An Observation imparted to the n.o.ble Mr. _Boyle_, by Mr. _David Thomas_, touching some particulars further considerable in the Monster mentioned in the first Papers of these _Philosophical Transactions_._
Upon the strictest inquiry, I find by one, that saw the Monstrous Calf and stone, within four hours after it was cut out of the Cows belly, that the Breast of the Calf was not stony (as I wrote) but that the skin of the Breast and between the Legs and of the Neck (which parts lay on the smaller end of the stone) was very much thicker, than on any other part, and that the Feet of the Calf were so parted as to be like the Claws of a Dog. The stone I have since seen; it is bigger at one end {21} than the other; of no plain _Superficies_, but full of little cavities. The stone, when broken, is full of small peble stones of an Ovall figure: its colour is gray like free-stone, but intermixt with veins of yellow and black. A part of it I have begg"d of Dr. _Haughten_ for you, which I have sent to _Oxford_, whither a more exact account will be conveyed by the same person.
_Extract of a Letter, lately written from _Venice_ by the Learned Doctor _Walter Pope_, to the Reverend Dean of _Rippon_, Doctor _John Wilkins_, concerning the Mines of Mercury in _Friuli_; and a way of producing _Wind_ by the fall of _Water_._
The mines of _Mercury_ in _Friuli_, a Territory belonging to the _Venetians_, are about a days Journey and a half distant from _Goritia_ Northwards, at a place call"d _Idria_, scituated in a Valley of the _Julian Alps_. They have been, as I am inform"d, these 160. years in the possession of the Emperor, and all the Inhabitants speak the _Sclavonian_ Tongue. In going thither, we travell"d several hours in the best Wood I ever saw before or since, being very full of _Firrs_, _Oakes_, and _Beeches_, of an extraordinary thickness, straitness, and height. The Town is built, as usually Towns in the _Alps_ are, all of wood, the Church only excepted, and another House wherein the Overseer liveth. When I was there, in _August_ last, the Valley, and the Mountains too, out of which the _Mercury_ was dug, were of as pleasant a verdure, as if it had been in the midst of Spring, which they there attribute to the moistness of the _Mercury_; how truly, I dispute not. That Mine, which we went into, the best and greatest of them all, was dedicated to Saint _Barbara_, as the other Mines are to other Saints, the depth of it was 125. paces, every pace of that Country being, as they inform"d us, more than 5 of our Feet. There are two ways down to it; the shortest perpendicular way is that, whereby they bring up the Mineral in great Buckets, and {22} by which oftentimes some of the workmen come up and down. The other, which is the usual way, is at the beginning not difficult, the descent not being much; the greatest trouble is, that in several places you cannot stand upright: but this holds not long, before you come to descend in earnest by perpendicular Ladders, where the weight of on"s body is found very sensible. At the end of each Ladder, there are boards a-cross, where we may breath a little. The Ladders, as we said, are perpendicular, but being imagined produced, do not make one Ladder, but several parallel ones. Being at the bottom, we saw no more than we saw before, only the place, whence the Mineral came. All the way down, and the bottom, where there are several lanes cut out in the Mountain, is lined and propt with great pieces of Firr-trees, as thick as they can be set. They dig the Mineral with Pick-axes, following the veins: "tis for the most part hard as a stone, but more weighty; of a Liver-colour, or that of _Crocus Metallorum_. I hope shortly to shew you some of it. There is also some soft Earth, in which you plainly see the _Mercury_ in little particles. Besides this, there are oftentimes found in the Mines round stones like Flints, of several bignesses, very like those Globes of Hair, which I have often seen in _England_, taken out of Oxes bellies. There are also several _Marcasites_ and stones, which seem to have specks of Gold in them, but upon tryal they say, they find none in them. These round stones are some of them very ponderous, and well impregnated with _Mercury_; others light, having little or none in them. The manner of getting the _Mercury_ is this: They take of the Earth, brought up in Buckets, and put it into a Sive, whose bottom is made of wires at so great a distance, that you may put your finger betwixt them: "tis carried to a stream of running water, and wash"d as long as any thing will pa.s.s through the Sive. That Earth which pa.s.seth not, is laid aside upon another heap: that which pa.s.seth, reserved in the hole, G. in Fig. 1. and taken up again by the second Man, and so on, to about ten or twelve sives proportionably less. It often happens in the first hole, where the second Man takes up his {23} Earth, that there is _Mercury_ at the bottom; but towards the farther end, where the Intervals of the wires are less, "tis found in very great proportion. The Earth laid aside is pounded, and the same operation repeated. The fine small Earth, that remains after this, and out of which they can wash no more _Mercury_, is put into Iron retorts and stopt, because it should not fall into the Receivers, to which they are luted. The fire forces the _Mercury_ into the Receivers: the Officer unluted several of them to shew us; I observed in all of them, that he first poured out perfect _Mercury_, and after that came a black dust, which being wetted with water discover"d it self to be _Mercury_, as the other was. They take the _Caput mortuum_ and pound it, and renew the operation as long as they can get any _Mercury_ out of it.
This is the way of producing the _Mercury_, they call _Ordinary_, which exceeds that, which is got by washing, in a very great proportion, as you will perceive by the account annext. All the _Mercury_ got without the use of Fire, whether by washing, or found in the Mines (for in the digging, some little particles get together, so that in some places you might take up two or three spoonfuls of pure _Mercury_) is call"d by them _Virgin Mercury_, and esteem"d above the rest. I inquir"d of the Officer what vertue that had more, than the other; he told me that making an _Amalgama_ of Gold and _Virgin Mercury_, and putting it to the fire, that _Mercury_ would carry away all the Gold with it, which common _Mercury_ would not do.
The Engins, employed in these Mines, are admirable; the Wheels, the greatest that ever I saw in my life; one would think as great as the matter would bear: all moved by the dead force of the water, brought thither in no chargeable Aqueduct from a Mountain, 3 Miles distant: the water pumpt from the bottom of the Mine by 52 pumps, 26 on a side, is contrived to move other wheels, for several other purposes.
The Labourers work for a _Julio_ a day, which is not above 6 or 7 pence, and indure not long; for, although none stay {24} underground above 6 hours; all of them in time (some later, some sooner) become _paralitick_, and dye _hectick_.
We saw there a man, who had not been in the Mines for above half a year before, so full of _Mercury_, that putting a piece of _Bra.s.s_ in his mouth, or rubbing it in his fingers, it immediately became white like Silver: I mean he did the same effect, as if he had rubb"d _Mercury_ upon it, and so paralitick, that he could not with both his hands carry a Gla.s.s, half full of Wine, to his mouth without spilling it, though he loved it too well to throw it away.