Oeuvres complètes. Tome VI. Correspondance 1666-1669
(1895)–Christiaan Huygens–
Auteursrecht onbekendNo 1547.
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at Gresham an experimentGa naar voetnoot1), explicating the inflexion of a direct motion into a curve, by a supervening attractive principle, so I may presume to guess, that your intentions of returning to London within a fortnight, were diverted by the powerful magnetism, that reigns at Lees. Those load-stones being like to maintain their vigour, I doubt you will hardly keep your resolution of coming to us next week, as your servant gave us hopes of. Mean while I shall mention to you somewhat more particularly what the experiment was, I just now alluded to, shewing, that circular motion is compounded of an endeavour by a direct motion by the tangent, and of another endeavour tending to the centre. I say then, that for that purpose, there was a pendulum fastned to the roof of the room, where we met, with a large wooden ball of lignum vitaeGa naar voetnoot2) on the end of it: and it was found, that if the impetus of the endeavour by the tangent, at the first setting out, was stronger than the endeavour to the centre, there was then generated an elliptical motion, whose longest diameter was parallel to the direct endeavour of the body in the first point of impulse; but if that impetus was weaker than the endeavour to the centre, there was generated such an ellipsis, whose shorter diameter was parallel to the direct endeavour of the body in the first point of impulse: and if they were both equal, there was made a perfect circular motion. After this there was made this other experiment. Another smaller pendulous body was fastned by a shorter string, on the lower part of the wire, which the greater ball was suspended by, that it might freely make a circular or elliptical motion round about the bigger, whilst the bigger moved circularly or elliptically about another centre. The intention whereof was, to explicate (infavour of Dr. Wallis's HypothesisGa naar voetnoot3) about the flux and reflux of the sea, which has been pretty well sifted among us) the manner of the moon's motion about the earth, it evidently appearing thereby, that neither the bigger ball, which represented the earth, nor the less, which represented the moon, were moved in so perfect a circle or ellipsis, as otherwise they would have moved, if either of them had been suspended and moved singly; but that a certain point, which seemed to be the centre of gravity of those two bodies, howsoever posited (considered as one) seemed to be regularly moved in such a circle or ellipsis; the two balls having other peculiar motions in small epicycles about the said point. This latter experiment I imparted to Dr. Wallis, who is, as I found by his answer, very well pleased with it; and hopes withall, that that theory of his will answer all the main phaenomena of the tides; though he pretends not, to give thereby a satisfactory account of the particular varieties of them in several places of the world, for want of a full history of the same. | |
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Sir Th. de VauxGa naar voetnoot4), at the same meeting, presented the company with a bundle of considerable papers touching coloration, drawn up by a very famous and curious physician, from the mouth of the most knowing and experienced dyers of England and Holland in his time; the Society ordered there upon a committeeGa naar voetnoot5), to consider of these papers, and to distribute them among themselves to be Englished, they being almost all in French, and then to digest them: which being done, I am persuaded, that many notable particulars will be there met with, to illustrate the philosophy of dying, &c. There was also, at the same time, brought in a discourse by Sir Gilbert TalbotGa naar voetnoot6), of a rare stone, to be found in Sweden yielding four different substances, viz. sulphur, vitriol, alum, and minium; of which the presenter was desired to procure us a good quantity for trial, which he promised to do. Monsieur Auzout was then elected into the Society, nemine contradicente; and a diploma is to be dispatched to him, as was done to Monsieur HeveliusGa naar voetnoot7). The same, I find by my last from Paris, is nominated for one of those choice persons, that are to constitute their academy; some of the rest, that are pitched upon, being Monsieur Roberval, Monsieur Carchavy, Monsieur Frenicle, Monsieur PicardGa naar voetnoot8), Monsieur Huygens, all very able men, appointed to meet and to consider of the best way of framing a philosophical Society, and the best method of carrying on its designs. I perceive, they will chiefly pursue mechanical and chemical experiments, they having already in their eye a coople of good chemistsGa naar voetnoot9), and some able mechanicks, that shall work by their directions. On fera faire (saith my author) tout ce qu'il faudra pour travailler utilement. On à desia commencé de s'assembler pour faire quelques | |
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reglemensGa naar voetnoot10). C'est un beau et grand dessein, qui ne peut estre qu'utile et glorieux, à la France. He adds, on pourroit faire aussi quelque chose en Denmark, parce qu'il s'y trouve des sujets capables et tres intelligens. Indeed they have some there, that are very learned men, as Erasmus Bartholin the mathematician, Thomas Bartholin the physician, and Steno the anatomist; the last of which has been, I find, much courted in France, and is now so in Italy at Florence. I hope our Society will in time ferment all Europe at least: I wish only, we had a little more zeal, and a great deal more assistance, to do our work thoroughly, as I am apt to believe the French will study to do theirs (they being like to be endowed), were it but out of emulation. So good be done to our generation, and a ground laid to do the like to posterity, no great matter what passions do concur for the performance. The Venetian embassador JustinianiGa naar voetnoot11), now at Paris, hath sent me, by the hands of my correspondent there, a considerable printed paperGa naar voetnoot12), (for the Society)Ga naar voetnoot13) published in Italy by Signor Cassini, containing many notable observations, made in February, March and April last, with some of Campani's glasses, touching the conversion of Mars about his axis, performed (as he affirms to be assured of by very good observations) in the space of twenty four hours, forty minutes. You remember, Sir, that the same was observedGa naar voetnoot14) here in England in the same months, witness one of our Transactions, number 11.Ga naar voetnoot15), which I am now very glad took timely notice of it in publick. Dr. Beale presents you his hearty service: is very busy upon some new subject; commends Parker'sGa naar voetnoot16) Censure of the Platonick PhilosophyGa naar voetnoot17) and thinks, that the same arms against Glanvil's Pre-existence of soulsGa naar voetnoot18). Monsieur Glan- | |
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vilGa naar voetnoot19) is, I find, of an excellent temper for argument, and I believe, that he will rather yield and fly the field, than handle a weapon unhandsomly. I presume to swell this letter with this month's Transactions. If Essex breeds curiosity, those papers may be made known there by your influence; and the chief place of the concourse of the gentry there being intimated to the printers of them, they may monthly send them thither, as they do to many other parts of England. I need not, I suppose, entertain you with the relation of the late rude, and obstinate fightGa naar voetnoot20), or the success thereof. I shall only say this of it, that as the engagement will not easily be paralleled, so we shall find the success, all things considered, a great deliverance and a dear victory to us. Mean while, God be thanked, both our generalsGa naar voetnoot21) are well, having done prodigious things, and the king in a condition to set out very speedily another fleet; which that it may be done so, as to prevent our enemies, is of the highest concernment in this business. We know not where the French fleet is: some say, turned back to Cadiz; others in their way to come about the north of Scotland, to join the Dutch, and to make them appear again presently. My last letter from Paris hath only this; Les Suedois pourront bien estre mediateurs et arbitres de la paix. La France obligera la Hollande de leur donner satisfaction, et de renoncer au traitté d' ElbingGa naar voetnoot22). But I am tired, it being past midnight, and I believe, you have cause to be so much more at the rhapsody of,
Sir, Your very humble, and faithfull servant Henry Oldenburg. |
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