Cartes valued the History of Nature as much as any experimental Philosopher ever did and perfected it more with judicious experiments then ye will by all appearance do in ten ages Ye are exceedingly misinformed if ye have heard that any here have prejudice or envy against you for there is none here speaks of you but with pity and commiseration neither heard I ever of any man who commended you for what he understood As for your Latin Sentences if they be not applyed to your self I understand them not for here we are printing no Books we are not sending tickets through the Countrey to tell the wonders we can do We are going about the imployments we are called to and strive to give a reason for what we say Where then are our doli fallaciae tabulae testes sapientia ad quam putamus nos pervenisse c. In these things ye publish ye know there is no Sophistry but clear evidence If ye had done such great matters in Universale ens rationis ye might have had a shift but here ye must either particularize your inventions or otherwise demonstrat your self derogatory to the credit of the Nation For what else is it to confound R. Societies and Universities with an Ars magna nova and yet when ye were put to it in print to show your inventions all ye could say was that the publisher should have reflected upon the wisdom of the Creator c. so that the Poet said well of Democrites c. of which I understand not the sense except ye make your self the summus vir and us all the Verveces I suppose this may be the great credit that ye say ye have labored to gain to your Nation to wit to get us all the hornable title of Wedders No more at present but hoping this free and ingenuous Letter shal have a good effect upon you for I am half perswaded that the flattery of scorners and ignorants hath brought you to this height of imaginary learning and that when ye come to your self ye will thank me for my pains I rest Your humble servant After this I had no notice of him or his Book until a copy of it came to my hands which when I had opened it I found dedicat to a Noble Person whose very name being there did creat in me a greater respect for the Book then I thought my self capable of for any of the Authors works and made me fear some finer things in this then any other of his Books would suffer me to expect For having known his Lordship an ornament to this Place when his Vertue was but in blossom I have easily given credit to that universal testimony which reports him to have gained to himself an high esteem among Strangers by those excellencies which are the glory of his Family and Name and therefore I could not but apprehend this present offered to his Lordship on so solemn a day to be something extraordinar But having read over his Theorems I admired the presumptuous arrogance of the Author in concerning the authority of so Noble a Name in so worthless a trifflle And having returned to the Dedication to see what he said for himself I justified his first application for Pardon that he had prefixed his Lordships Name to the bastle and abuse of a Noble subject Then I considered the motives of the Dedication and found them great yea so great that I wonder they did not fright him from so daring an attempt For his Lordship I hope hath not given security to Strangers abroad that he might draw upon himself injury from his Countrey-men at home his vertues have not made an Italian shelter under his Patrociny that this bold Scribler might be encouraged to send his Lordship through the world as a Protector of falshood and countenancer of such as cannot handle truth without corrupting and defiling it Could not his Lordships Heroick vertues and understanding mind could not the learning and other excellent endowments of his Lordships Father Grand-father and Great-Grand-father could not the Dignity of their famous Ancestors and the Antiquity of their Illustrious Family preserve him from the importunity of this impudent man who will needs enlighten his dark ignorance with the splendor of his Lordships Name Was not his Lordships being an encouragement to learning sufficient to have kept this arrogant pretender there o from soliciting his Lordships authority to his folly and infirmity Surely when he adressed this Book he either little considered his Lordships abilities to judge thereof or else he intended to court his friendship and affection for a defence against the power of his understanding if he gain his design he hath reason to say that his Lordships goodness is proportioned to his other accomplishments After this view of the Dedication I went through the rest of the Book unto the Postscript where I find mention made of the Letter which I sent to the Author who was wiser then to print it lest thereby he had published his own shame but he lets it not pass without a cast of his craft For finding that by it his ignorance is discovered he foams and rages he is troubled in spirit because he is disturbed in the exercise of his Art that is because he is not permitted to call other mens truths his own and his own falshoods and follies rare and useful truths and obtrude them upon the world as such and being fettered with that reason which opposeth him he in the bitterness of his spirit vomits out his spight against her calling her Sophistry Non-sense and whatever his anger suggests to him and breathing nothing but revenge he calls together his choisest vertues Fury Malice and Boldness and having got them to joyn with his Ignorance he endeavors by these united forces to uphold his cause Nor was any of them wanting to him as may appear from their particular atchievements which are remarkable in that review of my Letter which summeth up his Postscript and in sum equally betrayes his Insufficiency and Insincerity For therein he treateth the Masters of this Vniversity so unworthily as he had done in the second Letter of his Postscript in answer to that Gentle-man who by direction wrote unto him their mind that I know nothing like it except the spirit of its Author and that entertainment which he in the Preface to his Ars magna and pag. 472. gives to the late Arch-Bishop of Glasgow who had been most kind to him and Masters of the Colledge there in which some then were yet are who may be his teachers in any thing he pretends to But this Postscript doth not sufficiently discover the Authors vortues and therefore he spends a part of his first Epistle to the Reader in such flat and vulgar railings as prove him fitter for nothing then to hold the principality among the Street-scolders And moreover that the provocation may be compleat he gives a formal appeal to any who dare state
Refraction and therefore impertinently repeated It is no wonder the Lord Verulam was not of my mind for he died before the time of Des Cartes who brought the Opticks to this perfection But it is no smal wonder to find a man pretending so highly to learning as our Author doth and yet print himself a stranger to the progress thereof It is true indeed that M. Newtown hath discovered an inconvenience in Refractions which was not formerly known and that therefore Metallin Mirrours are more proper then glasses but this hath not added any thing to that universal rule I presently mentioned which scientifically bringeth the sight to any degree of perfection and holdeth in these Telescops as well as in all others yea these Telescops were known before only their advantage above others was not known What he saith of M. Hook is most improper seeing there he only promiseth to accomplish or bring to practise what hitherto hath been attempted or by all most desired not at all mentioning the Science which our Author questions Let any man consider the vast extent of that rule and think what can be more large I do not question that there may be many excellent and subtil inventions for promoting sight as to practise but I am sure the scientifick part cannot make the sight infinitly perfect and it hath already brought it to any degree of finit perfection He flatters himself that he hath gained the victory as to the Hydrostaticks but upon what account may be seen in my Letter which being written in privat only for disswading him from making himself ridiculous and for curing him of his blind presumption was framed to his capacity and not for the learned world And seing it was necessar because of the importunity of his Letters to signifie to him that this Science was already perfected as to all these things whereof he is capable it was more civily and respectfully spoken to say that the Hydrostaticks were already perfected then to say that they were further perfected then he could reach Our Author should know that all mixed Mathematical Sciences are nothing else but Geometrical Demonstrations founded upon some Physical Experiment So that Geometry to speak properly is the only Science in Mathematicks and their only store-house for rules methods reasons and inventions It is certainly defective in several things but these are far above our Authors conception He next strives to perswade the unlearned that he hath first taught Astronomers the use of Telescops and Pendulum clocks but I leave this to the examination of his experiments Yet I must not pass that which he desires the Reader to mark to wit my non-sense in saying That the invention of representing the Sun or Moons motion in a second of time had been greater if the eye had been away And I intreat the Reader to mark as well how M. Sinclars dulness maketh him impute his own non-sense to me for in his printed Letter Feb. 22. he challenged as a great neglect that the Eye is not added in an expression of a former Letter as if any could have dreamed that the observation might be without the eye to which I answered That the invention had been greater if the eye had been away and surely so it had Nor could this have escaped M. Sinclar if he had not wanted his eyes but his blindness hath made him stumble upon my expression and because he could not bruise it with his fall he hath lashed me for his own fault Surely this discipline is very near in kind to his doctrine for they are both unreasonable I have nothing to say against his miracles in the West especially that grand one of the Sun seen in Winter for an hour about midnight eight degrees above the Horizon except that it is only mentioned in his Book no man I ever spoke to having heard of it altho I know many who have been in the place mentioned and very inquisitive concerning it Besides that laying one aside it far surpasseth all miracles of the heavenly bodies recorded in facred History If our Author think that he was well exercised when he was making his observations of the Comet he should judge a part of his time well spent in letting the world know for what they served but he seems to intend no more then to make men believe that he is not ignorant of a degree or a minut altho he reckons the Suns motion by inches I question not that a Coal-hewer is more useful to the Countrey then he and I both and therefore he is obliged to me for giving him a more useful trade then he now driveth Nor can I deny but he justly deserved it for a Coal-hewer is one who maketh gain by digging in another man 's mine and so hath he done for that History of Coal which he hath printed is none of his altho he hath made advantage by the publishing and sale thereof But this is no great wonder since the most part of the truths contained in his writings are digged out of other mens works And that the Author of this History may not escape the fate of others with whom he maketh so bold he mixeth with his doctrine some mistakes of his own and particularly that erroneous application of Euclid above mentioned in page 4. of this Book Now my Lords and Gentle-men who are Coal-masters I pray you consider how unjustly M. Sinclar inferrs that I design for you no better name then I have given to him and how maliciously he thereby endevours to creat in you a prejudice against me I highly esteem and honour all such whose knowledge and vertue maketh useful and ornaments to their Countrey But pardon me that I suffer not M. Sinclar to usurp to himself the name of a Philosopher for writing this History altho it were his own since he wants the Science of Coal for it is not History but Science that makes the Philosopher I need not concern my self much in his censure of Des Cartes for he is as far exalted above my commendation as he is without the reach of M. Sinclars detracting tongue He may well say that he is not afraid I shal come the length of his labours in Glasgow Colledge about Vniversale and Ens-rationis for in his last Logick Notes he hath thirty sheets of paper upon Genus and Objectum Logicae Vniversale and the Praedicables which falsifies the first sentence of the Epistle to the Reader of his Ars Magna He might have holden his peace of Rhetorical and Algebraical composition and resolution for he knows no more of either but the name If he had read this part of my Letter right he would have had some other fansies then he here expresseth as I should show were not this too sheepish a subject to be insisted upon It is true that a Letter was sent to M. Sinclar containing the words which he printeth but it is as true that the same Letter contained the condition of that promise which he there
THE GREAT AND NEW ART OF WEIGHING VANITY OR A Discovery of the Ignorance and Arrogance of the great and new Artist in his Pseudo-Philosophical Writings By M. Patrick Mathers Arch-Bedal to the Vniversity of S. Andrews To which are annexed some Tentamina dâ— motu penduli projectorum GLASGOW By ROBERT SANDERS Printer to the City and University 1672. THE PREFACE TO THE READER READER I doubt not but thou art surprised to find me in print and I assure you that it is not more above your hope and expectation then it is contrair to my former designs and resolutions But as Atis his dumbness from the womb could not keep him from brusting into speech against those souldiers whom he saw ready to have killed his father so my general insufficiency in all things else cannot keep my natural affection in longer silence when I see my bountiful Mother this ancient and famous University and all her beautiful Daughters the other Universities of this Kingdom in hazard to be murdered by one of their unnatural children And finding that he with whom I have to do hath given but a very lame and partial account of the occasion of our debate I judge it both thy interest and mine that I correct it by a more full perfect and impartial one For as â—he Magicians feigned miracles found greater belief with the Egyptians then the true ones of Moses so a false information having nothing to contradict it oft times prevails as true with us Thus then it is My adversary having published his Tyrocinia Math. and his Ars. Magna Nova c. one here who well understands those things intending to oblige the Author and redeem his Countrey from further injury by his writings friendly represented to him some of his failings in them And another whose judgement he ought to have esteemed much with the same intention expressed to one of his nearest friends his dislike of those Books and his regrate for the loss which the Author put himself and his Countrey to by them But this was not sufficient to convince him of his weakness for he proceeds to give the world another instance of his folly in printing his Hydrostaticks and notwithstanding what had past he yet fancies that the Masters of this University have as high an esteem of his sufficiency as he himself And therefore not doubting of their encouragement to so noble a work he confidently fends his petitory letters to some of them intreating their own concurrence and their assistunce for procuring the encouragement of others thereto With his Letters he sent this following Edict Forasmuch as there is a Book of Natural and Experimental Philosophy in English to be printed within these four moneths or thereabout Wherein are contained many excellent and new purposes As first Thirty Theorems the most part whereof were never so much as heard of before in which are proposed briefly the chiefest and most useful principles of that new Doctrine anent the wonderful weight force and pressure of the water in its own Element There are next twenty Experiments in order to that Doctrine not only most pleasant and most easie to all capacities but most useful likewise which are set down after this method First each particular Experiment is briefly and clearly described by its own distinct Schematism and Figure Secondly the curious Operations and natural effects of it are shewed Thirdly the true causes of these natural effects are searched into and most evidently explicated and demonstrated not only by the force of reason but by the evidence of sense also And lastly at the close of each Experiment you will find most naturally deduced from the preceeding Demonstrations many excellent and new Conclusions hitherto unknown and these for the advancement of natural knowledge and practice among which mention is made of a new and more commodious way of Dyving After all which there is a number of Miscellany Observations some whereof are Experiments made in Coal-sincks for knowing the power of Damps and ill Air by killing of Animals Some made for knowing the variation of the Compass here and an excellent way for knowing by the eye the Sun or Moons motion in a second of time which is the 3600. part of an hour and many others of different kinds useful and pleasant These are therefore to give notice to all ingenious Persons who are lovers of Learning that if they shal be pleased to advance to Gedeon Shaw Stationer at the foot of the Ladies steps three pound Scots for defraying the present charges of the said Book they shal have from him betwixt the date hereof and April next to come one of the Copies And for their further security in the interim the Authors obligation for performing the same Edinburgh the 14. of December 1671. Which so exposed to my Masters the vanity of that confident man that they were forced plainly to let him know their mind as is expressed in the first Letter of his Postscript To this he returned an answer which though it as little deserved his superlative commendation as their censure was abundantly discreet for obliging them to silence until his Book should come to light But to show how contrair to his nature this was it quickly repented him of his discretion and a little after without any such provocation as he alledges he alarmed this place with a flood of his fury whereof he dischargeth himself in the second letter of his Postscript My Masters thought it unworthy of them to give any reply to this lest by engaging themselves in a debate with one who had nothing wherewith to entertain them except railing and calumnies they had stained their reputation and gained to themselves nothing but the name of foolish persons for speaking to a fool in his folly but I to be ingenuous having no much greater reputation for learning then himself was content to hazard it against him and knowing well his bragging humor to be such as would make him insult and erect Trophies if nothing were replyed I sent to him a Letter which to my best remembrance was in the words following Sir I admire exâ—eedingly the forwardness of your humor I will call it no worse in your last to he is a person not concerned in you or in your books neither will he ignorantly commend any thing as it seems ye expected he should have done when ye sent him these papers Ye might have known long ago that he had no veneration for what ye had formerly published for he made no secret of his mind when he was put to it Ye may mistake him if ye think that any by-end will cause him speak what he thinks not nevertheless he delivered your commission and was willing to be inconcerned expecting their answer They pressed him to know his judgement of your last piece he told ingenuously the truth that there was none of them had less esteem for it then himself He hopes ye are so much a Christian that ye will not be offended
himself his adversary and makes such ostentation of his strength and courage that rather then want a combatant he will purchase one with gold for he offers a Guiny for every Theorem which shal be everted either in this or his last Book And such is his generosity that I cannot doubt but he will also be as noble in requiting the labor of any who shal give him some Tyrocinia whereby he may correct his discovered errours Sure I am there may be as much gained here as would tempt my Adversary once again to blot a great many sheets of paper if to boot he could be assured of a Crown or Rix-dolar or rather then lose his market a Legged-dolar for every Book that should stand himself no more then two Merks Now Reader I am confident thou thinks me further engaged after all these provocations then that I can retreat with honour and so think I my self And therefore I have accepted my Adversaries Challenge I have examined all his Books I have weighed them in the ballance of reason and have found them so light that they deserve no better name then Vanity I have displayed the Authors infirmity and folly in every one of them without other design then to protect my Countrey and particularly all such as he endeavours to concern in his Writings from the mean thoughts and misapprehensions of those who have no other character of both then they receive from them Yet in this Review I have not displayed all the enormities of this Arrogant pretender to Knowledge for this should have made my Book swel as far above a just measure as his Arrogance and Insolence is above every thing except his Ignorance seeing every period of his Writings is either pregnant with falshood or if it contain a truth which he hath taken from some other his probation thereof is either from false principles or management so silly and childish as makes it appear ridiculous Neither have I taken notice of all the impertinencies whereof he is guilty lest thereby I had hazarded the reputation of my good nature But I have only exposed some of his grosser failings to let the world know that he hath not so much wit as himself presumes and discovered his inveterat malice to undeceive those who think him a man of much sincerity And this I have done with so much evidence and demonstration that I fear not thy censure if thou be intelligent Not have I sent this book to your hands under any other Patricony then that of Reason for she is able to recōmend it to the favour of my Friends and protect it from the Fury and Malice of my enemies But if it were not that the meanness of my person and station should have made my adress as indecent as the naughtiness of my Adversaries Present made his I would have offered it as a testimony of my humble duty and sincere respect to that Noble Person to whom he hath dedicat his Hydrostaticks and as earnestly have solicited hisVnderstanding to judge of my Truths as my Adversary hath done his Lordships Friendship to accept his Favour to protect and his Name and Authority to convoy his Falshoods through the world Nor should I either have precipitated or suspended my adress for finding so craving an opportunity as the day of his Lordships Birth and Majority From my Chamber in S. Andrews the 24. day of July 1672. THE GREAT AND NEW ART OF WEIGHING VANITY AS in combating each party first intends his own defence and in the second place only prepares an assault for his Antagonist So I before I make any attempt on my Adversaries other Writings shal endeavour to wipe off that durt which he hath thrown upon me in the Postscript and Preface to his Hydrostatics I think it no wonder that my Adversary hath suppressed that Letter of mine which he mentioneth in his Postscript and I have printed in my Preface for this gives him the greater liberty to belie it which he doth most splendidly when he saith that it is full of barbarous railings passing all bounds of civility against himself friends and works whereas there is not a word of his friends in it and what is therein said of his Works the following Treatise will manifest if it deserve the name of barbarous railings Nor is it strange to see one who wants truth on his side make lies his refuge But he may henceforth look for the common infelicity of liars not to be believed if he shal chance to stumble upon truth I had reason to fall upon his Ars magna c. because I judge ex ungue Leonem or rather ex cauda Catum Nor should the bare title have been past by because it is arrogant and false as shal be made to appear in its own place I am unjustly in this compared to blind Vejento for he had the beast but at one hand but to whatever hand I turn me I find the beast there And because my Adversary complains that I have only snarled at the horse heels I shal henceforth endeavour to pull the Ass from the sadle I excuse my Adversary for not interpreting his Latin verses because they were sent him from without interpretation I am obliged to his esteem in supposing me a Master in an Vniversity He was never judged worthy of that dignity here and by his ingratitude to Glasgow he hath proven himself unworthy ever to have had it there or any where else And I wonder that judging me a Master here he should think strange that I am not so Pedantick as in imitation of him to stuff my Letter with Latin Sentences altogether impertinent to our debate and which in his Letter and his review of mine serve for nothing so much as to express his malice and virulency Yea there be two things which I think more then strange inconsideratness in him The first is that he accuseth me for not writing pertinent language in my Mother tongue whereas in the very next page he writes He hath done as the Ape did that thrust the Cats foot into the fire because he durst not do it himself whereof if he or make good sense and Grammar I shal give him back one of those Guinies which I am to have for everting his Theorems The other is that he should challenge an Vniversity-man for writing a Letter without a Latin Sentence whereas he hath written Volums of Mathematicks without ever for any thing I have yet seen citing a Classick Mathematician except once Euclid Prop. 24. lib. 1. El. Geom. in the 265. page of his Hydrostaticks and that erroneously For Euclid hath two sides in one triangle equal to two in another and our Author hath only one side in each triangle This is like the Tarsel of a Mathematician I had reason to ask Where are our doli fallaciae tabulae testes sapientia ad quam putamus nos pervenisse For first none here being further concerned then in answering his importunat Letter
mentioneth to wit If he made it appear that his Book were answerable to his Edict The concealing of this is so great a proof of his candour and ingenuity that infallibly it will procure credit to any thing he affirms Now this Good Man having spent many of his spirits in this tempestuous conflict is opprest with drowsiness and having fallen asleep he dreams all the rest of his Postscript For I am sure there is not one in this Vniversity who ever either had his name in an Almanack or craved any man pardon upon such an account I have seen the Pamphlet he speaks of with the Advertisement to the Reader and found nothing in it of any ingenious Gentleman Artist set upon inhumanely as by two Mastives but some Printer checked for playing the Astronomer unhandsomly and that under a borrowed name for to make his Prognostication the more vendible a practise too ordinar Our Author here talking of two judgeth this business to be of the same difficulty with that of D. Mores butter Scon which could not be sufficiently fenced from the violence of the Air by less then the Syllogistical force of two bold brethren However if there be any errours in that Almanack he bewrays his ignorance in passing them while he lets a fling at the mistake of a Table and at some Chronological Rhymes things of no importance For the first it may be imputed to a piece of rashness occasioned perhaps by the obscurity of that Tables explication but not to ignorance seeing such triffles as Tobacco-boxtables and Pocket instruments which produce nothing but what can be better done without them conduce not to knowledge And therefore no reproach for a man to be ignorant of them being contrived only for Mechanicks and such sensible Demonstrators as my Adversary is As for the Rhymes I suppose there is as little necessity of thinking the Author of them and of the Almanack to be the same as of judging the new and unheard-of Hydrostatical Theorems and the bundle of Latin Sentences in the reply to my Letter to have been tursed by the same hand I have no regard for Rhymes and yet for recreation I must take notice of our Authors two Criticisms whereof one is the two last lines exceed the former in a foot contrare to that of Horace Primum ne medio c. Consult our English Poëts Sir what weight this authority hath with them The other is It should not have been said Since that of nought the Lord created man But Since that of dust c. Pray you Sir is this sound Philosophy and if it be how taught you your Scholars Cap. 7. de Causalitatib Caus Prim. Creatio est actio causae primae quâres primo ex nihilo producuntur But who then can this Prognosticor be It is very probable from the rable of Astrology for there is none of that profession among us that he is my Antagonists Apocalyptical Astrologue who Lib. 6. Dial. Phys 3. Sect. 1. besides his Astrological Predictions and Prophesies out of the Old Testament did from the Revelation of S. John with great zeal declare many and these even wonderful things concerning the number of the Beast 666. and the Alphabetical letters A. B. I. S. of great affinity with it The mystery of these must not be revealed lest it occasion the discovery of that divine Astrologue There is little heat here about Ens rationis that crack-brain'd knave hath evanished together with his Cousin-germain M. Sinclars dearly beloved Forma substantialis materialis For ought I know they have got in to his Nihil spatiale to erect a Colledge of Fanatick Philosophers I Am now to examine his Epistle to the Reader where he complaineth exceedingly of Envy because the Masters of this Vniversity would not take his word for the novelty of his inventions Nevertheless he must grant if he will be ingenuous that they have done him a courtesie in causing him prefix a more modest Title to his Book then his Edict carryes He wrongs M. Boyl egregiously in causing him say generally that Archimedes's Demonstrations have more of Geometrical subtility then usefulness whereas he saith only in the Preface to his Hydrostatical Paradoxes that many of his Hydrostatical Propositions have more of Geometrical subtility then usefulness It were non-sense to speak so of Demonstrations seeing their only use is to prove the thing in question which if they do they cannot be called useless and if they do it not they cannot be called Demonstrations Our Author now compares his method with that of Archimedes's forsooth He is more speculative our Author is more practical So may a Trone-lord say Archimedes was more speculative in his Staticks and he more practical Next Archimedes's Demonstrations are Geometrical and his Physical That is to say Archimedes's reasons are sure and solid and his are conjectures And then Archimedes's Demonstrations are but for the use of a few and these for the use of all He might truly have added And for all uses except to convince which is the proper use of a Demonstration As for his last comparison Archimedes was more wise then to illustrat that in his Book which any mean man might do and was already demonstrated But our Author needs not imagine that a rational man will venture any surprising Demonstration to the world without practising it if he can yet there was no necessity that he should swel his Book with it I say the like of Stevinus in whose Demonstrations I am not afraid our Philosopher show any defect nevertheless that he be pleased to speak at random He beginneth now to tell the strange things he hath invented And first he saith that he considereth the pressure of the water with the pressure of the air joyntly Can our Author be so ignorant that he knows not the arise of the Toricellian experiment Was it not from the consideration of Pumps and other Hydrostatical machines that they had no effect above 33. or 34. foot Was it not considered here by Galilaeus that water pressed water no further then its own level and it was probable the weight of the Air might press it up the rest of the way seeing it was not much which it ascended in the Pump Upon this account he projected the experiment first in water where was considered the pressure of Water and Air joyntly and afterwards Toricellius perfected it in Quick-silver judging rationally that the great weight of the fluid by shortning the tube would facilitat the experiment In M. Boyls continuation of Physico-Mechanical Experiments Exper. 13. 14. 15. Doth he not consider the pressure of both together Yea is there any intelligent man who now speaks of a Pump or any Hydrostatical engine without considering both these pressures together All these counterposings which he speaks of have been tryed by M. Boyl and also many more to wit oyl of Turpentine and oyl of Tartar c. but if our Author please he may try it yet with Ale Beer Urine
c. and all these shal be new Experiments He should have been more general in these tryals and more particular in the mysteries and secrets of the Art which he hath discovered and none else can get notice of Archimedes asserts the weights of all fluids in general and consequently of the Air if it be a fluid which the Learned never yet denyed Yea Archimedes's Cōmentator Rivaltus who died long before the Toricellian experiment mentioneth the Air and its weight That assertion of M. Boyl is true at present and will constantly be so suppose every man alive print such Volums as our Author hath done However the learned Doctor Wallace hath published a Book not long ago notwithstanding all our Authors invention in which he deduceth more then ever our Author shal know of the Hydrostaticks as consectaries from one proposition Now Reader I stay no longer here to consider my Adversaries indiscreet railings and provocations for this were unworthy both of you and me But that you may know that I am a man of my word I proceed to the survey of his works as I promised in my Preface And I am not a little incouraged to this by the hope of gaining as many Guinies as may help that pitiful poverty wherewith he upbraideth me But lest he think that the Probleme which his Brother proposeth concerning the bringing up from the bottom of the Sea any weight that can be sunk therein hath bougled me I think fit to give thee here three several answers thereto First then for effectuating that which is there proposed you shal take the new invention called The Dyving Ark one so large that it requires a greater weight to sink it down then the Pondera demersa which being sunk down near to the Pondera demersa the Dyver must first bind them to the Dyving Ark and then loose away the weight which did sink it Now the Pondera demersa being ex hypothesi lighter then the weight which was sufficient to keep the Ark at the bottom must of necessity be pressed up with the Ark by the water and the nearer it cometh to the brim the motion will be the swifter not only for the acceleration of the motion but also because the Air dilateth it self and as I determinat in my Examination of this dyvink Ark the Ark is pressed upward with as much force as the quantity of water equaling the included Air would cause by its weight in the Air. But if the Inventer will take my word upon it his Ark must be stronger then a Wine glass and without holes in the bottom nay it must not have a Glass window of a foot in square at least not near the bottom And if the Pondera demersa be great when he hath done his utmost in case the bottom of the new Invention get out you may have supply from the old Hydrostaticks Thus You shal take at a low water some great strong tuns banded with iron so many of them that being all full of water they are heavier then the Pondera demersa in the water that is to say that the weight of all these tuns full of water may weigh more then the Pondera demersa having rebated from their weight the weight of their quantity of water These tuns being all emptied and exactly closed and iron chains or strong ropes tyed to their iron bands let the Dyver go down in his Bell and bind these chains or ropes all the tuns may be fastened to one chain to the Pondera demersa as near as may be and the rising water shal lift the Pondera demersa from the ground which being once done they are easily drawn any where If the Pondera strike on the ground at the next low water stent the chains as much as ye can I suppose any man who tryeth these ways will be best pleased with this which hath been known these many ages seeing it is far easier to multiply tuns then to make a vast bulk of an Ark with a bottom proportionably strong to resist the pressure of the water and to be troubled with a weight sufficient to demerge the same These two Answers I have got from my two brethren the inferior Bedals who are as fertil in affording satisfactory answers as my Adversaries Brother is in starting subtil questions If it be objected against the last of these two Methods that it can only be practised where the sea ebbeth and floweth I give you a third Take two ships any of which is sufficient to raise the Pondera demersa the one deep loadned with stones or any such thing the other altogether empty Bind the loadned ship as near as may be to the Pondera demersa which may be easily done by the help of the Dyving Bell and then liver her into the other which was empty This livered ship shal raise the Pondera demersa from the ground which afterwards may be easily drawn any where And if perchance they strike on the ground in the drawing let them be bound again to the new loadned vessel doing as formerly This method I suppose you will find in Vitruvius who is a very old Writer and yet if M. Sinclar had given it it is like he would have listed it amongst his new Inventions as he did Riccioli's erroneous argument against the motion of the Earth Hitherto I have been employed in parreing those thrusts which M. Sinclar gives in at me through all the Postscript part of the Preface to his Hydrostaticks It is now high time for me to prepare an assault for him this being a part of my Province and in forming it I shal make use of no weapon but Reason hoping from it better success then my Adversary hath had the rather because he is so great a stranger to it The first shal be upon his Hydrostaticks because that began the debate The second upon his Ars nova magna because of the reproaches my Masters have sustained for their just censure of it And the last assault shal be upon his Tyrocinia which indeed is more blameless then the rest being freest from errours and more consonant to its title yet albeit it had no name prefixed it could not but sufficiently discover the Tyro and the Great and New Artist to be all one All this shal be done in the proper language of each Book that every work its examination may be understood by the same Reader And so I begin with the Hydrostaticks AN EXAMINATION OF M. SINCLAR'S Hydrostaticks Non equidem hoc fludeo bullatis ut mea nugi◠Pagina turgescat dare pondus idonea fumo Secreti loquimur Pers THat I had sufficient reason to quarrel the offer of thirty new and unheard-of Hydrostatical Theorems shal appear from the examination of this Treatise whereof all that is true for a considerable part of it is false and ridiculous is the same with the doctrine of Archimedes and Stevinus in the following Propositions only our Authors doctrine is more loose
and less precise As for what he hath written concerning the Bensil of fluids generally applyed is false seing no Bensil hath hitherto been perceived in any fluid except Air. And seing the doctrine of the spring of the Air is called by most of Authors and particularly by M. Sinclar himself Aërostaticks I think not my self obliged to reduce it to the writings of Archimedes and Stevinus who wrote only Hydrostaticks properly so called yet in that subject also where he speaks truth I shal in its due place trace him in Aërostatical Writers extant before him In the review of this Tractat I shal for my hires sake begin with the Theorems and afterward take notice of a few things in the Observations and Experiments §. 1. The Theorems reviewed whereof a great part are proven false others ridiculous and the rest not new I Shal here at once discover the falsity and ridiculousness of a considerable part of our Authors Theorems and reduce the rest to these following Propositions of Archimedes and Stevinus Archimedis Positio 1. Ponatur humidi eam esse naturam ut partibus ipsius aequaliter jacentibus continuatis inter sese minus pressa à magis pressa expellatur Vnaquaeque autem pars ejus premitur humido supra ipsam existente ad perpendiculum si humidum sit descendens in aliquo aut ab alio aliquo pressum Prop. 2. Omnis humidi consistentis atque manentis superficies Sphaerica est cujus centrum est idem quod centrum terrae Prop. 5. Solidarum magnitudinum quaecunque levior humido fuerit demissa in humidum manens usque eò demergetur ut tanta moles humidi quanta est partis demersae eandem quam tota magnitudo gravitatem habeat Prop. 6. Solidae magnitudines humido leviores in humidum impulsae sursum feruntur tanta vi quantò humidum molem habens magnitudini aequalem gravius est ipsâ magnitudine Prop. 7. Solidae magnitudines humido graviores demissae in humidum ferentur deorsum donec descendant Et erunt in humido tantò leviores quanta est gravitas humidi molem habentis solidae magnitudini aequalem Stevini Postul 3. Pondus à quo vas minus altè deprimitur levius quò altiùs gravius quò aeque altè aequipondium esse Prop. 5. Corpus solidum materiae levioris quà m aquâ—… cui innatat pondere aequale est tantae aquae moli quanta suae parti demergitur Prop. 8. Corpus solidum in aqua levius est quà m in aëre pondere aquae magnitudine sibi aequalis Prop. 10. Aquae fundo horizonti parallelo tantum insidet pondus quantum est aquae columnae cujus basis fundo altitudo perpendiculari ab aquae superficie summa ad imam demissae aequalis sit Now Reader consider well these Propositions my Authors Theorems and my Censure which is this His first two are no Theorems but only Suppositions And the third a sort of a definition or rather aliquid gratis dictum The fourth as he wordeth it is false for a broad fluid counterpoyseth more then a narrower seing a cylinder of Mercury one inch thick and twenty-nine inches high counterpoyseth a cylinder of Air of the same thickness and of the altitude of the Atmosphere and one two inches thick with the former height counterpoyseth four times as much Air. As he explicateth it it is true and the same with Archimedes's second Proposition for the Demonstration holds suppose ye divide the fluid by several pipes if they have entercourse Here he maketh a mystery of a very easie thing for one pillar of water being ten times thicker then another of the same height and consequently an hundred times heavier hath no more effect then the other for because of its base it hath an hundred times as much resistance And it is most clear that if the resistance be proportional to the pressure the effect must constantly be the same His fift is a part of Archimedes's first position His sixt also for Archimedes's expulsion hindered with equal resistance on all sides he calleth Pressure on every side I suppose he will hardly affirm that this lateral pressure was not known before him seeing Stevinus doth demonstrat how much it is upon any plain howsoever inclining in his Prop. 11. 12. 13. which our Author cannot do yet at least there is nothing in his Book either so subtil or useful His seventh is the same with the last part of Stevinus's third Postulatum The eight is manifestly false if fluids have a Bensil as he supposeth Prop. 17. 19. which I demonstrat from his own figure thus The first foot E having one degree of weight and the second foot I having equal quantity or dimension and being lower then E must have more weight according to his 17. let it therefore have 1½ degrees of weight then the weight of both these must be 2½ Now the third foot N being of equal quantity with I and lower must according to his 17. have more gravity then it hath to wit 1½ let it therefore have 2. degrees and then the weight of all three is 4½ degrees but 1. 2½ 4½ are not in Arithmetical progression and therefore the Theorem is false I must take notice that if our Author had understood so much as the terms of Art he would have said The pressures of fluids are in direct proportion with their profundities His inference there concerning a Geometrical progression is false for there are many Geometrical progressions more then 1 2 4 8 c. And it may be in many several progressions albeit it neither be in Arithmetical nor Geometrical progression And suppose he had not contradicted himself his Theorem is evident from the 10. of Stevinus For according to it the weights or pressures of fluids are equal to the weights of respective Cylinders upon the same or equal bases but the weights of such Cylinders are in proportion with their quantities which is the same with the proportion of their altitudes The ninth and tenth as he explicateth himself are only this That fluids press upon bodies within themselves and press up bodies lighter then themselves in specie which is the same with his 6. and 13. The first of which we have examined already and the other we leave to its own place But what ground he hath for his sensible and insensible gravity I shal discuss in the examination of his Ars magna nova which is all built upon this wild notion His eleventh is manifestly false as I shal afterward demonstrat from his own principles for the Cylinder acquireth only a greater base our Author must understand that an Horizontal surface is the base and sustains the pressure and consequently a greater resistance which maketh the same weight of less effect It is evident that a weight of lead cannot press two foot in square so much as one yea the pressures of the same weight are alwayes caeteris paribus in reciprocal proportion with the