Tide opposed The answer to the objections made against the motion of the Terrestrial Globe * Corpulenta The Water more apt to conserve an impetus conceived then the Air. Light bodies easier to be moved than heavy but less apt to conserve the motion It s more rational that the Air be commoved by the rugged surface of the Earth than by the Celestial motion The revolution of the Earth confirmed by a new argument taken from the Air. The vaporous parts of the earth partake of its motions Constant gales within the Tropicks blow towards the VVest The course to the VVest India's easie the return difficult Winds from Land make rough the Seas Another observation taken from the Air in confirmation of the motion of the Earth * Which Wind with our English Mariners is called the Trade-wind The voiages in the Mediterrane from East to West are made in shorter times than from West to East It is demonstrated inverting the argument that the perpetual motion of the Air from East to West cometh from the motion of Heaven It is demonstrated inverting the argument that the perpetual motion of the Air from East to VVest cometh from the motion of Heaven The motion of the VVater dependeth on the motion of Heaven The flux and reflux may depend on the diurnal motion of Heaven A reason of the continual motion of the Air and VVater may be given making the Earth moveable then by making it immoveable It s improbable that the element of Fire should be carried round by the Concave of the Moon †A Treatise of our Author formerly cited The Ebbing and Flowing cannot depend on the motion of Heaven The alterations in the effects argue alteration in the cause The causes as large assigned of the Periods Monethly and Annual of the ebbings and flowings The monethly and annual alterations of the tide can depend upon nothing save on the alteration of the additions substractions of the diurnal period from the annual Three wayes of altering the proportion of the additions of the diurnal Revolution to the annual motion That which to us is hard to be understood is with Nature easie to be effected If the Diurnal motion should not alter the annual Period would cease The true Hypothesis may dispatch its revolutions in a shorter time in lesser circles than in greater the which is proved by two examples The first example The second example Two particular notable accidents in the penduli and their vibrations Admirable Problems of moveables descending by the Quadrant of a Circle and of those descending by all the cords of the whole Circle The Earths annual motion by the Ecliptick unequal by means of the Moons motion Many things may remain as yet unobserved in Astronomy Saturn for its slowness and Mercury for its rareness of appearing were amongst those that were last observed Particular structures of the Orbs of the Planets not yet well resolved The Sun passeth one half of the Zodiack nine days sooner than the other The Moons motion principally sought in the account of Eclipses Ebbings and flowings are petty things in comparison of the vastness of Seas and of the velocity of the motion of the Terrestrial Globe The causes of the inequality of the additions and substractions of the diurnal conversion from the annual motion One single motion of the terrestrial Globe sufficeth not to produce the Ebbing Flowing The opinion of Seleucus the Mathematician censured Kepler is with respect blamed Sig. Caesare Marsilius observeth the Meridian to be moveable a Nunc autem servatâ semper moderatione praegravitatis nihil credere de re observá temerè debemus 〈◊〉 forie quod postea veritas pâ—â—efecerit quamvis Libris Sanctis sive Testamenâ— Vetris sive Novi nullo modó esse possit adversum tamen propter amorem nostri erroris oderimus Lib. 2. Genesi ad Literam in fine c Si fortasscerunt Mataeologi qui cum omnum Mathematicum ignari sint tamen de â—is judicium assumunt propter aliquem locum Scripturae malè ad suum propositum detortum ausi fuerint hoc meum institutum repreâ—endere ac insectari illos nihil moror adeò ut etiam illorum judicium tanquam temerarium contemnam Non enim obscurum est Lactantium celelebrem alioqui Scriptorem sed Mathematicum parvum admodum pueriliter de forma Terrae loqui cùm deridet eos qui Terram Globâ— formam habere prodiderunt Itaque non debet mirum videri studiosis si qui tales nos etiam ridebunt Mathemata Mathematicis scribuntur quibus hi nostri labores si me non fallit opinio videbuntur etiam Reipublicae Ecclesiasticae conducere aliquid cujus Principatum Tua Sanctitas nunc tenâ—â— c Not definimus Deum primò Nâ—tura cognoscendum Deinde Doctrina recognescendum Natura ex operibus Doctrina ex pâ—aedicationibus Tertul. adver Marcion lib. 1. cap. 18. c Quaeri etiam solet quae forma figura Caeli credenda sit secundum Scripturas nostras Multi enim multum disputant de iis ribus quas majori prudentia nostri Autores omiserunt ad beatam vitam non profuturas discentibus occupaentes quod prius est multum prolixaâ— rebus salubribus impendenda temporum spatiae Quid enim ad â—e pertinet utrum Caelum sicut Sphaera undique concludat Terram in media Mundi â—ole libratam an eam ex una parte desuper velut discus operiat Sed quiaâ— de Fide agitur Scripturarum propter illam causam quam non semel commemoravimus Ne scilicet quisquam eloquia divina non intelligens cum de his rebus tale aliquid vel invenerit in Libris Nostris vel ex illis audiverit quod perceptis assertionibus adversari videatur nullo modo eis cetera utilia monentibus vel narrantibus vel praeâ—â—â—ntiantibus credat Breviter discendum est de figura Caeli hoc scisse Autores nostros quod veritas habet Sed Spiritum Dei qui per ipsos loquebatur noluisse ista docere homines nulli ad salutem profutura D. August Lib. 2. De Gen. ad literam Cap. 9. Idem etiam legitur apud Petrum Lombardum Magistrum Sententiarum d De Moitâ— etiam Caeli nonnulli fraâ—tres quaestionem movent utrum stet an moveatur quiaâ— si â—â—â—vetur inquiunt quomodo Firmamentum est Si autem stat quomodo Sydera quae in ipso fixa creduntur ab Oriente in Occidentem circuÌ„eunt Septentrionalibus breviores gyros juxta cardinem peragentibus ut Caelum si est alius nobis occulius cardo ex alio vertice sicut Sphaera si autem nullus alius cardo est vel uti discus rotari videatur Quibus respondeo Multum subtilibus laboriosis rationibus ista perquiri ut vere percipiaetur utrum ita an non ita sit quibus ineundis atque tractandis nec mihi jam tempus est nec illis esse debet quos ad salutem suam è Sanctae
I would very gladly understand how and why these corruptive contraries are so favourable to Daws and so cruel to Doves so indulgent to Stags and so hasty to Horses that they do grant to them many more years of life that is of incorruptibility than weeks to these Peaches and Olives are planted in the same soil exposed to the same heat and cold to the same wind and rains and in a word to the same contrarieties and yet those decay in a short time and these live many hundred years Furthermore I never was thorowly satisfied about this substantial transmutation still keeping within pure natural bounds whereby a matter becometh so transform'd that it should be necessarily said to be destroy'd so that nothing remaineth of its first being and that another body quite differing there-from should be thence produced and if I fancy to my self a body under one aspect and by and by under another very different I cannot think it impossible but that it may happen by a simple transposition of parts without corrupting or ingendring any thing a-new for we see such kinds of Metamorphoses dayly so that to return to my purpose I answer you that inasmuch as you go about to perswade me that the Earth can not move circularly by way of corruptibility and generability you have undertook a much harder task than I that with arguments more difficult indeed but no less concluding will prove the contrary SAGR. Pardon me Salviatus if I interrupt your discourse which as it delights me much for that I also am gravel'd with the same doubts so I fear that you can never conclude the same without altogether digressing from your chief design therefore if it be permitted to proceed in our first argument I should think that it were convenient to remit this question of generation and corruption to another distinct and single conference as also if it shall please you and Simplicius we may do by other particular questions which may fall in the way of our discourse which I will keep in my mind to propose and exactly discuss them some other time Now as for the present since you say that if Aristotle deny circular motion to the Earth in common with other bodies Coelestial it thence will follow that the same which befalleth the Earth as to its being generable alterable c. will hold also of Heaven let us enquire no further if there be such things in nature as generation and corruption or not but let us return to enquire what the Globe of the Earth doth SIMPL. I cannot suffer my ears to hear it question'd whether generation and corruption be in rerum naturâ it being a thing which we have continually before our eyes and whereof Aristotle hath written two whole Books But if you go about to deny the Principles of Sciences and question things most manifest who knows not but that you may prove what you will and maintain any Paradox And if you do not dayly see herbs plants animals to generate and corrupt what is it that you do see Also do you not continually behold contrarieties contend together and the Earth change into Water the Water turn to Air the Air into Fire and again the Air to condense into Clouds Rains Hails and Storms SAGR. Yes we see these things indeed and therefore will grant you the discourse of Aristotle as to this part of generation and corruption made by contraries but if I shall conclude by virtue of the same propositions which are granted to Aristotle that the Coelestial bodies themselves are also generable and corruptible aswell as the Elementary what will you say then SIMPL. I will say you have done that which is impossible to be done SAGR. Go to tell me Simplicius are not these affections contrary to one another SIMPL. Which SAGR. Why these Alterable unalterable passible impassible generable ingenerable corruptible incorruptible SIMPL. They are most contrary SAGR. Well then if this be true and it be also granted that Coelestial Bodies are ingenerable and incorruptible I prove that of necessity Coelestial Bodies must be generable and corruptible SIMPL. This must needs be a Sophism SAGR. Hear my Argument and then censure and resolve it Coelestial Bodies for that they are ingenerable and incorruptible have in Nature their contraries which are those Bodies that be generable and corruptible but where there is contrariety there is also generation and corruption therefore Coelestial Bodies are generable and corruptible SIMPL. Did I not say it could be no other than a Sophism This is one of those forked Arguments called Soritae like that of the Cretan who said that all Cretans were lyars but he as being a Cretan had told a lye in saying that the Cretans were lyars it followed therefore that the Cretans were no lyars and consequently that he as being a Cretan had spoke truth And yet in saying the Cretans were lyars he had said true and comprehending himself as a Cretan he must consequently be a lyar And thus in these kinds of Sophisms a man may dwell to eternity and never come to any conclusion SAGR. You have hitherto censured it it remaineth now that you answer it shewing the fallacie SIMPL. As to the resolving of it and finding out its fallacie do you not in the first place see a manifest contradiction in it Coelestial Bodies are ingenerable and incorruptible Ergo Coelestial Bodies are generable and corruptible And again the contrariety is not betwixt the Coelestial Bodies but betwixt the Elements which have the contrariety of the Motions sursùm and deorsùm and of levity and gravity But the Heavens which move circularly to which motion no other motion is contrary want contrariety and therefore they are incorruptible SAGR. Fair and softly Simplicius this contrariety whereby you say some simple Bodies become corruptible resides it in the same Body which is corrupted or else hath it relation to some other I say if for example humidity by which a piece of Earth is corrupted resides it in the same Earth or in some other bodie which must either be the Air or Water I believe you will grant that like as the Motions upwards and downwards and gravity and levity which you make the first contraries cannot be in the same Subject so neither can moist and dry hot and cold you must therefore consequently acknowledg that when a bodie corrupteth it is occasioned by some quality residing in another contrary to its own therefore to make the Coelestial Body become corruptible it sufficeth that there are in Nature bodies that have a contrariety to that Coelestial body and such are the Elements if it be true that corruptibility be contrary to incorruptibility SIMPL. This sufficeth not Sir The Elements alter and corrupt because they are intermixed and are joyn'd to one another and so may exercise their contrariety but Coelestial bodies are separated from the Elements by which they are not so much as toucht
downwards is no less natural and intrinsecal than that principle of light bodies vvhich moveth them upwards so that I propose to your consideration a ball of lead vvhich descending through the Air from a great altitude and so moving by an intern principle and comming to a depth of vvater continueth its descent and without any other externe mover submergeth a great vvay and yet the motion of descent in the vvater is preternatural unto it but yet nevertheless dependeth on a principle that is internal and not external to the ball You see it demonstrated then that a moveable may be moved by one and the same internal principle with contrary motions SIMP I believe there are solutions to all these objections though for the present I do not remember them but however it be the Author continueth to demand on what principle this circular motion of grave and light bodies dependeth that is whether on a principle internal or external and proceeding forvvards sheweth that it can be neither on the one nor on the other saying Si ab externo Deusne illum excitat per continuum miraculum an verò Angelus an aër Et hunc quidem multi assignant Sed contra In English thus If from an externe principle Whether God doth not excite it by a continued Miracle or an Angel or the Air And indeed many do assign this But on the contrary SALV Trouble not your self to read his argument for I am none of those who ascribe that principle to the ambient air As to the Miracle or an Angel I should rather incline to this side for that which taketh beginning from a Divine Miracle or from an Angelical operation as for instance the transportation of a Cannon ball or bullet into the concave of the Moon doth in all probability depend on the vertue of the same principle for performing the rest But as to the Air it serveth my turn that it doth not hinder the circular motion of the moveables which we did suppose to move thorow it And to prove that it sufficeth nor is more required that it moveth with the same motion and finisheth its circulations with the same velocity that the Terrestrial Globe doth SIMP And he likewise makes his opposition to this also demanding who carrieth the air about Nature or Violence And proveth that it cannot be Nature alledging that that is contrary to truth experience and to Copernicus himself SALV It is not contrary to Copernicus in the least who writeth no such thing and this Author ascribes these things to him with two excessive courtesie It 's true he saith and for my part I think he saith well that the part of the air neer to the Earth being rather a terrestrial evaporation may have the same nature and naturally follow its motion or as being contiguous to it may follow it in the same manner as the Peripateticks say that the superiour part of it and the Element of fire follow the motion of the Lunar Concave so that it lyeth upon them to declare whether that motion be natural or violent SIMP The Author will reply that if Copernicus maketh only the inferiour part of the Air to move and supposeth the upper part thereof to want the said motion he cannot give a reason how that quiet air can be able to carry those grave bodies along with it and make them keep pace with the motion of the Earth SALV Copernicus will say that this natural propension of the elementary bodies to follow the motion of the Earth hath a limited Sphere out of which such a natural inclination would cease besides that as I have said the Air is not that which carrieth the moveables along with it which being separated from the Earth do follow its motion so that all the objections come to nothing which this Author produceth to prove that the Air cannot cause such effects SIMP To shew therefore that that cannot be it will be necessary to say that such like effects depend on an interne principle against which position oboriuntur difficillimae immò inextricabiles quaestiones secundae of which sort are these that follow Principium illud internum vel est accidens vel substantia Si primum quale nam illud nam qualitas locomotiva circum hactenus nulla videtur agniâ—a In English thus Contrary to which position there do arise most difficult yea inextricable second questions such as these That intern principle is either an accident or a substance If the first what manner of accident is it For a locomotive quality about the centre seemeth to be hitherto acknowledged by none SALV How is there no such thing acknowledged Is it not known to us that all these elementary matters move round together with the Earth You see how this Author supposeth for true that which is in question SIMP He saith that we do not see the same and me thinks he hath therein reason on his side SALV We see it not because we turn round together with them SIMP Hear his other Argument Quae etiam si esset quomodò tamen inveniretur in rebus tam contrariis in igne ut in aquâ in aëre ut in terra in viventibus ut in animà carentibus in English thus Which although it were yet how could it be found in things so contrary in the fire as in the water in the air as in the earth in living creatures as in things wanting life SALV Supposing for this time that water and fire are contraries as also the air and earth of which yet much may be said the most that could follow from thence would be that those motions cannot be common to them that are contrary to one another so that v. g. the motion upwards which naturally agreeth to fire cannot agree to water but that like as it is by nature contrary to fire so to it that motion suiteth which is contrary to the motion of fire which shall be the motion deorsum but the circular motion which is not contrary either to the motion sursum or to the motion deorsum but may mix with both as Aristotle himself affirmeth why may it not equally suit with grave bodies and with light The motions in the next place which cannot be common to things alive and dead are those which depend on the soul but those which belong to the body in as much as it is elementary and consequently participateth of the qualities of the elements why may not they be common as well to the dead corps as to the living body And therefore if the circular motion be proper to the elements it ought to be common to the mixt bodies also SAGR. It must needs be that this Author holdeth that a dead cat falling from a window it is not possible that a live cat also could fall it not being a thing convenient that a carcase should partake of the qualities which suit with things alive SALV Therefore the discourse of this Author concludeth nothing against one
temperate heat able to make the Water swell bid them put fire under a Kettle full of Water and hold their right hand therein till that the Water by reason of the heat do rise but one sole inch and then let them take it out and write off the tumefaction of the Sea Or at least desire them to shew you how the Moon doth to rarefie a certain part of the Waters and not the remainder as for instance these here of Venice and not those of Ancona Naples Genova the truth is Poetick Wits are of two kinds some are ready and apt to invent Fables and others disposed and inclined to believe them SIMP I believe that no man believeth Fables so long as he knows them to be so and of the opinions concerning the causes of ebbing and flowing which are many because I know that of one single effect there is but one single cause that is true and primary I understand very well and am certain that but one alone at the most can be true and for all the rest I am sure that they are fabulous and false and its possible that the true one may not be among those that have been hitherto produced nay I verily believe that it is not for it would be very strange that the truth should have so little light as that it should not be visible amongst the umbrages of so many falshoods But this I shall say with the liberty that is permitted amongst us that the introduction of the Earths motion and the making it the cause of the ebbing and flowing of Tides seemeth to me as yet a conjecture no lesse fabulous than the rest of those that I have heard and if there should not be proposed to me reasons more conformable to natural matters I would without any more ado proceed to believe this to be a supernatural effect and therefore miraculous and unsearchable to the understandings of men as infinite others there are that immediately depend on the Omnipotent hand of God SAGR. You argue very prudently and according to the Doctrine of Aristotle who you know in the beginning of his mechanical questions referreth those things to a Miracle the causes whereof are occult But that the cause of the ebbing and flowing is one of those that are not to be found out I believe you have no greater proof than onely that you see that amongst all those that have hitherto been produced for true causes thereof there is not one wherewith working by what artifice you will we are able to represent such an effect in regard that neither with the light of the Moon nor of the Sun nor with temperate heats nor with different profundities shall one ever artificially make the Water conteined in an immoveable Vessel to run one way or another and to ebbe and flow in one place and not in another But if without any other artifice but with the onely moving of the Vessel I am able punctually to represent all those mutations that are observed in the Sea Water why will you refuse this reason and run to a Miracle SIMP I will run to a Miracle still if you do not with some other natural causes besides that of the motion of the Vessels of the Sea-water disswade me from it for I know that those Vessels move not in regard that all the entire Terrestrial Globe is naturally immoveable SALV But do not you think that the Terrestrial Globe might supernaturally that is by the absolute power of God be made moveable SIMP Who doubts it SALV Then Simplicius seeing that to make the flux and reflux of the Sea it is necessary to introduce a Miracle let us suppose the Earth to move miraculously upon the motion of which the Sea moveth naturally and this effect shall be also the more simple and I may say natural amongst the miraculous operations in that the making a Globe to move round of which kind we see many others to move is lesse difficult than to make an immense masse of water go forwards and backwards in one place more swiftly and in another lesse and to rise and fall in some places more in some lesse and in some not at all and to work all these different effects in one and the same Vessel that containeth it besides that these are several Miracles and that is but one onely And here it may be added that the Miracle of making the water to move is accompanied with another namely the holding of the Earth stedfast against impetuosities of the water able to make it swage sometimes one way and sometimes another if it were not miraculously kept to rights SAGR. God Simplicius let us for the present suspend our judgement about sentencing the new opinion to be vain that Salviatus is about to explicate unto us nor let us so hastily flye out into passion like the scolding overgrown Haggs and as for the Miracle we may as well recurre to it when we have done hearing the Discourses contained within the bounds of natural causes though to speak freely all the Works of nature or rather of God are in my judgement miraculous SALV And I am of the same opinion nor doth my saying that the motion of the Earth is the Natural cause of the ebbing and flowing hinder but that the said motion of the Earth may be miraculous Now reassuming our Argument I apply and once again affirm that it hath been hitherto unknown how it might be that the Waters contained in our Mediterranean Straights should make those motions as we see it doth if so be the said Straight or containing Vessel were immoveable And that which makes the difficulty and rendreth this matter inextricable are the things which I am about to speak of and which are daily observed Therefore lend me your attention We are here in Venice where at this time the Waters are low the Sea calm the Air tranquil suppose it to be young flood and that in the term of five or six hours the water do rise ten hand breadths and more that rise is not made by the first water which was said to be rarefied but it is done by the accession of new Water Water of the same sort with the former of the same brackishness of the same density of the same weight Ships Simplicius float therein as in the former without drawing an hairs breadth more water a Barrel of this second doth not weigh one single grain more or less than such another quantity of the other and retaineth the same coldness without the least alteration And it is in a word Water newly and visibly entred by the Channels and Mouth of the Lio. Consider now how and from whence it came thither Are there happly hereabouts any Gulphs or Whirle-pools in the bottom of the Sea by which the Earth drinketh in and spueth out the Water breathing as it were a great and monstruous Whale But if this be so how comes it that the Water doth not flow in
by SIGNORE BARTOLOTTI in that affair of the DIVERSION of FIUME MORTO IX HIS CONSIDERATION upon the DRAINING of the PONTINE FENNS in CALABRIA X. HIS CONSIDERATION upon the DRAINING of the TERRITORIES of BOLOGNA FERRARA and ROMAGNA XI HIS LETTER to D. FERRANTE CESARINI applying his DOCTRINE to the MENSURATION of the LENGTH and DISTRIBUTION of the QUANTITY of the WATERS of RIVERS SPRINGS AQUEDUCTS c. XII D. CORSINUS SUPERINTENDENT of the GENERAL DRAINS and PRESIDENT of ROMAGNA his RELATION of the state of the VVATERS in the TERRITORIES of BOLOGNA and FERRARA A Table of the most observable Persons and Matters mentioned in the Second Part. The CONTENTS of the SECOND TOME PART THE FIRST Treatise I. GALILEUS GALILEUS his MATHEMATICAL DISCOURSES and DEMONSTRATIOMS touching two NEVV SCIENCES pertaining to the MECHANICKS and LOCAL MOTION with an APPENDIX of the CENTRE of GRAVITY of some SOLIDS in Four DIALOGUES II. HIS MECHANICKS a New PEICE III. RHENATUS DES CARTES his MECHANICKS translated from his FRENCH MANUSCRIPT a New PEICE IV. ARCHIMEDES his Tract DE INSIDENTIBUS HUMIDO with the NOTES and DEMONSTRASIONS of NICOLAUS TARTALEUS in Two BOOKS V. GALILEUS his DISCOURSE of the things that move in or upon the WATER VI. NICOLAUS TARTALEUS his INVENTIONS for DIVING UNDER WATER RAISING OF SHIPS SUNK c. in Two BOOKS PART THE SECOND I. EVANGELISTA TORRICELLIUS his DOCTRINE OF PROJECTS and TABLES of the RANGES of GREAT GUNNS of all sorts wherein he detects sundry ERRORS in GUNNERY An EPITOME II. T. S. his EXPERIMENTS of the COMPARATIVE GRAVITY OF BODIES in the AIRE and WATER III. GALILEUS GALILEUS his LIFE in Five BOOKS BOOK I. Containing Five Chapters Chap. 1. His Country 2. His Parents and Extraction 3. His time of Birth 4. His first Education 5. His Masters II. Containing Three Chapters Chap. 1. His judgment in several Learnings 2. His Opinions and Doctrine 3. His Auditors and Scholars III. Containing Four Chapters Chap. 1. His behaviour in Civil Affairs 2. His manner of Living 3. His morall Virtues 4. His misfortunes and troubles IV. Containing Four Chapters Chap. 1. His person described 2. His Will and Death 3. His Inventions 4. His Writings 5. His Dialogues of the Systeme in particular containing Nine Sections Section 1. Of Astronomy in General its Definition Praise Original 2. Of Astronomers a Chronological Catalogue of the most famous of them 3. Of the Doctrine of the Earths Mobility c. its Antiquity and Progresse from Pythagoras to the time of Copernicus 4. Of the Followers of Copernicus unto the time of Galileus 5. Of the severall Systemes amongst Astronomers 6. Of the Allegations against the Copern Systeme in 77 Arguments taken out of Ricciolo with Answers to them 7. Of the Allegations for the Copern Systeme in 50 Arguments 8. Of the Scriptures Authorities produced against and for the Earths mobility 9. The Conclusion of the whole Chapter V. Containing Four Chapters Chap. 1. His Patrons Friends and Emulators 2. Authors judgments of him 3. Authors that have writ for or against him 4. A Conclusion in certain Reflections upon his whole Life A Table of the whole Second TOME GALILAEUS Galilaeus Lyncaeus HIS SYSTEME OF THE WORLD The First Dialogue INTERLOCVTORS SALVIATUS SAGREDUS and SIMPLICIUS SALVIATUS IT was our yesterdayes resolution and agreement that we should to day discourse the most distinctly and particularly we could possible of the natural reasons and their efficacy that have been hitherto alledged on the one or other part by the maintainers of the Positions Aristotelian and Ptolomaique and by the followers of the Copernican Systeme And because Copernicus placing the Earth among the moveable Bodies of Heaven comes to constitute a Globe for the fame like to a Planet it would be good that we began our disputation with the examination of what and how great the energy of the Peripateticks arguments is when they demonstrate that this Hypothesis is impossible Since that it is necessary to introduce in Nature substances different betwixt themselves that is the Coelestial and Elementary that impassible and immortal this alterable and corruptible Which argument Aristotle handleth in his book De Coelo insinuating it first by some discourses dependent on certain general assumptions and afterwards confirming it with experiments and perticular demonstrations following the same method I will propound and freely speak my judgement submitting my self to your censure and particularly to Simplicius a Stout Champion and contender for the Aristotelian Doctrine And the first Step of the Peripatetick arguments is that where Aristotle proveth the integrity and perfection of the World telling us that it is not a simple line nor a bare superficies but a body adorned with Longitude Latitude and Profundity and because there are no more dimensions but these three The World having them hath all and having all is to be concluded perfect And again that by simple length that magnitude is constituted which is called a Line to which adding breadth there is framed the Superficies and yet further adding the altitude or profoundity there results the Body and after these three dimensions there is no passing farther so that in these three the integrity and to so speak totality is terminated which I might but with justice have required Aristotle to have proved to me by necessary consequences the rather in regard he was able to do it very plainly and speedily SIMPL. What say you to the excellent demonstrations in the 2. 3. and 4. Texts after the definition of Continual have you it not first there proved that there is no more but three dimensions for that those three are all things and that they are every where And is not this confirmed by the Doctrine and Authority of the Pythagorians who say that all things are determined by three beginning middle and end which is the number of All And where leave you that reason namely that as it were by the law of Nature this number is used in the sacrifices of the Gods And why being so dictated by nature do we atribute to those things that are three and not to lesse the title of all why of two is it said both and not all unless they be three And all this Doctrine you have in the second Text. Afterwards in the third Ad pleniorem scientiam we read that All the Whole and Perfect are formally one and the same and that therefore onely the Body amongst magnitudes is perfect because it is determined by three which is All and being divisible three manner of waies it is every way divisible but of the others some are dividible in one manner and some in two because according to the number affixed they have their division and continuity and thus one magnitude is continuate one way another two a third namely the Body every way Moreover in the fourth Text doth he not after some other Doctrines prove it by another demonstration Scilicet That no transition is made but
to any velocity acquired by the moveable in that time and therefore before we go any farther I will seek to remove this difficulty which shall be an easie task for I reply that the moveable passeth by the aforesaid degrees but the passage is made without staying in any of them so that the passage requiring but one sole instant of time and every small time containing infinite instants we shall not want enough of them to assign its own to each of the infinite degrees of tardity although the time were never so short SAGR. Hither to I apprehend you nevertheless it is very much that that Ball shot from a Cannon for such I conceive the cadent moveable which yet we see to fall with such a precipice that in less than ten pulses it will pass two hundred yards of altitude should in its motion be 〈…〉 joyned with so small a degree of velocity that should 〈…〉 to have moved at that rate without farther 〈…〉 it would not have past the same in a day SALV You may say nor 〈…〉 nor in ten no nor in a thousand as I will endeavour 〈…〉 you and also happily without your contradiction to some 〈◊〉 simple questions that I will propound to you Therefore tell me if you make any question of granting that that that ball in descending goeth increasing its impetus and velocity SAGR. I am most certain it doth SALV And if I should say that the impetus acquired in any place of its motion is so much that it would suffice to re-carry it to that place from which it came would you grant it SAGR. I should consent to it without contradiction provided alwaies that it might imploy without impediment its whole impetus in that sole work of re-conducting it self or another equal to it to that self-same height as it would do in case the Earth were bored thorow the centre and the Bullet fell a thousand yards from the said centre for I verily believe it would pass beyond the centre ascending as much as it had descended and this I see plainly in the experiment of a plummet hanging at a line which removed from the perpendicular which is its state of rest and afterwards let go falleth towards the said perpendicular and goes as far beyond it or onely so much less as the opposition of the air and line or other accidents have hindred it The like I see in the water which descending thorow a pipe re-mounts as much as it had descended SALV You argue very well And for that I know you will not scruple to grant that the acquist of the impetus is by means of the receding from the term whence the moveable departed and its approach to the centre whither it motion tendeth will you stick to yeeld that two equal moveables though descending by divers lines without any impediment acquire equal impetus provided that the approaches to the centre be equal SAGR. I do not very well understand the question SALV I will express it better by drawing a Figure therefore I will suppose the line AB in Fig. 3. parallel to the Horizon and upon the point B I will erect a perpendicular BC and after that I adde this slaunt line CA. Understanding now the line CA to be an inclining plain exquisitely polished and hard upon which descendeth a ball perfectly round and of very hard matter and such another I suppose freely to descend by the perpendicular CB will you now confess that the impetus of that which descends by the plain CA being arrived to the point A may be equal to the impetus acquired by the other in the point B after the descent by the perpendicular CB SAGR. I resolutely believe so for in effect they have both the same proximity to the centre and by that which I have already granted their impetuosities would be equally sufficient to re-carry them to the same height SALV Tell me now what you believe the same ball would do put upon the Horizontal plane AB SAGR. It would lie still the said plane having no declination SALV But on the inclining plane CA it would descend but with a gentler motion than by the perpendicular CB SAGR. I may confidently answer in the affirmative it seeming to me necessary that the motion by the perpendicular CB should be more swift than by the inclining plane CA yet nevertheless if this be how can the Cadent by the inclination arrived to the point A have as much impetus that is the same degree of velocity that the Cadent by the perpendicular shall have in the point B these two Propositions seem contradictory SALV Then you would think it much more false should I say that the velocity of the Cadents by the perpendicular and inclination are absolutely equal and yet this is a Proposition most true as is also this that the Cadent moveth more swiftly by the perpendicular than by the inclination SAGR. These Propositions to my ears sound very harsh and I believe to yours Simplicius SIMPL. I have the same sense of them SALV I conceit you jest with me pretending not to comprehend what you know better than my self therefore tell me Simplicius when you imagine a moveable more swift than another what conceit do you fancy in your mind SIMPL. I fancie one to pass in the same time a greater space than the other or to move equal spaces but in lesser time SALV Very well and for moveables equally swift what 's your conceit of them SIMPL. I fancie that they pass equal spaces in equal times SALV And have you no other conceit thereof than this SIMPL. This I think to be the proper definition of equal motions SAGR. We will add moreover this other and call that equal velocity when the spaces passed have the same proportion as the times wherein they are past and it is a more universal definition SALV It is so for it comprehendeth the equal spaces past in equal times and also the unequal past in times unequal but proportionate to those spaces Take now the same Figure and applying the conceipt that you had of the more hastie motion tell me why you think the velocity of the Cadent by CB is greater than the velocity of the Descendent by CA SIMPL. I think so because in the same time that the Cadent shall pass all CB the Descendent shall pass in CA a part less than CB. SALV True and thus it is proved that the moveable moves more swiftly by the perpendicular than by the inclination Now consider if in this same Figure one may any way evince the other conceipt and finde that the moveables were equally swift by both the lines CA and CB. SIMPL. I see no such thing nay rather it seems to contradict what was said before SALV And what say you Sagredus I would not teach you what you knew before and that of which but just now you produced me the definition SAGR. The definition I gave you
leave and part from the same term and because in circular motion the moveable continually leaves the natural term and continually moveth towards the same therefor in it the repugnance and inclination are always of equal force from which equality results a velocity neither retarded nor accelerated i. e. an uniformity in motion From this conformity and from the being terminate may follow the perpetual continuation by successively reiterating the circulations which in an undeterminated line and in a motion continually retarded or accelerated cannot naturally be I say naturally because the right motion which is retarded is the violent which cannot be perpetual and the accelerate arriveth necessarily at the term if one there be and if there be none it cannot be moved to it because nature moves not whether it is impossible to attain I conclude therefore that the circular motion can onely naturally consist with natural bodies parts of the universe and constituted in an excellent disposure and that the right at the most that can be said for it is assigned by nature to its bodies and their parts at such time as they shall be out of their proper places constituted in a depraved disposition and for that cause needing to be reduâ—â—d by the shortest way to their natural state Hence me thinks it may rationally be concluded that for maintenance of perfect order amongst the parts of the World it is necessary to say that moveables are moveable onely circularly and if there be any that move not circularly these of necessity are immoveable there being nothing but rest and circular motion apt to the conservation of order And I do not a little wonder with my self that Aristotle who held that the Terrestrial globe was placed in the centre of the World and there remained immoveable should not say that of natural bodies some are moveable by nature and others immoveable especially having before defined Nature to be the principle of Motion and Rest. SIMPL. Aristotle though of a very perspicacious wit would not strain it further than needed holding in all his argumentations that sensible experiments were to be preferred before any reasons founded upon strength of wit and said those which should deny the testimony of sense deserved to be punished with the loss of that sense now who is so blind that sees not the parts of the Earth and Water to move as being grave naturally downwards namely towards the centre of the Universe assigned by nature her self for the end and term of right motion deorsùm and doth not likewise see the Fire and Air to move right upwards towards the Concave of the Lunar Orb as to the natural end of motion sursùm And this being so manifestly seen and we being certain that eadem est ratio totius partium why may we not assert it for a true and manifest proposition that the natural motion of the Earth is the right motion ad medium and that of the Fire the right à medio SALV The most that you can pretend from this your Discourse were it granted to be true is that like as the parts of the Earth removed from the whole namely from the place where they naturally rest that is in short reduced to a depraved and disordered disposure return to their place spontaneously and therefore naturally in a right motion it being granted that eadem sit ratio totius partium so it may be inferred that the Terrestrial Globe removed violently from the place assigned it by nature it would return by a right line This as I have said is the most that can be granted you and that onely for want of examination but he that shall with exactness revise these things will first deny that the parts of the Earth in returning to its whole move in a right line and not by a circular or mixt and really you would have enough to do to demonstrate the contrary as you shall plainly see in the answers to the particular reasons and experiments alledged by Ptolomey and Aristotle Secondly If another should say that the parts of the Earth go not in their motion towards the Centre of the World but to unite with its Whole and that for that reason they naturally incline towards the centre of the Terrestrial Globe by which inclination they conspire to form and preserve it what other All or what other Centre would you find for the World to which the whole Terrene Globe being thence removed would seek to return that so the reason of the Whole might be like to that of its parts It may be added That neither Aristotle nor you can ever prove that the Earth de facto is in the centre of the Universe but if any Centre may be assigned to the Universe we shall rather find the Sun placed in it as by the sequel you shall understand Now like as from the consentaneous conspiration of all the parts of the Earth to form its whole doth follow that they with equal inclination concurr thither from all parts and to unite themselves as much as is possible together they there spherically adapt themselves why may we not believe that the Sun Moon and other mundane Bodies be also of a round figure not by other than a concordant instinct and natural concourse of all the parts composing them Of which if any at any time by any violence were separated from the whole is it not reasonable to think that they would spontaneously and by natural instinct return and in this manner to infer that the right motion agreeth with all mundane bodies alike SIMPL. Certainly if you in this manner deny not onely the Principles of Sciences but manifest Experience and the Senses themselves you can never be convinced or removed from any opinion which you once conceit therefore I will choose rather to be silent for contra negantes principia non est disputandum than contend with you And insisting on the things alledged by you even now since you question so much as whether grave moveables have a right motion or no how can you ever rationally deny that the parts of the Earth or if you will that ponderous matters descend towards the Centre with a right motion whenas if from a very high Tower whose walls are very upright and perpendicular you let them fall they shall descend gliding and sliding by the Tower to the Earth exactly in that very place where a plummet would fall being hanged by a line fastned above just there whence the said weights were let fall is not this a more than evident argument of the motions being right and towards the Centre In the second place you call in doubt whether the parts of the Earth are moved as Aristotle affirms towards the Centre of the World as if he had not rationally demonstrated it by contrary motions whilst he thus argueth The motion of heavie bodies is contrary to that of the light but the motion
move And as to the motion by a right line they must grant us that Nature maketh use of it to reduce the small parts of the Earth Water Air Fire and every other integral Mundane body to their Whole when any of them by chance are separated and so transported out of their proper place if also haply some circular motion might not be found to be more convenient to make this restitution In my judgment this primary position answers much better even according to Aristotles own method to all the other consequences than to attribute the straight motion to be an intrinsick and natural principle of the Elements Which is manifest for that if I aske the Peripatetick if being of opinion that Coelestial bodies are incorruptibe and eternal he believeth that the Terrestial Globe is not so but corruptible and mortal so that there shall come a time when the Sun and Moon and other Stars continuing their beings and operations the Earth shall not be found in the World but shall with the rest of the Elements be destroyed and annihilated I am certain that he would answer me no therefore generation and corruption is in the parts and not in the whole and in the parts very small and superficial which are as it were incensible in comparison of the whole masse And because Aristotle deduceth generation and corruption from the contrariety of streight motions let us remit such motions to the parts which onely change and decay and to the whole Globe and Sphere of the Elements let us ascribe either the circular motion or a perpetual consistance in its proper place the only affections apt for perpetuation and maintaining of perfect order This which is spoken of the Earth may be said with the same reason of Fire and of the greatest part of the Air to which Elements the Peripateticks are forced to ascribe for intrinsical and natural a motion wherewith they were never yet moved nor never shall be and to call that motion preternatural to them wherewith if they move at all they do and ever shall move This I say because they assign to the Air and Fire the motion upwards wherewith those Elements were never moved but only some parts of them and those were so moved onely in order to the recovery of their perfect constitution when they were out of their natural places and on the contrary they call the circular motion preternatural to them though they are thereby incessantly moved forgeting as it seemeth what Aristotle oft inculcateth that nothing violent can be permanent SIMPL. To all these we have very pertinent answers which I for this time omit that we may come to the more particular reasons and sensible experiments which ought in conclusion to be opposed as Aristotle saith well to whatever humane reason can present us with SAGR. What hath been spoken hitherto serves to clear up unto us which of the two general discourses carrieth with it most of probability I mean that of Aristotle which would perswade us that the sublunary bodies are by nature generable and corruptible c. and therefore most different from the essence of Coelestial bodies which are impassible ingenerable incorruptible c. drawn from the diversity of simple motions or else this of Salviatus who supposing the integral parts of the World to be disposed in a perfect constitution excludes by necessary consequence the right or straight motion of simple natural bodies as being of no use in nature and esteems the Earth it self also to be one of the Coelestial bodies adorn'd with all the prerogatives that agree with them which last discourse is hitherto much more likely in my judgment than that other Therefore resolve Simplicius to produce all the particular reasons experiments and observations as well Natural as Astronomical that may serve to perswade us that the Earth differeth from the Coelestial bodies is immoveable and situated in the Centre of the World and what ever else excludes its moving like to the Planets as Jupiter or the Moon c. And Salviatus will be pleased to be so civil as to answer to them one by one SIMPL. See here for a begining two most convincing Arguments to demonstrate the Earth to be most different from the Coelestial bodies First the bodies that are generable corruptible alterable c. are quite different from those that are ingenerable incorruptible unalterable c. But the Earth is generable corruptible alterable c. and the Coelestial bodies ingenerable incorruptible unalterable c. Therefore the Earth is quite different from the Coelestial bodies SAGR. By your first Argument you spread the Table with the same Viands which but just now with much adoe were voided SIMPL. Hold a little Sir and take the rest along with you and then tell me if this be not different from what you had before In the former the Minor was proved à priori now you see it proved à posteriori Judg then if it be the same I prove the Minor therefore the Major being most manifest by sensible experience which 〈…〉 that in the Earth there are made continual generations corruptions alterations c. which neither our senses nor the traditions or memories of our Ancestors ever saw an instance of in Heaven therefore Heaven is unalterable c. and the Earth alterable c. and therefore different from Heaven I take my second Argument from a principal and essential accident and it is this That body which is by its nature obscure and deprived of light is divers from the luminous and shining bodies but the Earth is obscure and void of light and the Coelestial bodies splendid and full of light Ergo c. Answer to these Arguments first that we may not heap up too many and then I will alledge others SALV As to the first the stresse whereof you lay upon experience I desire that you would a little more distinctly produce me the alteration which you see made in the Earth and not in Heaven upon which you call the Earth alterable and the Heavens not so SIMPL. I see in the Earth plants and animals continually generating and decaying winds rains tempests storms arising and in a word the aspect of the Earth to be perpetually metamorphosing none of which mutations are to be discern'd in the Coelestial bodies the constitution and figuration of which is most punctually conformable to that they ever were time out of mind without the generation of any thing that is new or corruption of any thing that was old SALV But if you content your self with these visible or to say better seen experiments you must consequently account China and America Coelestial bodies for doubtlesse you never be held in them these alterations which you see here in Italy and that therefore according to your apprehension they are inalterable SIMPL. Though I never did see these alterations sensibly in those places the relations of them are not to be questioned besides that cum eadem
And because in the last place the bird swending its flight towards the West was no other than a withdrawing from the diurnal motion which hath suppose ten degrees of velocity one degree onely there did thereupon remain to the bird whil'st it was in its flight nine degrees of velocity and so soon as it did alight upon the the Earth the ten common degrees returned to it to which by flying towards the East it might adde one and with those eleven overtake the Tower And in short if we well consider and more narrowly examine the effects of the flight of birds they differ from the projects shot or thrown to any part of the World in nothing save onely that the projects are moved by an external projicient and the birds by an internal principle And here for a final proof of the nullity of all the experiments before illedged I conceive it now a time and place convenient to demonstrate a way how to make an exact trial of them all Shut your self up with some friend in the grand Cabbin between the decks of some large Ship and there procure gnats flies and such other small winged creatures get also a great tub or other vessel full of water and within it put certain fishes let also a certain bottle be hung up which drop by drop letteth forth its water into another bottle placed underneath having a narrow neck and the Ship lying still observe diligently how those small winged animals fly with like velocity towards all parts of the Cabin how the fishes swim indifferently towards all sides and how the distilling drops all fall into the bottle placed underneath And casting any thing towards your friend you need not throw it with more force one way then another provided the distances be equal and leaping as the saying is with your feet closed you will reach as far one way as another Having observed all these particulars though no man doubteth that so long as the vessel stands still they ought to succeed in this manner make the Ship to move with what velocity you please for so long as the motion is uniforme and not fluctuating this way and that way you shall not discern any the least alteration in all the forenamed effects nor can you gather by any of them whether the Ship doth move or stand still In leaping you shall reach as far upon the floor as before nor for that the Ship moveth shall you make a greater leap towards the poop than towards the prow howbeit in the time that you staid in the Air the floor under your feet shall have run the contrary way to that of your jump and throwing any thing to your companion you shall not need to cast it with more strength that it may reach him if he shall be towards the prow and you towards the poop then if you stood in a contrary situation the drops shall all distill as before into the inferiour bottle and not so much as one shall fall towards the poop albeit whil'st the drop is in the Air the Ship shall have run many feet the Fishes in their water shall not swim with more trouble towards the fore-part than towards the hinder part of the tub but shall with equal velocity make to the bait placed on any side of the tub and lastly the flies and gnats shall continue their flight indifferently towards all parts nor shall they ever happen to be driven together towards the side of the Cabbin next the prow as if they were wearied with following the swift course of the Ship from which through their suspension in the Air they had been long separated and if burning a few graines of incense you make a little smoke you shall see it ascend on high and there in manner of a cloud suspend it self and move indifferently not inclining more to one side than another and of this correspondence of effects the cause is for that the Ships motion is common to all the things contained in it and to the Air also I mean if those things be shut up in the Cabbin but in case those things were above deck in the open Air and not obliged to follow the course of the Ship differences more or lesse notable would be observed in some of the fore-named effects and there is no doubt but that the smoke would stay behind as much as the Air it self the flies also and the gnats being hindered by the Air would not be able to follow the motion of the Ship if they were separated at any distance from it But keeping neer thereto because the Ship it self as being an unfractuous Fabrick carrieth along with it part of its neerest Air they would follow the said Ship without any pains or difficulty And for the like reason we see sometimes in riding post that the troublesome flies and hornets do follow the horses flying sometimes to one sometimes to another part of the body but in the falling drops the difference would be very small and in the salts and projections of grave bodies altogether imperceptible SAGR. Though it came not into my thoughts to make triall of these observations when I was at Sea yet am I confident that they will succeed in the same manner as you have related in confirmation of which I remember that being in my Cabbin I have asked an hundred times whether the Ship moved or stood still and sometimes I have imagined that it moved one way when it steered quite another way I am therefore as hitherto satisfied and convinced of the nullity of all those experiments that have been produced in proof of the negative part There now remains the objection founded upon that which experience shews us namely that a swift Vertigo or whirling about hath a faculty to extrude and disperse the matters adherent to the machine that turns round whereupon many were of opinion and Ptolomy amongst the rest that if the Earth should turn round with so great velocity the stones and creatures upon it should be tost into the Skie and that there could not be a morter strong enough to fasten buildings so to their foundations but that they would likewise suffer a like extrusion SALV Before I come to answer this objection I cannot but take notice of that which I have an hundred times observed and not without laughter to come into the minds of most men so soon as ever they hear mention made of this motion of the Earth which is believed by them so fixt and immoveable that they not only never doubted of that rest but have ever strongly believed that all other men aswell as they have held it to be created immoveable and so to have continued through all succeeding ages and being setled in this perswasion they stand amazed to hear that any one should grant it motion as if after that he had held it to be immoveable he had fondly thought it to commence its motion then and not till then when Pythagoras or whoever
Aequinoctial doth move in lesser circles SALV Because so would nay according to the doctrine of Ptolomey so have some fixed stars done which once were very near the Aequinoctial and described very vast circles and now that they are farther off describe lesser SAGR. If I could now but keep in mind all these fine notions I should think that I had made a great purchase I must needs intreat you Simplicius to lend me this Book for there cannot chuse but be a sea of rare and ingenious matters contained in it SIMP I will present you with it SAGR. Not so Sir I would not deprive you of it but are the Queries yet at an end SIMP No Sir hearken therefore Si latio circularis gravibus levibus est naturalis qualis est ea quae fit secundùm lineam rectam Nam si naturalis quomodo is motus qui circum est naturalis est cùm specie differat à recto Si violentus quî fit ut missile ignitum sursum evolans scintillosum caput sursùm à terrâ non autem circum volvatur c. Which take in our idiom If a circular lation is natural to heavy and light things what is that which is made according to a right line For if it be natural how then is that motion which is about the centre natural seeing it differs in species from a right motion If it be violent how is it that a fiery dart flying upwards sparkling over our heads at a distance from the Earth but not turning about c. SALV It hath been said already very often that the circular motion is natural to the whole and to its parts whilst they are in perfect disposure and the right is to reduce to order the parts disordered though indeed it is better to say that neither the parts ordered or disordered ever move with a right motion but with one mixed which might as well be averred meerly circular but to us but one part onely of this motion is visible and observable that is the part of the right the other part of the circular being imperceptible to us because we partake thereof And this answers to the rays which move upwards and round about but we cannot distinguish their circular motion for that with that we our selves move also But I believe that this Author never thought of this mixture for you may see that he resolutely saith that the rays go directly upwards and not at all in gyration SIMP Quare centrum sphaere delapsae sub Aequatore spiram describit in ejus plano sub aliis parallelis spiram describit in cono sub Polo descendit in axe lineam gyralem decurrens in superficie cylindricâ consignatam In English to this purpose Why doth the centre of a falling Globe under the Aequinoctial describe a spiral line in the plane of the Aequator and in other parallels a spiral about a Cone and under the Pole descend in the axis describing a gyral line running in a Cylindrical Superficie SALV Because of the lines drawn from the Centre to the circumference of the sphere which are those by which graves descend that which terminates in the Aequinoctial designeth a circle and those that terminate in other parallels describe conical superficies now the axis describeth nothing at all but continueth in its own being And if I may give you my judgment freely I will say that I cannot draw from all these Queries any sense that interfereth with the motion of the Earth for if I demand of this Author granting him that the Earth doth not move what would follow in all these particulars supposing that it do move as Copernicus will have it I am very confident that he would say that all these effects would happen that he hath objected as inconveniences to disprove its mobility so that in this mans opinion necessary consequences are accounted absurdities but I beseech you if there be any more dispatch them and free us speedily from this wearisom task SIMP In this which follows he opposes Copernicus his Sectators who affirm that the motion of the parts separated from their whole is onely to unite themselves to their whole but that the moving circularly along with the vertigenous diurnal revolution is absolutely natural against which he objecteth saying that according to these mens opinion Si tota terra unà cum aquà in nihilum redigeretur nulla grando aut pluvia è nube decideret sed naturalater tantùm circumferetur neque ignis ullus aut igneum ascenderet cùm illorum non improbabili sententià ignis nullus sit suprà Which I translate to this sense If the whole Earth together with the Water were reduced into nothing no hail or rain would fall from the clouds but would be onely naturally carried round neither any fire or fiery thing would ascend seeing to these that men it is no improbable opinion that there is no fire above SALV The providence of this Philosopher is admirable and worthy of great applause for he is not content to provide for things that might happen the course of Nature continuing but will shew hic care in what may follow from those things that he very well knows shall never come to pass I will grant him therefore that I may get som pretty passages out of him that if the Earth and Water should be reduced to nothing there would be no more hails or rains nor would igneal matters ascend any longer upwards but would continually turn round what will follow what will the Philosopher say then SIMP The objection is in the words which immediately follow here they are Quibus tamen experientia ratio adversatur Which nevertheless saith he is contrary to experience and reason SALV Now I must yield seeing he hath so great an advantage of me as experience of which I am unprovided For as yet I never had the fortune to see the Terrestrial Globe and the element of Water turn'd to nothing so as to have been able to observe what the hail and water did in that little Chaos But he perhaps tells us for our instruction what they did SIMP No he doth not SALV I would give any thing to change a word or two with this person to ask him whether when this Globe vanished it carried away with it the common centre of gravity as I believe it did in which case I think that the hail and water would remain insensate and stupid amongst the clouds without knowing what to do with themselves It might be also that attracted by that great void Vacuum left by the Earths absenting all the ambients would be rarified and particularly the air which is extreme easily drawn and would run thither with very great haste to fill it up And perhaps the more solid and material bodies as birds for there would in all probability be many of them scattered up and down in the air would retire more towards the centre of the great vacant sphere for it
happen to me in the present Probleme for being desirous to assure my self by some other accident whether the reason of the Proposition by me found were true namely whether the substance of the Magnet were really much lesse continuate than that of Iron or of Steel I made the Artists that work in the Gallery of my Lord the Grand Duke to smooth one side of that piece of Magnet which formerly was yours and then to polish and burnish it upon which to my satisfaction I found what I desired For I discovered many specks of colour different from the rest but as splendid and bright as any of the harder sort of stones the rest of the Magnet was polite but to the tact onely not being in the least splendid but rather as if it were smeered over with foot and this was the substance of the Load-stone and the shining part was the fragments of other stones intermixt therewith as was sensibly made known by presenting the face thereof to filings of Iron the which in great number leapt to the Load-stone but not so much as one grain did stick to the said spots which were many some as big as the fourth part of the nail of a mans finger others somewhat lesser the least of all very many and those that were scarce visible almost innumerable So that I did assure my self that my conjecture was true when I first thought that the substance of the Magnet was not close and compact but porous or to say better spongy but with this difference that whereas the sponge in its cavities and little cels conteineth Air or Water the Magnet hath its pores full of hard and heavy stone as appears by the exquisite lustre which those specks receive Whereupon as I have said from the beginning applying the surface of the Iron to the superficies of the Magnet the minute particles of the Iron though perhaps more continuate than these of any other body as its shining more than any other matter doth shew do not all nay but very few of them incounter pure Magnet and the contacts being few the union is but weak But because the cap of the Load-stone besides the contact of a great part of its superficies invests its self also with the virtue of the parts adjoyning although they touch not that side of it being exactly smoothed to which the other face in like manner well polisht of the Iron to be attracted is applyed the contract is made by innumerable minute particles if not haply by the infinite points of both the superficies whereupon the union becometh very strong This observation of smoothing the surfaces of the Irons that are to touch came not into the thoughts of Gilbert for he makes the Irons convex so that their contact is very small and thereupon it cometh to passe that the tenacity wherewith those Irons conjoyn is much lesser SAGR. I am as I told you before little lesse satisfied with this reason that if it were a pure Geometrical Demonstration and because we speak of a Physical Problem I believe that also Simplicius will find himself satisfied as far as natural science admits in which he knows that Geometrical evidence is not to be required SIMP I think indeed that Salviatus with a fine circumlocution hath so manifestly displayed the cause of this effect that any indifferent wit though not verst in the Sciences may apprehend the same but we confining our selves to the terms of Art reduce the cause of these and other the like natural effects to Sympathy which is a certain agreemet and mutual appetite which ariseth between things that are semblable to one another in qualities as likewise on the contrary that hatred enmity for which other things shun abhor one another we call Antipathy SAGR. And thus with these two words men come to render reasons of a great number of accidents and effects which we see not without admiration to be produced in nature But this kind of philosophating seems to me to have great sympathy with a certain way of Painting that a Friend of mine used who writ upon the Tele or Canvasse in chalk here I will have the Fountain with Diana and her Nimphs there certain Hariers in this corner I will have a Hunts-man with the Head of a Stag the rest shall be Lanes Woods and Hills and left the remainder for the Painter to set forth with Colours and thus he perswaded himself that he had painted the Story of Acteon when as he had contributed thereto nothing of his own more than the names But whether are we wandred with so long a digression contrary to our former resolutions I have almost forgot what the point was that we were upon when we fell into this magnetick discourse and yet I had something in my mind that I intended to have spoken upon that subject SALV We were about to demonstrate that third motion ascribed by Copernicus to the Earth to be no motion but a quiescence and maintaining of it self immutably directed with its determinate parts towards the same determinate parts of the Universe that is a perpetual conservation of the Axis of its diurnal revolution parallel to it self and looking towards such and such fixed stars which most constant position we said did naturally agree with every librated body suspended in a fluid and yielding medium which although carried about yet did it not change directionin respect of things external but onely seemed to revolve in its self in respect of that which carryed it round and to the vessel in which it was transported And then we added to this simple and natural accident the magnetick virtue whereby the self Terrestrial Globe might so much the more constantly keep it immutable SAGR. Now I remember the whole businesse and that which then came into my minde which I would have intimated was a certain consideration touching the scruple and objection of Simplicius which he propounded against the mobility of the Earth taken from the multiplicity of motions impossible to be assigned to a simple body of which but one sole and simple motion according to the doctrine of Aristotle can be natural and that which I would have proposed to consideration was the Magnet to which we manifestly see three motions naturally to agree one towards the centre of the Earth as a Grave the second is the circular Horizontal Motion whereby it restores and conserves its Axis towards determinate parts of the Universe and the third is this newly discovered by Gilbert of inclining its Axis being in the plane of a Meridian towards the surface of the Earth and this more and lesse according as it shall be distant from the Equinoctial under which it is parallel to the Axis of the Earth Besides these three it is not perhaps improbable but that it may have a fourth of revolving upon its own Axis in case it were librated and suspended in the air or other fluid and yielding Medium so that
in those that distend themselves for a great length from VVest to East namely according to the course of the motions of the Terrestrial Globe and as it is in a certain manner unthought of and without a president among the motions possible to be made by us so it is not hard for me to believe that effects may be derived from the same which are not to be imitated by our artificial experiments SALV These things being declared it is time that we proceed to examine the particular accidents which together with their diversities are observed by experience in the ebbing and flowing of the waters And first we need not think it hard to guesse whence it happeneth that in Lakes Pooles and also in the lesser Seas there is no notable flux and reflux the which hath two very solid reasons The one is that by reason of the shortnesse of the Vessel in its acquiring in several hours of the day several degrees of velocity they are with very little difference acquired by all its parts for as well the precedent as the subsequent that is to say both the Eastern and VVestern parts do accelerate and retard almost in the same manner and withal making that alteration by little and little and not by giving the motion of the conteining Vessel a sudden check and retardment or a sudden and great impulse or acceleration both it and all its parts come to be gently and equally impressed with the same degrees of velocity from which uniformity it followeth that also the conteined water with but small resistance and opposition receiveth the same impressions and by consequence doth give but very obscure signes of its rising or falling or of its running towards one part or another The which effect is likewise manifestly to be seen in the little artificial Vessels wherein the contained water doth receive the self same impressions of velocity when ever the acceleration and retardation is made by gentle and uniform proportion But in the Straights and Bays that for a great length distend themselves from East to West the acceleration and retardation is more notable and more uneven for that one of its extreams shall be much retarded in motion and the other shall at the same time move very swiftly The reciprocal libration or levelling of the water proceeding from the impetus that it had conceived from the motion of its container The which libration as hath been noted hath its undulations very frequent in small Vessels from whence ensues that though there do reside in the Terrestrial motions the cause of conferring on the waters a motion onely from twelve hours to twelve hours for that the motion of the conteining Vessels do extreamly accelerate and extreamly retard but once every day and no more yet neverthelesse this same second cause depending on the gravity of the water which striveth to reduce it self to equilibration and that according to the shortnesse of the Vessel hath its reciprocations of one two three or more hours this intermixing with the first which also it self in small Vessels is very little it becommeth upon the whole altogether insensible For the primary cause which hath the periods of twelve hours having not made and end of imprinting the precedent commotion it is overtaken and opposed by the other second dependant on the waters own weight which according to the brevity and profundity of the Vessel hath the time of its undulations of one two three four or more hours and this contending with the other former one disturbeth and removeth it not permitting it to come to the height no nor to the half of its motion and by this contestation the evidence of the ebbing and flowing is wholly annihilated or at least very much obscured I passe by the continual alteration of the air which disquieting the water permits us not to come to a certainty whether any though but small encrease or abatement of half an inch or losse do reside in the Straights or receptacles of water not above a degree or two in length I come in the second place to resolve the question why there not residing any vertue in the primary principle of commoving the waters save onely every twelve hours that is to say once by the greatest velocity and once by the greatest tardity of motion the ebbings and flowings should yet neverthelesse appear to be every six hours To which is answered that this determination cannot any wayes be taken from the primary cause onely but there is a necessity of introducing the secondary causes as namely the greater or lesse length of the Vessels and the greater or lesse depth of the waters in them conteined Which causes although they have not any operation in the motions of the waters those operations belonging to the sole primary cause without which no ebbing or flowing would happen yet neverthelesse they have a principal share in determining the times or periods of the reciprocations and herein their influence is so powerful that the primary cause must of force give way unto them The period of six hours therefore is no more proper or natural than those of other intervals of times though indeed its the most observed as agreeing with our Mediterrane which was the onely Sea that for many Ages was navigated though neither is that period observed in all its parts for that in some more angust places such as are the Hellespont and the Aegean Sea the periods are much shorter and also very divers amongst themselves for which diversities and their causes incomprehensible to Aristotle some say that after he had a long time observed it upon some cliffes of Negropont being brought to desperation he threw himself into the adjoyning Euripus and voluntarily drowned himself In the third place we have the reason ready at hand whence it commeth to passe that some Seas although very long as is the Red Sea are almost altogether exempt from Tides which happeneth because their length extendeth not from East to West but rather transversly from the Southeast to the Northwest but the motions of the Earth going from West to East the impulses of the water by that means alwayes happen to fall in the Meridians and do not move from parallel to parallel insomuch that in the Seas that extend themselves athwart towards the Poles and that the contrary way are narrow there is no cause of ebbing and flowing save onely by the participation of another Sea wherewith it hath communication that is subject to great commotions In the fourth place we shall very easily find out the reason why the fluxes and refluxes are greatest as to the waters rising and falling in the utmost extremities of Gulphs and least in the intermediate parts as daily experience sheweth here in Venice lying in the farther end of the Adriatick Sea where that difference commonly amounts to five or six feet but in the places of the Mediterrane far distant from the extreams that mutation is very small as in
for a long tract or distance from West to East that is according to the course of the fluxes and refluxes therefore in this the agitations are very great and would be much more violent between Hercules Pillars in case the Straight of Gibraltar did open lesse and those of the Straight of Magellanes are reported to be extraordinary violent This is what for the present cometh into my mind to say unto you about the causes of this first period diurnal of the Tide and its various accidents touching which if you have any thing to offer you may let us hear it that so we may afterwards proceed to the other two periods monethly and annual SIMP In my opinion it cannot be denied but that your discourse carrieth with it much of probability arguing as we say ex suppositione namely granting that the Earth moveth with the two motions assigned it by Copernicus but if that motion be disproved all that you have said is vain and insignificant and for the disproval of that Hypothesis it is very manifestly hinted by your Discourse it self You with the supposition of the two Terrestrial motions give a reason of the ebbing and flowing and then again arguing circularly from the ebbing and flowing draw the reason and confirmation of those very motions and so proceeding to a more specious Discourse you say that the Water as being a fluid body and not tenaciously annexed to the Earth is not constrained punctually to obey every of its motions from which you afterwards infer its ebbing and flowing Now I according to your own method argue the quite contrary and say the Air is much more tenuous and fluid than the Water and lesse annexed to the Earths superficies to which the Water if it be for nothing else yet by reason of its gravity that presseth down upon the same more than the light Air adhereth therefore the Air is much obliged to follow the motions of the Earth and therefore were it so that the Earth did move in that manner we the inhabitants of it and carried round with like velocity by it ought perpetually to feel a Winde from the East that beateth upon us with intolerable force And that so it ought to fall out quotidian experience assureth us for if with onely riding post at the speed of eight or ten miles an hour in the tranquil Air the incountering of it with our face seemeth to us a Winde that doth not lightly blow upon us what should we expect from our rapid course of 800. or a thousand miles an hour against the Air that is free from that motion And yet notwithstanding we cannot perceive any thing of that nature SALV To this objection that hath much of likelihood in it I reply that its true the Air is of greater tenuity and levity and by reason of its levity lesse adherent to the Earth than Water so much more grave and bulky but yet the consequence is false that you infer from these qualities namely that upon account of that its levity tenuity and lesse adherence to the Earth it should be more exempt than the Water from following the Terrestrial Motions so as that to us who absolutely pertake of of them the said exemption should be sensible and manifest nay it happeneth quite contrary for if you well remember the cause of the ebbing and flowing of the Water assigned by us consisteth in the Waters not following the unevennesse of the motion of its Vessel but retaining the impetus conceived before without diminishing or increasing it according to the precise rate of its diminishing or increasing in its Vessel Because therefore that in the conservation and retention of the impetus before conceived the disobedience to a new augmentation or diminution of motion consisteth that moveable that shall be most apt for such a retention shall be also most commodious to demonstrate the effect that followeth in consequence of that retention Now how much the Water is disposed to maintain such a conceived agitation though the causes cease that impress the same the experience of the Seas extreamly disturbed by impetuous Winds sheweth us the Billows of which though the Air be grown calm and the Wind laid for a long time after continue in motion As the Sacred Poet pleasantly sings Qual l'alto Egeo c. And that long continuing rough after a storm dependeth on the gravity of the water For as I have elsewhere said light bodies are much easier to be moved than the more grave but yet are so much the less apt to conserve the motion imparted when once the moving cause ceaseth Whence it comes that the Aire as being of it self very light and thin is easily mov'd by any very small force yet it is withall very unable to hold on its motion the Mover once ceasing Therefore as to the Aire which environs the Terrestrial Globe I would fay that by reason of its adherence it is no lesse carried about therewith then the Water and especially that part which is contained in its vessels which vessels are the valleys enclosed with Mountains And we may with much more reason affirm that this same part of the Air is carried round and born forwards by the rugged parts of the Earth than that the higher is whirl'd about by the motion of the Heavens as ye Peripateticks maintain What hath been hitherto spoken seems to me a sufficient answer to the allegation of Simplitius yet nevertheless with a new instance and solution founded upon an admirable experiment I will superabundantly satisfie him and confirm to Sagredus the mobility of the Earth I have told you that the Air and in particular that part of it which ascendeth not above the tops of the highest Mountains is carried round by the uneven parts of the Earths surface from whence it should seem that it must of consequence come to passe that in case the superficies of the Earth were not uneven but smooth and plain no cause would remain for drawing the Air along with it or at least for revolving it with so much uniformity Now the surface of this our Globe is not all craggy and rugged but there are exceeding great tracts very even to wit the surfaces of very vast Seas which being also far remote from the continuate ledges of Mountains which environ it seem to have no faculty of carrying the super-ambient Air along therewith and not carrying it about we may perceive what will of consequence ensue in those places SIMP I was about to propose the very same difficulty which I think is of great validity SALV You say very well Simplicius for from the not finding in the Air that which of consequence would follow did this our Globe move round you argue its immoveablenesse But in case that this which you think ought of necessary consequence to be found be indeed by experience proved to be so will you accept it for a sufficient testimony and an argument for the mobility of
the said Globe SIMP In this case it is not requisite to argue with me alone for if it should so fall out and that I could not comprehend the cause thereof yet haply it might be known by others SALV So that by playing with you a man shall never get but be alwayes on the losing hand and therefore it would be better to give over Nevertheless that we may not cheat our third man we will play on We said even now and with some addition we reitterate it that the Ayr as if it were a thin and fluid body and not solidly conjoyned with the Earth seem'd not to be necessitated to obey its motion unlesse so far as the cragginess of the terrestrial superficies transports and carries with it a part thereof contigious thereunto which doth not by any great space exceed the greatest altitude of Mountains the which portion of Air ought to be so much less repugnant to the terrestrial conversion by how much it is repleat with vapours fumes and exhalations matters all participating of terrene qualities and consequently apt of their own nature to the same motions But where there are wanting the causes of motion that is where the surface of the Globe hath great levels and where there is less mixture of the terrene vapours there the cause whereby the ambient Air is constrained to give entire obedience to the terrestrial conversion will cease in part so that in such places whilst the Earth revolveth towards the East there will be continually a wind perceived which will beat upon us blowing from the East towards the West and such gales will be the more sensible where the revolution of the Globe is most swift which will be in places more remote from the Poles and approaching to the greatest Circle of the diurnal conversion But now de facto experience much confirmeth this Phylosophical argumentation for in the spatious Seas and in their parts most remote from Land and situate under the Torrid Zone that is bounded by the Tropicks where there are none of those same terrestrial evaporations we finde a perpetual gale move from the East with so constant a blast that ships by favour thereof sail prosperously to the West-India's And from the same coasting along the Mexican shore they with the same felicity pass the Pacifick Ocean towards the India's which to us are East but to them are West Whereas on the contrary the Course from thence towards the East is difficult and uncertain and not to be made by the same Rhumb but must vere more to Land-ward to recover other Winds which we may call accidentary and tumultuary produced from other Principles as those that inhabit the continent find by experience Of which productions of Winds the Causes are many and different which shall not at this time be mentioned And these accidentary Winds are those which blow indifferently from all parts of the Earth and make rough the Seas remote from the Equinoctial and environed by the rugged Surface of the Earth which is as much as to say environ'd with those perturbations of Air that confound that primary Gale The which in case these accidental impediments were removed would be continually felt and especially upon the Sea Now see how the effect of the Water and Air seem wonderfully to accord with the Celestial observations to confirm the mobility of our Terrestrial Globe SAGR. I also for a final close will relate to you one particular which as I believe is unknown unto you and which likewise may serve to confirm the same conclusion You Salviatus alledged That Accident which Sailers meet with between the Tropicks I mean that perpetual Gale of Winde that beats upon them from the East of which I have an account from those that have many times made the Voyage And moreover which is very observable I understand that the Mariners do not call it a Wind but by another name which I do not now remember taken haply from its so fixed and constant Tenor which when they have met with they tie up their shrouds and other cordage belonging to the Sails and without any more need of touching them though they be in a sleep they can continue their course Now this constant Trade-wind was known to be such by its continual blowing without interruptions for if it were interrupted by other Windes it would not have been acknowledged for a singular Effect and different from the rest from which I will infer That it may be that also our Mediterranean Sea doth partake of the like accident but it is not observed as being frequently altered by the confluence of other windes And this I say not without good grounds yea upon very probable conjectures whch came unto my knowledge from that which tendred it self to my notice on occasion of the voyage that I made into Syria going Consul for this Nation to Aleppo and this it is That keeping a particular account and memorial of the dayes of the departure and arrival of the Ships in the Ports of Alexandria of Alexandretta and this of Venice in comparing sundry of them which I did for my curiosity I found that in exactness of account the returns hither that is the voiages from East to West along the Mediterrane are made in less time then the contrary courses by 25. in the Hundred So that we see that one with another the Eastern windes are stronger then the Western SALV I am very glad I know this particular which doth not a little make for the confirmation of the Earths mobility And although it may be alledged That all the Water of the Mediterrane runs perpetually towards the Straits-mouth as being to disimbogue into the Ocean the waters of as many Rivers as do discharge themselves into the same I do not think that that current can be so great as to be able of it self alone to make so notable a difference which is also manifest by observing that the water in the Pharo of Sicily runneth back again no less towards the East than it runneth forwards towards the West SAGR. I that have not as Simplicius an inclination to satisfie any one besides my self am satisfied with what hath been said as to this first particular Therefore Salviatus when you think it sit to proceed forward I am prepared to hear you SALV I shall do as you command me but yet I would fain hear the opinion also of Simplicius from whose judgement I can argue how much I may promise to my self touching these discourses from the Peripatetick Schools if ever they should come to their ears SIMP I desire not that my opinion should serve or stand for a measure whereby you should judge of others thoughts for as I have often said I am inconsiderable in these kinde of studies and such things may come into the mindes of those that are entered into the deepest passages of Philosophy as I could never think of as having according to the Proverb
scarce kist her Maid yet nevertheless to give you my sudden thoughts I shall tell you That of those effects by you recounted and particularly the last there may in my judgement very sufficient Reasons be given without the Earths mobility by the mobility of the Heavens onely never introducing any novelty more than the inversion of that which you your self propose unto us It hath been received by the Peripatetick Schools that the Element of Fire and also a great part of the Aire is carried about according to the Diurnal conversion from East to West by the contact of the Concave of the Lunar Orb as by the Vessel their container Now without going out of your track I will that we determine the Quantity of the Aire which partaketh of that motion to distend so low as to the Tops of the highest Hills and that likewise they would reach to the Earth if those Mountains did not impede them which agreeth with what you say For as you affirm the Air which is invironed by ledges of Mountains to be carried about by the asperity of the moveable Earth we on the contrary say That the whole Element of Air is carried about by the motion of Heaven that part only excepted which lyeth below those bodies which is hindred by the asperity of the immoveable Earth And whereas you said That in case that asperity should be removed the Air would also cease to be whirld about we may say That the said asperity being removed the whole Aire would continue its motion Whereupon because the surfaces of spacious Seas are smooth and even the Airs motion shall continue upon those alwaies blowing from the East And this is more sensibly perceived in Climates lying under the Line and within the Tropicks where the motion of Heaven is swifter and like as that Celestial motion is able to bear before it all the Air that is at liberty so we may very rationally affirm that it contributeth the same motion to the Water moveable as being fluid and not connected to the immobility of the Earth And with so much the more confidence may we affirm the same in that by your confession that motion ought to be very small in resect of the efficient Cause which begirting in a natural day the whole Terrestrial Globe passeth many hundreds of miles an hour and especially towards the Equinoctial whereas in the currents of the open Sea it moveth but very few miles an hour And thus the voiages towards the West shall come to be commodious and expeditious not onely by reason of the perpetual Eastern Gale but of the course also of the Waters from which course also perhaps the Ebbing and Flowing may come by reason of the different scituation of the Terrestrial Shores against which the Water coming to beat may also return backwards with a contrary motion like as experience sheweth us in the course of Rivers for according as the Water in the unevenness of the Banks meeteth with some parts that stand out or make with their Meanders some Reach or Bay here the Water turneth again and is seen to retreat back a considerable space Upon this I hold That of those effects from which you argue the Earths mobility and alledge it as a cause of them there may be assigned a cause sufficiently valid retaining the Earth stedfast and restoring the mobility of Heaven SALV It cannot be denied but that your discourse is ingenious hath much of probability I mean probability in appearance but not in reality existence It consisteth of two parts In the first it assignes a reason of the continual motion of the Eastern Winde and also of a like motion in the Water In the second It would draw from the same Sourse the cause of the Ebbing and Flowing The first part hath as I have said some appearance of probability but yet extreamly less then that which we take from the Terrestrial motion The second is not onely wholly improbable but altogether impossible and false And coming to the first whereas it is said that the Concave of the Moon carrieth about the element of Fire and the whole Air even to the tops of the higher Mountains I answer first that it is dubious whether there be any element of Fire But suppose there be it is much doubted of the Orbe of the Moon as also of all the rest that is Whether there be any such solid bodies and vast or elss Whether beyond the Air there be extended a continuate expansion of a substance of much more tenuity and purity than our Air up and down which the Planets go wandring as now at last a good part of those very Phylosophers begin to think But be it in this or in that manner there is no reason for which the Fire by a simple contract to a superficies which you your self grant to be smooth and terse should be according to its whole depth carried round in a motion different from its natural inclination as hath been defusely proved and with sensible reasons demonstrated by Il Saggiatore Besides the other improbability of the said motions transfusing it self from the subtilest Fire throughout the Air much more dense and from that also again to the Water But that a body of rugged and mountainous surface by revolving in it self should carry with it the Air contiguous to it and against which its promontaries beat is not onely probable but necessary and experience thereof may be daily seen though without seeing it I believe that there is no judgement that doubts thereof As to the other part supposing that the motion of Heaven did carry round the Air and also the Water yet would that motion for all that have nothing to do with the Ebbing and Flowing For being that from one onely and uniform cause there can follow but one sole and uniform effect that which should be discovered in the Water would be a continuate and uniform course from East to West and in that a Sea onely which running compass environeth the whole Globe But in determinate Seas such as is the Mediterrane shut up in the East there could be no such motion For if its Water might be driven by the course of Heaven towards the West it would have been dry many ages since Besides that our Water runneth not onely towards the West But returneth backwards towards the East and that in ordinal Periods And whereas you say by the example of Rivers that though the course of the Sea were Originally that onely from East to West yet nevertheless the different Position of the Shores may make part of the Water regurgitate and return backwards I grant it you but it is necessary that you take notice my Simplicius that where the Water upon that account returneth backwards it doth so there perpetually and where it runneth straight forwards it runneth there alwayes in the same manner for so the example of the Rivers shewes you But in the case
Earth answered by Examples of the like Motions in other Celestial Bodies 236 A fourth Argument of Claramontius against the Copernican Hypothesis of the Earths Mobility 239 From the Earths obscurity and the splendor of the fixed Stars it is argued that it is moveable and they immoveable 239 A fifth Argument of Claramontius against the Copernican Hypothesis of the Earths Mobility 240 Another difference between the Earth and Celestial Bodies taken from Purity and impurity 240 It seems a Solecisme to affirme that the Earth is not in Heaven 241 Granting to the Earth the Annual it must of necessity also have the Diurnal Motion assigned to it 300 Discourses more than childish that serve to keep Fools in the Opinion of the Earths Stability 301 The Difficulties removed that arise from the Earths moving about the Sun not solitarily but in consort with the Moon 307 The Axis of the Earth continueth alwayes parallel to it self and describeth a Cylindraical Superficies inclining to the Orb. 344 The Orb of the Earth never inclineth but is immutably the same 345 The Earth approacheth or recedeth from the fixed Stars of the Ecliptick the quantity of the Grand Orb. 349 If in the fixed Stars one should discover any Mutation the Motion of the Earth would be undeniable 351 Necessary Propositions for the better conceiving of the Consequences of the Earths Motion 354 An admirable Accident depending on the not-inclining of the Earths Axis 358 Four several Motions assigned to the Earth 362 The third Motion ascribed to the Earth is rather a resting immoveable 363 An admirable interne vertue or faculty of the Earths Globe to behold alwayes the same part of Heaven 363 Nature as iâ— sport maketh the Ebbing and Flowing of the Sea to prove the Earths Mobility 379 All Terrene Effects indifferently confirm the Motion or Rest of the Earth except the Ebbing and Flowing of the Sea 380 The Cavities of the Earth cannot approach or recede from the Centre of the same 387 The Hypothesis of the Earths Mobility taken in favour of the Ebbing and Flowing opposed 399 The Answers to those Objections made against the Earths Motion 399 The Revolution of the Earth confirmed by a new Argument taken from the Aire 400 The vaporous parts of the Earth partake of its Motions 400 Another observation taken from the Ayr in confirmation of the motion of the Earth 402 A Reason of the continual Motion of the Air and Water may be given by making the Earth moveable rather then by making it immoveable 405 The Earths Mobility held by sundry great Philosophers amongst the Antients 437 468 The Fathers agree not in expounding the Texts of Scripture that are alledged against the Earths Mobility 450 The Earth Mobility defended by many amongst the Modern Writers 478 The Earth shall stand still after the Day of Judgement 480 The Earth is another Moon or Star 486 The Earths several Motions according to Copernicus 491 The Earth secundum totum is Immutable though not Immoveable 491 The Earths Natural Place 492 The Earths Centre keepeth her in her Natural Place 493 The Earth in what Sense it may absolutely be said to be in the lowest part of the World 496 EBBING and Ebbings The first general Conclusion of the impossibility of Ebbing and Flowing the Immobility of the Terrestrial Globe being granted 380 The Periods of Ebbings and Flowings Diurnal Monethly and Annual 381 Varieties that happen in the Diurnal Period of the Ebbings and Flowings 382 The Causes of Ebbings and Flowings alledged by a Modern Phylosopher 382 The Cause of the Ebbing and Flowing ascribed to the Moon by a certain Prelate 383 The Cause of the Ebbing c. referred by Hyeronimus Borrius and other Peripateticks to the temperate heat of the Moon 383 Answers to the Vanities alledged as Causes of the Ebbing and Flowing 383 It s proved impossible that there should naturally be any Ebbing and Flowing the Earth being immoveable 386 The most potent and primary Cause of the Ebbing and Flowing 390 Sundry accidents that happen in the Ebbings and Flowings 391 Reasons renewed of the particular Accidents observed in the Ebbings and Flowings 393 Second Causes why in several Seas and Lakes there are no Ebbings and Flowings 394 The Reason why the Ebbings and Flowings for the most part are every Six Hours 395 The Cause why some Seas though very long suffer no Ebbing and Flowing 395 Ebbings and Flowings why greatest in the Extremities of Gulphs and least in the middle parts 396 A Discussion of some more Abstruce Accidents observed in the Ebbing and Flowing 396 The Ebbing and Flowing may depend on the Diurnal Motion of Heaven 404 The Ebbing and Flowing cannot depend on the Motion of Heaven 405 The Causes of the Periods of the Ebbings and Flowings Monethly and Annual at large assigned 407 The Monethly and Annual alterations of the Ebbings and Flowings can depend on nothing save on the alteration of the Additions and Subtractions of the Diurnal Period from the Annual 408 Three wayes of altering the proportion of the Additions of the Diurnal Revolution to the Annual Motion of the Ebbing and Flowing 409 Ebbings and Flowings are petty things in comparison of the vastnesse of the Seas and the Velocity of the Motion of the Terrestrial Globe 417 EFFECT and Effects Of a new Effect its necessary that the Cause be likewise new 370 The Knowledge of the Effects contribute to the investigation of the Causes 380 True and Natural Effects follow without difficulty 387 Alterations in the Effects argue alteration in the Cause 407 ELEMENTS and their Motions Vide MOTION ENCYCLOPEDIA Subtilties sufficiently insipid ironically spoken and taken from a certain Encyclopedia 153 EXPERIMENTS Sensible Experiments are to be preferred before Humane Argumentations 21 33 42. It is good to be very cautious in admitting Experiments for true to those that never tryed them 162 Experiments and Arguments against the Earths Motion seem so far concluding as they lye under Equivokes 162 The Authority of Sensible Experiments and necessary Demonstrations in deciding of Physical Controversies 436 EYE The Circle of the Pupil of the Eye contracteth and enlargeth 329 How to finde the distance of the Rays Concourse from the Pupil of the Eye 329 F FAITH Faith more infallible than either Sense or Reason 475 FIRE Fire moveth directly upwards by Nature and round about by Participation according to Aristotle 122 It is improbable that the Element of Fire should be carried round by the Concave of the Moon 405 FIGURE and Figures Figure is not the Cause of Incorruptibility but of Longer Duration 66 The perfection of Figure appeareth in Corruptible Bodies but not in the Eternal 69 If the Spherical Figure conferred Eternity all things would be Eternal 69 It is more difficult to finde Figures that touch in a part of their Surface then in one sole point 185 The Circular Figure placed amongst the Postulata of Mathematicians 186 Irregular Figures and Formes difficult to be introduced 187 Superficial figures increase in proportion
Therefore neither the whole Earth nor the whole Water nor the whole Air can secundum totum be driuen or forced out of their proper place site or Systeme in the Universe in respect of the order and disposition of other mundane Bodies And thus there is no Star though Erratick Orb or Sphere that can desert its natural place although it may otherwise have some kind of motion Therefore all things how moveable soever are notwithstanding said to be stable and immoveable in their proper place according to the foresaid sense i.e. secundum totum For nothing hinders but that secundum partes they may some waymove which motion shall not be natural but violent Therefore the Earth although it should be moveable yet it might be said to be immoveable according to the precedent Maxime for that its neither moved in a right Motion nor out of the Course assigned it in its Creation for the standing Rule of its motion but keep within its own site being placed in that which is called the Grand Orb above Venus and beneath Mars and being in the middle betwixt these which according to the common opinion is the Suns place it equally and continually moveth about the Sun and the two other intermediate Planets namely Venus and Mercury and hath the Moon which is another Earth but Aetherial as Macrobius after some of the ancient Philosophers will have it about it self From whence inasmuch as she persisteth uniformly in her Course and never at any time departeth from it she may be said to be stable and immoveable and in the same sense Heaven likewise with all the Elements may be said to be immoveable The fifth Maxime followeth being little different from the former Amongst the things created by God some are of such a nature that their parts may be ab invicem or by turns separated from themselves and dis-joyned from their Whole others may not at least taken collectively now those are perishable but these perpetual The Earth therefore since it is reckoned amongst those things that are permanent as hath been said already hath its parts not dissipable nor ab invicem separable from its Centre whereby its true and proper place is assigned it and from its whole taken collectively because according to its whole it is always preserved compact united and cohaerent in it self nor can its parts be seperated from the Centre or from one another unless it may so fall out per accidens and violently in some of its parts which afterwards the obstacle being removed return to their Natural Station spontaneously and without any impulse In this Sense therefore the Earth is said to be Immoveable and Immutable yea even the Sea Aire Heaven and any other thing although otherwise moveable so long as its parts are not dissipable and seperable may be said to be Immoveable at last taken collectively This Principle or Maxim differeth from the precedent only in that this referrs to the parts in order to Place and this in order to the Whole From this Speculation another Secret is discovered For hence it is manifest wherein the proper and genuine formality of the Gravity aad Levity of Bodyes consisteth a point which is not so clearly held forth nor so undeniably explained by the Peripatetick Phylosophy Gravity therefore is nothing else according to the Principles of this new Opinion than a certain power and appetite of the Parts to rejoyn with their Whole and there to rest as in their proper place Which Faculty or Disposition is by Divine Providence bestowed not only on the Earth and Terrene Bodies but as is believed on Coelestial Bodies also namely the Sun Moon and Stars all whose parts are by this Impulsion connected and conserved together cleaving closely to each other and on all sides pressing towards their Centre until they come to rest there From which Concourse and Compression a Sphaerical and Orbicular Figure of the Caelestial Orbes is produced wherein by this occult Quality naturally incident to each of them they of themselves subsist and are alwayes preserved But Levity is the Extrusion and Exclusion of a more tenuose and thin Body from the Commerce of one more Solid and dense that is Heterogeneal to it by vertue of Heat Whereupon as the Motion of Grave Bodies is Compressive so the Motion of Light Bodies is Extensive For it s the propperty of Heat to dilate and rarify those things to which it doth apply conjoine and communicate it self And for this reason we find Levity and Gravity not only in respect of this our Terestrial Globe and the Bodies adjacent to it but also in respect of those Bodies which are said to be in the Heavens in which those parts which by reason of their proclivity make towards their Centre are Grave and those that incline to the Circumference Light And so in the Sun Moon and Starrs there are parts as well Grave as Light And consequently Heaven it self that so Noble Body and of a fifth Essence shall not be constituted of a Matter different from that of the Elements being free from all Mutation in it's Substance Quantity and Quality Nor so admirable and excellent as Aristotle would make us to believe nor yet a solid Body and impermeable and much lesse as the generality of men verily believe of an impenetrable and most obdurate Density but in it as this Opinion will have it Comets may be generated and the Sun it self as t is probable exhaling or attracting sundry vapours to the surface of its Body may perhaps produce those Spots which were observed to be so various and irregular in its Discus of which Galilaeus in a perticular Treatise hath most excellently and most accurately spoken insomuch that though it were not besides my present purpose yet it is convenient that I forbear to speak any thing touching those matters least I should seem to do that which he hath done before me But now if there be found in the Sacred Scriptures any Authority contrary to these things it may be salved by the foresaid Arguments Analogically applyed And furthermore it may be said that that Solidity is to be so understood as that it admits of no vacuum cleft or penetration from whence the least vacuity might proceed For the truth is as that cannot be admitted in bodily Creatures so it is likewise repugnant to Heaven it self being indeed a Body of its own Nature the most Rare of all others and tenuose beyond all Humane Conception and happly hath the same proportion to the Aire as the Aire to the Water It is clear also from these Principles how false these words of Aristotle are that Of one simple Body there is one simple Motion and this is of two kindes Right and Circular the Right is twofold from the medium and to the medium the first of Light Bodyes as the Aire and Fire the second of Grave Bodyes as the Water and Earth the Circular which is about the
were therein altogether unconcerned Moreover in the fourth place we must note That it might so fall out that such a River not onely was uninteressed in the Innundation though augmented in measure but it might I say happen that it was instrumental to the asswaging the Innundation by augmenting in the measure of its own Channel which matter is sufficiently evident for if it be supposed that the River in the time of flood had not had of it self and from its proper springs more Water than ordinary it s a thing certain that the Water of Tiber rising and increasing also that River to level it self with the Water of Tiber would have retained some of its Waters in its own Chanel without discharging them into Tyber or else would have ingorged and swallowed if I may so say some of the water of Tyber and in this case at the time of Inundation lesse abundance of water would have come to Rome and yet neverthelesse the measure of that River would have been increased Fifthly Fontana deceiveth himself when he concludeth that to remove the Inundation from Rome it would be necessary to make two other Chanels of Rivers that were as large as that which is the present one and that less would not suffice which I say is a fallacy and to convince him easily of his errour it sufficeth to say that all the Streams being passed under the Bridge Quattro-Capi as he himself attests a Channel would suffice only of the capacity of the said Bridge provided that the water there might run with the same velocity as it did under the Bridge at the time of Inundation and on the contrary twenty Currents of capacity equal to the present one would not suffice if the water should run with twenty times less velocity than it made at the time of the Inundation Sixthly to me it seemeth a great weaknesse to say that there should passe under the Bridge Quattro-Capi an hundred fifty one ells of water compressed for that I do not understand that water is like Cotton or Wool which matters may be prest and trod as it happeneth also to the air which receiveth compression in such sort that after that in some certain place a quantity of air shall be reduced to its natural constitution and having taken up all the said place yet neverthelesse compressing the first Air with force and violence it is reduced into far less room and will admit four or six times as much air as before as is experimentally seen in the Wind-Gun invented in our dayes by M. Vincenzo Vincenti of Vrbin which property of the Air of admitting condensation is also seen in the portable Fountains of the same M. Vincenzo which Fountains spirt the Water on high by force of the Air compressed which whilst it seeks to reduce its self to its natural constitution in the dilation causeth that violence But the water can never for any thing I know crowd or press so as that if before the compression it held or possest a place being in its natural constitution I believe not I say that it is possible by pressing and crowding to make it possess less room for if it were possible to compress the Water and make it to occupy a less place it would thence follow that two Vessels of equal measure but of unequal height should be of unequal capacity and that should hold more water which was higher also a Cylinder or other Vessel more high than broad would containe more water erected than being laid along for that being erected the water put therein would be more pressed and crowded And therefore in our case according to our principles we will say that the water of that Stream passeth all under the said Bridge Quattro-Capi for that being there most swift it ought of consequence to be less in measure And here one may see into how many errours a man may run through ignorance of a true and real Principle which once known and well understood takes away all mists of doubting and easily resolveth all difficulties COROLLARIE XII THrough the same inadvertency of not regarding the variation of velocity in the same Current there are committed by Ingineers and Learned men errours of very great moment and I could thereof produce examples but for good reasons I pass them over in silence when they think and propose by deriving new Channels from great Rivers to diminish the measure of the water in the River and to diminish it proportionally according to the measure of the Water which they make to pass through the Channel as making v. g. a Channel fifty foot broad in which the derived water is to run waste ten foot deep they think they have diminished the measure of the Water in the River five hundred feet which thing doth not indeed so fall out and the reason is plain for that the Chanel being derived the rest of the main River diminisheth in velocity and therefore retains a greater measure than it had at first before the derivation of the Chanel and moreover if the Chanel being derived it shall not conserve the same velocity which it had at first in the main River but shall diminish it it will be necessary that it hath a greater measure than it had before in the River and therefore to accompt aright there shall not be so much water derived into the Channel as shall diminish the River according to the quantity of the water in the Channel as is pretended COROLLARIE XIII THis same consideration giveth me occasion to discover a most ordinary errour observed by me in the businesse of the water of Ferara when I was in those parts in service of the most Reverend and Illustrious Monsignor Corsini the sublime wit of whom hath been a very great help to me in these contemplations it s very true I have been much perplexed whether I should commit this particular to paper or passe it over in silence for that I have ever doubted that the opinion so common and moreover confirmed with a most manifest experiment may not onely make this my conjecture to be esteemed far from true but also to discredit with the World the rest of this my Treatise Neverthelesse I have at last resolved not to be wanting to my self and to truth in a matter of it self and for other consequences most important nor doth it seem to me requisite in difficult matters such as these we have in hand to resigne our selves to the common opinion since it would be very strange if the multitude in such matters should hit on the truth nor ought that to be held difficult in which even the vulgar do know the truth and right besides that I hope morever to prove all in such sort that persons of solid judgment shall rest fully perswaded so that they but keep in mind the principal ground and foundation of all this Treatise and though that which I will propose be a particular as I have said pertaining onely to the interests of
prejudice of all the places and villages circumjacent in regard that the Water which used to run from the said Lake turned 22 Mills which not going necessitated the inhabitants of those parts to go a dayes journey and more to grinde upon the Tiber. Being returned to Perugia there followed a Rain not very great but constant and even which lasted for the space of eight hours or thereabouts and it came into my thoughts to examine being in Perugia how much the Lake was increased and raised by this Rain supposing as it was probable enough that the Rain had been universal over all the Lake and like to that which fell in Perugia and to this purpose I took a Glasse formed like a Cylinder about a palme high and half a palme broad and having put in water sufficient to cover the bottome of the Glasse I noted diligently the mark of the height of the Water in the Glasse and afterwards exposed it to the open weather to receive the Raine-water which fell into it and I let it stand for the space of an hour and having observed that in that time the Water was risen in the Vessel the height of the following line I considered that if I had exposed to the same rain such other vessels equal to that the Water would have risen in them all according to that measure And thereupon concluded that also in all the whole extent of the Lake it was necessary the Water should be raised in the space of an hour the same measure Yet here I considered two difficulties that might disturb and altar such an effect or at least render it inobserveable which afterwards well weighed and resolved left me as I will tell you anon in the conclusion the more confirmed that the Lake ought to be increased in the space of eight hours that the rain lasted eight times that measure And whilst I again exposed the Glass to repeat the experiment there came unto me an Ingeneer to talk with me touching certain affairs of our Monastary of Perugia and discoursing with him I shewed him the Glass out at my Chamber-window exposed in a Court-yard and communicated to him my fancy relating unto him all that I had done But I soon perceived that this brave fellow conceited me to be but of a dull brain for he smiling said unto me Sir you deceive your self I am of opinion that the Lake will not be increased by this rain so much as the thicknesse of Julio Hearing him pronounce this his opinion with freeness and confidence I urged him to give me some reason for what he said assuring him that I would change my judgement when I saw the strength of his Arguments To which he answered that he had been very conversant about the Lake and was every day upon it and was well assured that it was not at all increased And importuning him further that he would give me some reason for his so thinking he proposed to my consideration the great drought passed and that that same rain was nothing for the great parching To which I answered I believe Sir that the surface of the Lake on which the rain had fallen was moistned and therefore saw not how its drought which was nothing at all could have drunk up any part of the rain For all this he persisting in his conceit without yielding in the least to my allegation he granted in the end I believe in civility to me that my reason was plausible and good but that in practise it could not hold At last to clear up all I made one be called and sent him to the mouth of the Emissary of the Lake with order to bring me an exact account how he found the water of the Lake in respect of the Transome of the Sluice Now here Signore Galilaeo I would not have you think that I had brought the matter in hand to concern me in my honour but believe me and there are witnesses of the same still living that my messenger returning in the evening to Perugia he brought me word that the water of the Lake began to run through the Cave and that it was risen almost a fingers breadth above the Transome Insomuch that adding this measure to that of the lowness of the surface of the Lake beneath the Transome before the rain it was manifest that the rising of the Lake caused by the rain was to a hair those four fingers breadth that I had judged it to be Two dayes after I had another bout with the Ingeneer and related to him the whole business to which he knew not what to answer Now the two difficulties which I thought of able to impede my conclusion were these following first I considered that it might be that the Wind blowing from the side where the Sluice stood to the Lake-ward the mole and mass of the Water of the Lake might be driven to the contrary shore on which the Water rising it might be fallen at the mouth of the Emissary and so the observation might be much obscured But this difficulty wholly vanished by reason of the Aires great tranquility which it kept at that time for no Wind was stirring on any side neither whilst it rained nor afterwards The second difficulty which put the rising in doubt was That having observed in Florence and elsewhere those Ponds into which the rain-rain-water falling from the house is conveyed through the Common-shores And that they are not thereby ever filled but that they swallow all that abundance of water that runs into them by those conveyances which serve them with water insomuch that those conveyances which in time of drought maintain the Pond when there come new abundance of water into the Pond they drink it up and swallow it A like effect might also fall out in the Lake in which there being many veins as it is very likely that maintain and feed the Lake these veins might imbibe the new addition of the Rain-water and so by that means annull the rising or else diminish it in such sort as to render it inobservable But this difficulty was easily resolved by considering my Treatise of the measure of Running-Waters forasmuch as having demonstrated that the abatement of a Lake beareth the reciprocal proportion to the velocity of the Emissary which the measure of the Section of the Emissary of the Lake hath to the measure of the surface of the Lake making the calculation and account though in gross by supposing that its veins were sufficiently large and that the velocity in them were notable in drinking up the water of the Lake yet I found nevertheless that many weeks and moneths would be spent in drinking up the new-come abundance of water by the rain so that I rested sure that the rising would ensue as in effect it did And because many of accurate judgement have again caused me to question this rising setting before me that the Earth being parched by the great drought that had so long continued it
bring such a drift of sand into the Ports that if it doth not wholly choke them up it shall render them at least unprofitable and impossible for Barks and great Vessels Many other considerations might be propounded concerning these two heads of the stoppage of the Ports and of the appearance of the Ouze and Mud in the Lakes but so much shall suffice us to have hinted to make way for discoursing of the operations about the oportune remedies Yet before that I propound my opinion I say That I know very well that my proposal at first sight will seem absurd and inconvenient and therefore as such will perhaps be rejected by the most and so much the rather for that it will prove directly contrary to what hath hitherto been and as I hear is intended to be done And I am not so wedded to my opinions but that I do consider what others may judge thereof But be it as it will I am obliged to speak my thoughts freely and that being done I will leave it to wiser men than my sâ—lf when they shall have well considered my reasons to judge and deliberate of the quid agendum And if the sentence shall go against me I appeal to the most equitable and inexorable Tribunal of Nature who not caring in the least to please either one party or another will be alwaies a punctual and inviolable executrix of her eternal Decrees against which neither humane deliberations nor our vain desires shall ever have power to rebell I added by word of mouth that which followeth Though your Highness interest your self in this Noble Colledge and cause it to be confirmed in the Senate by universal Vote that the Winds do not blow that the Sea doth not fluctuate that the Rivers do not run yet shall the Winds be alwaies deaf the Sea shall be constant in its inconstancy and the Rivers most obstinate And these shall be my Judges and to their determination I refer my self By what hath been said in my opinion that is made very clear and manifest which in the beginning of this discourse I glanced at namely That the whole disorder although it be divided into two heads into the discovery of the Mud and of the stoppage Ports yet nevertheless by the application of one onely remedy and that in my esteem very easie the whole shall be removed And this it is That there be restored into the Lake as much Water as can be possible and in particular from the upper parts of Venice taking care that the Water be as free from Mud as is possible And that this is the true and real remedy of the precedent disorders is manifest For in the passage that this Water shall make thorow the Lakes it shall of it self by degrees clear the Chanels in sundry parts of them according to the currents that it shall successively acquire and in this manner being dispersed thorow the Lake it shall maintain the waters in the same and in the Chanels much higher as I shall prove hereafter a thing that will make Navigation commodious and that which moreover is of great moment in our businesse those Shelves of Mud which now discover themselves at the time of Low-Waters shall be alwayes covered so that the putrefaction of the Air shall also be remedied And lastly this abundance of Water being alwayes to discharge it self into the Sea by the Ports I do not doubt but that their bottomes will be scoured And that these effects must follow Nature her self seemeth to perswade there remaining onely one great doubt whether that abundance of Water that shall be brought into the Lake may be really sufficient to make the Waters rise so much as to keep the Shelves covered and to facilitate Navigation which ought to be at least half a Brace or thereabouts And indeed it seemeth at first sight to be impossible that the sole Water of the Brent let into the Lake and dispersed over the same can occasion so notable an height of water and the more to confirm the difficulties one might say reducing the reason to calculation that in case the Brent were 40. Braces broad and two and an half high and the breadth of the Lake were 20000. Braces it would seem necessary that the height of the water of the Brent dilated and distended thorow the Lake would be but onely 1 100 of a Brace in height which is imperceptible and would be of no avail to our purpose nay more it being very certain that the Brent runneth very muddy and foul this would occasion very great mischief filling and contracting the Lake and for that reason this remedy ought as pernicious to be totally excluded and condemned I here confesse that I am surprized at the forme of the Argument as if I were in a certain manner convinced that I dare not adventure to say more or open my mouth in this matter but the strength it self of the Argument as being founded upon the means of Geometrical and Arithmetical Calculation hath opened me the way to discover a very crafty fraud that is couched in the same Argument which fraud I will make out to any one that hath but any insight in Geometry and Arithmetick And as it is impossible that such an argument should be produced by any but such as have tasted of these in such affairs most profitable and most necessary Sciences so do not I pretend to make my self understood save onely by such to whom I will evince so clearly as that more it cannot be desired the errour and fraud wherein those Ancients and Moderns have been and alwayes are intangled that have in any way yet handled this matter of considering the Measure and Quantity of the Waters that move And so great is the esteem that I have for that which I am now about to say touching this particular that I am content that all the rest of my Discourse be rejected provided that that be perfectly understood which I am hereafter to propose I holding and knowing it to be a main Principle upon which all that is founded that can be said either well or handsomely on this particular The other Discourses may have an appearance of being probable but this hits the mark as full as can be desired arriving at the highest degree of certainty I have seventeen years since as I represented to the most Serene Prince and to the Right Honourable the President of the Lords the Commissioners of the Sewers written a Treatise of the Measure of the waters that move in which I Geometrically demonstrate and declare this businesse and they who shall have well understood the ground of my Discourse will rest fully satisfied with that which I am now about to propose But that all may become rhe more easie I will more briefly explicate and declare so much thereof as I have demonstrated in the Discourse which will suffice for our purpose And if that should not be enough we have alwayes the experiment
in equal times but that one of them should be four times more swift than the other the more slow should of necessity be four times more large And because the same River in any part thereof alwaies dischargeth the same quantity of Water in equal times as is demonstrated in the first Proposition of the first Book of the measure of Running Waters but yet doth not run thorowout with the same velocity Hence it is that the vulgar measures of the said River in divers parts of its Chanel are alwaies divers insomuch that if a River passing through its chanel had such velocity that it ran 100 Braces in the 1 1 60 of an hour-and afterwards the said River should be reduced to so much tardity of motion as that in the same time it should not run more than one Brace it would be necessary that that same River should become 100. times bigger in that place where it was retarded I mean 100. times bigger than it was in the place where it was swifter And let it be kept well in mind that this point rightly understood will clear the understanding to discover very many accidents worthy to be known But for this time let it suffice that we have onely declared that which makes for our purpose referring apprehensive and studious Wits to the perusal of my aforenamed Treatise for therein he shall finde profit and delight both together Now applying all to our principal intent I say That by what hath been declared it is manifest that if the Brent were 40. Braces broad and 2 1 2 high in some one part of its Chanel that afterwards the same Water of the Brent falling into the Lake and passing thorow the same to the Sea it should lose so much of its velocity that it should run but one Brace in the time wherein whilst it was in its Chanel at the place aforesaid it ran 100. Braces It would be absolutely necessary that increasing in measure it should become an hundred times thicker and therefore if we should suppose that the Lake were 20000. Braces the Brent that already hath been supposed in its Chanel 100. Braces being brought into the Lake should be 100. times 100. Brates that is shall be 10000. Braces in thickness and consequently shall be in height half a Brace that is 100 200 of a Brace and not 1â—â— 200 of a Brace as was concluded in the Argument Now one may see into what a gross errour of 99. in 100. one may fall through the not well understanding the true quantity of Running Water which being well understood doth open a direct way to our judging aright in this most considerable affair And therefore admitting that wich hath been demonstrated I say that I would if it did concern me greatly encline to consult upon the returning of the Brent again into the Lake For it being most evident that the Brent in the Chanel of its mouth is much swifter than the Brent being brought into the Lake it will certainly follow thereupon that the thickness of the Water of Brent in the Lake shall be so much greater than that of Brent in Brent by how much the Bront in Brent is swifter than thh Brent in the Lake 1. From which operation doth follow in the first place that the Lake being filled and increased by these Waters shall be more Navigable and passible than at present we see it to be 2. By the current of these Waters the Chanels will be scoured and will be kept clean from time to time 3. There will not appear at the times of low-waters so many Shelves and such heaps of Mud as do now appear 4. The Ayr will become more wholesom for that it shall not be so infected by putrid vapours exhaled by the Sun so long as the Miery Ouze shall be covered by the Waters 5. Lastly in the current of these advantagious Waters which must issue out of the Lake into the Sea besides those of the Tyde the Ports will be kept scoured and clear And this is as much as I shall offer for the present touching this weighty buisiness alwaies submitting my self to sounder judgements Of the above-said Writing I presented a Copy at Venice at a full Colledge in which I read it all and it was hearkned to with very great attention and at last I presented it to the Duke and left some Copies thereof with sundry Senators and went my way promising with all intenseness to apply my pains with reiterated studies in the publick service and if any other things should come into my minde I promised to declare them sincerely and so took leave of His serenity and that Noble Council When I was returned to Rome this business night and day continually running in my mind I hapned to think of another admirable and most important conceit which with effectual reasons confirmed by exact operations I with the Divine assistance made clear and manifest and though the thing at first sight seemed to me a most extravagant Paradox yet notwithstanding having satisfied my self of the whole business I sent it in writing to the most Illustrious and most Noble Signore Gio. Basadonna who after he had well considered my Paper carried it to the Council and after that those Lords had for many months maturely considered thereon they in the end resolved to suspend the execution of the diversion which they had before consulted to make of the River Sile and of four other Rivers which also fall into the Lake a thing by me blamed in this second Paper as most prejudicial and harmful The writing spake as followeth CONSIDERATIONS Concerning the LAKE OF VENICE CONSIDERATION II. IF the discoursing well about the truth of things Most Serene Prince were as the carrying of Burdens in which we see that an hundred Horses carry a greater weight than one Horse onely it would seem that one might make more account of the opinion of many men than of one alone But because that discoursing more resembleth running than carrying Burdens in which we see that one Barb alone runneth faster than an hundred heavy-heel'd Jades therefore I have ever more esteemed one Conclusion well managed and well considered by one understanding man although alone than the common and Vulgar opinions especially when they concern abstruce and arduous points Nay in such cases the opinions moulded and framed by the most ignorant and stupid Vulgar have been ever suspected by me as false for that it would be a great wonder if in difficult matters a common capacity should hit upon that which is handsom good and true Hence I have and do hold in very great veneration the summe of the Government of the most Serene and eternal Republick of Venice which although as being in nature a Common-wealth it ought to be governed by the greater part yet nevertheless in arduous affairs it is alwaies directed by the Grave Judgement of few and not judged blindly by the Plebeian Rout. T is true that he that propoundeth
strange and unlikely to many others The point is that I say That by raising the level of Fiume morto one half Brace onely at its Mouth it will penipenitrate into Serchio farther than it would into the Sea it shall cause the waters to rise three or perhaps more Braces upon the fields towards Pisa and still more by degrees as they shall recede farther from the Sea-side and thus there will follow very great Innundations and considerable mischiefs And to know that this is true you are to take notice of an accident which I give warning of in my discourse of the Measure of Running Waters where also I give the reason thereof Coroll 14. The accident is this That there coming a Land-Flood for example into Arno which maketh it to rise above its ordinary Mouth within Pisa or a little above or below the City six or seven Braces this same height becometh alwaies lesser and lesser the more we approach towards the Sea-side insomuch that near to the Sea the said River shall be raised hardly half a Brace Whence it followeth of necessary consequence that should I again be at the Sea-side and knowing nothing of what hapneth should see the River Arno raised by the accession of a Land-flood one third of a Brace I could certainly infer that the same River was raised in Pisa those same six or seven Braces And that which I say of Arno is true of all Rivers that fall into the Sea Which thing being true it is necessary to make great account of every small rising that Fiume morto maketh towards the Sea-side by falling into Serchio For although the rising of Fiume morto by being to disgorge its Waters into Serchio towards the Sea were onely a quarter of a Brace we might very well be sure that farr from the Sea about Pisa and upon those fields the rise shall be much greater and shall become two or three Braces And because the Countrey lyeth low that same â—ise will cause a continual Innundation of the Plains like as it did before I caused the Mouth to be opened into the Sea And therefore I conclude that the Mouth of Fiume morto ought by no means to be opened into Serchio but ought to be continued into the Sea using all diligence to keep it open after the manner aforesaid so soon as ever the Wind shall be laid And if they shall do otherwise I confidently affirm that there will daily follow greater damages not onely in the Plains but also in the wholesomness of the Air as hath been seen in times past And again It ought with all care to be procured that no waters do by any means run or fall from the Trench of Libra into the Plain of Pisa for these Waters being to discharge into Fiume morto they maintain it much higher than is imagined according to that which I have demonstrated in my consideration upon the state of the Lake of Venice I have said but little but I speak to you who understandeth much and I submit all to the most refined judgment of our most Serene Prince Leopold whose hands I beseech you in all humility to kiss in my name and implore the continuance of his Princely favour to me and so desiring your prayers to God for me I take my leave Rome 1. Feb. 1642. Your most affectionate Servant D. BENEDETTO CASTELLI The answer to a Letter written by BARTOLOTTI touching the difficultyes observed The former part of the Letter is omitted and the discourse beginneth at the first Head ANd first I say Whereas I suppose that the level of the Serchio is higher than that of Fiume morto this is most true at such time as the waters of Fiume morto are discharged into the Sea but I did never say that things could never be brought to that pass as that the level of Fiume morto should be higher than Serchio and so I grant that it will follow that the waters of Fiume morto shall go into Serchio and it s very possible that the Drain of Fiume morto into Serchio may be continuate and I farther grant that its possible that the Serchio doth never disgorge thorow Fiume morto towards Pisa Nay I will yet farther grant that it might have happened that Fiume morto might have had such a fall into Serchio as would have sufficed to have turned Mills But then I add withall that the Plains of Pisa and the City it self must be a meer Lake 2. Signore Bartolotti saith confidently that when the Sea swelleth by the South-West or other Winds the level of Serchio in the place marked A in the Platt distant about 200. Braces riseth very little But that Fiume morto in D and in E many miles more up into Land riseth very much and that certain Fishermen confirm this and shew him the signes of the rising of the Water I grant it to be very true and I have seen it with my own eyes But this cometh to pass when the Mouth of Fiume morto is stopt up by the Sea as I shall shew by and by And this rising near the Sea-side is of no considerable prejudice to the fields And this is as much as I find to be true in the assertion of Signore Bartolotti without his confirming it by any other proof as indeed it needs none That the level of Fiume morto riseth in E and many miles farther upwards it riseth much nor did I ever affirm the contrary 3. Concerning the difficulty of opening the Mouth of Fiume morto into the Sea that which Il Castellano saith is most certain namely That at the entrance upon the opening of the Mouth it is necessary to make a deep Trench But I say that at that time it is difficult to open it unless upon great occasions for that the difficulty proceedeth from the waters of Fiume morto being low and the fields drained 4. As to the particular of the Causes that you tell me men press so much unto the most Serene Grand Duke and to the Prince I have not much to say because it is not my profession nor have I considered of the same Yet I believe that when the Prince and his Highnesse see the benefit of his People and Subjects in one scale of the Ballance and the accomodation of Huntsmen in the other his Highnesse will incline to the profit of his subjects such have I alwayes found his Clemency and Noblenesse of minde But if I were to put in my vote upon this businesse I would say that the points of Spears and the mouths of Guns the yelping of Dogs the wilynesse of Huntsmen who run thorow and narrowly search all those Woods Thickets and Heathes are the true destroyers of Bucks and Boares and not a little Salt-water which setleth at last in some low places and spreadeth not very far Yet neverthelesse I will not enter upon any such point but confine my self solely to the businesse before me 5. That Experiment of joyning together the water
distend for to this instance we answer with that which we have given notice of in the First Consideration touching the Lake of Venice treating of the abatement that is caused by the Brent let into the Lake And moreover if I shall adde thereto that which I write in the Second Consideration it will be very apparent how greatly harmfull and prejudicial these excursions of Waters from Fiume Sisto may be which are not kept under and confined within the River Therefore proceeding to the provisions and operations that are to be accounted Principall I reduce them to three Heads In the first place it is necessary to throw down those Weares and to take the Pisciaries quite away observing a Maxime in my judgment infallible that Fishing and Sowing are two things that can never consist together Fishing being on the Water and Sowing on land Secondly it will be necessary to cut under Water in the bottome of the River those Weeds and Plants that grow and increase in the River and leave them to be carried into the Sea by the Stream for by this means these Reeds shall not spring up and distend along the bottome of the River by means of the Beasts treading upon them And the same ought to be done often and with care and must not be delaied till the mischief increase and the Champain Grounds be drowned but one ought to order matters so as that they may not drown And I will affirm that otherwise this principal point would become a most considerable inconvenience Thirdly it is necessary to make good the Banks of Fiume Sisto on the left hand and to procure that those Waters may run in the Chanel and not break forth And it is to be noted that it is not enough to do one or two of those things but we are to put them all in execution for omitting any thing the whole machine will be out of tune and spoiled But proceeding with due care you shall not only Drain the Pontine Fens but by means of this last particular the Current of Fiume Sisto shall scowr its own Chanel of its self even to the carrying part of it away and haply with this abundance of water that it shall bear the Mouth della Torre may be opened and kept open into the Sea And it would last of all be of admirable benefit to cleanse Fiume Sisto from many Trees and Bushes wherewith it is overgrown And with this I conclude that the Improvement or Drain possible to be made consisteth in these three particulars First in taking away the Fishing Weares leaving the Course of the Waters free Secondly in keeping the Principal Rivers clear from Weeds and Plants Thirdly in keeping the water of Fiume Sisto in its own Chanel All which are things that may be done with very little charge and to the manifest benefit of the whole Country and to the rendering the Air wholsomer in all those Places adjoyning to the Pontine Fens A CONSIDERATION Upon the DRAINING Of the Territories of Bologna Ferrara AND Romagna BY D. BENEDETTO CASTELLI Abbot of S. BENEDETTO ALOISIO Mathematician to P. Vrban VIII and Professor in the University of ROME THe weghty businesse of the Draining of the Territories of Bologna Ferrara and Romagna having been punctually handled and declared in writing from the excellent memory of the Right Honourable and Noble Monsignore Corsini who was heretofore Deputed Commissary General and Visitor of those Waters I am not able to make such another Discourse upon the same Subject but will only say somewhat for farther confirmation of that which I have said in this Book upon the Lake of Venice upon the Pontine Fens and upon the Draining of those Plains of Pisa lying between the Rivers Arno and Serchio whereby it is manifest that in all the aforementioned Cases and in the present one that we are in hand with there have in times past very grosse Errours been committed through the not having ever well understood the true measure of Running waters and here it is to be noted that the businesse is that in Venice the diversion of the waters of the Lake by diverting the Brent was debated and in part executed without consideration had how great abatement of water might follow iâ— the Lake if the Brent were diverted as I have shewn in the first Consideration upon this particular from which act there hath insued very bad consequences not only the difficulty of Navigation but it hath infected the wholsomnesse of the Air and caused the stoppage of the Ports of Venice And on the contrary the same inadvertency of not considering what rising of the Water the Reno and other Rivers being opened into the Valleys of Bologna and Ferrara might cause in the said Valleys is the certain cause that so many rich and fertile Fields are drowned under water converting the happy habitations and dwellings of men into miserable receptacles for Fishes Things which doubtlesse would never have happened if those Rivers had been kept at their height and Reno had been turn'd into Main-Po and the other Rivers into that of Argenta and of Volano Now there having sufficient been spoken by the above-named Monsig Corsini in his Relation I will only adde one conceit of my own which after the Rivers should be regulated as hath been said I verily believe would be of extraordinary profit I much doubt indeed that I shall finde it a hard matter to perswade men to be of my mind but yet nevertheless I will not question but that those at least who shall have understood what I have said and demonstrated concerning the manners and proportions according to which the abatements and risings of Running waters proceed that are made by the Diversions and Introductions of VVaters will apprehend that my conjecture is grounded upon Reason And although I descend not to the exactnesse of particulars I will open the way to others who having observed the requisite Rules of considering the quantity of the waters that are introduced or that happen to be diverted shall be able with punctuality to examine the whole businesse and then resolve on that which shall be expedient to be done Reflecting therefore upon the first Proposition that the Risings of a Running Water made by the accession of new water into the River are to one another as the Square-Roots of the quantity of the water that runneth and consequently that the same cometh to pass in the Diversions Insomuch that a River running in height one such a certain measure to make it encrease double in height the water is to be encreased to three times as much as it ran before so that when the water shall be quadruple the height shall be double and if the water were centuple the height would be decuple onely and so from one quantity to another And on the contrary in the Diversions If of the 100. parts of water that run thorow a River there shall be diverted 19 1â—â— the height of the River diminisheth onely 1 10
do not happen in our Mediterranean Sea yet doth not this invalidate the reason and cause that I shall produce if so be that it verifie and fully resolve the accidents which evene in our Sea for that in conclusion there can be but one true and primary cause of the effects that are of the same kind I will relate unto you therefore the effects that I know to be true and assigne the causes thereof that I think to be true and you also Gentlemen shall produce such others as are known to you besides mine and then we will try whether the cause by me alledged may satisfie them also I therefore affirm the periods that are observed in the fluxes and refluxes of the Sea-waters to be three the first and principal is this great and most obvious one namely the diurnal according to which the intervals of some hours with the waters flow and ebbe and these intervals are for the most part in the Mediterrane from six hours to six hours or thereabouts that is they for six hours flow and for six hours ebbe The second period is monethly and it seemes to take its origen from the motion of the Moon not that it introduceth other motions but only altereth the greatnesse of those before mentioned with a notable difference according as it shall wax or wane or come to the Quadrature with the Sun The third Period is annual and is seen to depend on the Sunne and onely altereth the diurnal motions by making them different in the times of the Solstices as to greatnesse from what they are in the Equinoxes We will speak in the first place of the diurnal motion as being the principal and upon which the Moon and Sun seem to exercise their power secondarily in their monethly and annual alterations Three differences are observable in these horary mutations for in some places the waters rise and fall without making any progressive motion in others without rising or falling they run one while towards the East and recur another while towards the West and in others they vary the heights and course also as happeneth here in Venice where the Tides in coming in rise and in going out fall and this they do in the extermities of the lengths of Gulphs that distend from West to East and terminate in open shores up along which shores the Tide at time of flood hath room to extend it self but if the course of the Tide were intercepted by Cliffes and Banks of great height and steepnesse there it will flow and ebbe without any progressive motion Again it runs to and again without changing height in the middle parts of the Mediterrane as notably happeneth in the Faro de Messina between Scylla and Carybdis where the Currents by reason of the narrownesse of the Channel are very swift but in the more open Seas and about the Isles that stand farther into the Mediterranean Sea as the Baleares Corsica Sardignia Elba Sicily towards the Affrican Coasts Malta Candia c. the changes of watermark are very small but the currents indeed are very notable and especially when the Sea is pent between Islands or between them and the Continent Now these onely true and certain effects were there no more to be observed do in my judgment very probably perswade any man that will contain himself within the bounds of natural causes to grant the mobility of the Earth for to make the vessel as it may be called of the Mediterrane stand still and to make the water contained therein to do as it doth exceeds my imagination and perhaps every mans else who will but pierce beyond the rinde in these kind of inquiries SIMP These accidents Salviatus begin not now they are most ancient and have been observed by very many and several have attempted to assigne some one some another cause for the same and there dwelleth not many miles from hence a famous Peripatetick that alledgeth a cause for the same newly fished out of a certain Text of Aristotle not well understood by his Expositors from which Text he collecteth that the true cause of these motions doth only proceed from the different profundities of Seas 〈…〉 waters of greatest depth being greater in abundance and therefore more grave drive back the Waters of lesse depth which being afterwards raised desire to descend and from this continual colluctation or contest proceeds the ebbing and flowing Again those that referre the same to the Moon are many saying that she hath particular Domination over the Water and at last a certain Prelate hath published a little Treatise wherâ—in he saith that the Moon wandering too and fro in the Heavens attracteth and draweth towards it a Masse of Water which goeth continually following it so that it is full Sea alwayes in that part which lyeth under the Moon and because that though she be under the Horizon yet neverthelesse the Tide returneth he saith that no more can be said for the salving of that particular save onely that the Moon doth not onely naturally retain this faculty in her self but in this case hath power to confer it upon that degree of the Zodiack that is opposite unto it Others as I believe you know do say that the Moon is able with her temperate heat to rarefie the Water which being rarefied doth thereupon flow Nor hath there been wanting some that SAGR. I pray you Simplicius let us hear no more of them for I do not think it is worth the while to wast time in relating them or to spend our breath in confuting them and for your part if you gave your assent to any of these or the like fooleâ—ies you did a great injury to your judgment which neverthelesse I acknowledg to be very piercing SALV But I that am a little more flegmatick than you Sagredus will spend a few words in favour of Simplicius if haply he thinks that any probability is to be found in those things that he hath related I say therefore The Waters Simplicius that have their exteriour superficies higher repel those that are inferiour to them and lower but so do not those Waters that are of greatest profundity and the higher having once driven back the lower they in a short time grow quiet and level This your Peripatetick must needs be of an opinion that all the Lakes in the World that are in a calme and that all the Seas where the ebbing and flowing is insensible are level in their bottoms but I was so simple that I perswaded my self that had we no other plummet to sound with the Isles that advance so high above Water had been a sufficient evidence of the unevennesse of their bottomes To that Prelate I could say that the Moon runneth every day along the whole Mediterrane and yet its Waters do not rise thereupon save onely in the very extream bounds of it Eastward and here to us at Venice And for those that make the Moons