An Account of Several Books
Author(s)
Johannis Hevelii, Isaacus Vossius, M. de Cordemoy
Year
1665
Volume
1
Pages
11 pages
Language
en
Journal
Philosophical Transactions (1665-1678)
Full Text (OCR)
Thermometers, Barometers, Hygrometers.
These Observations being thought very considerable as well as curious, 'tis hoped, that those who have conveniency, will give encouragement and assistance for the making of them; and withall oblige the publick by imparting, what they shall have observed of this kind: The Publisher intending, that whenever such observations shall be communicated to him, he will give notice of it to the publick, and take care of the improvement thereof to the best use and advantage. A Pattern of the Table, proposed to be made for observing the Tides, is intended to be published the next opportunity, God permitting.
An Account
Of several Books lately published.
I. Johannis Hevelii DESCRIPTIO COMETÆ, Anno Æra Christianæ MDCLXV. exorti; una cum MANTISSA Prodromi Cometici, Observationes omnes prioris COMETÆ MDCLIV, ex illoque genuinum motum accuratè deductum, cum Notis & Animadversionibus, exhibens.
This Book (as the Title itself intimates) undertakes two things. First, To give an Account of the Second of the two late Comets, which appeared, when the other was scarce extinct; Concerning which, the Author doth, from the Observations made by himself with a Sextant of 6 foot, and divided into minutes and seconds, assign both its true place (as well in respect of the Ecliptick as the Equator) and its proper motion: Adding a fair Delineation of its Course, together with the genuine Representations of its Head and Train, in each day of its apparition; and subjoynig a General Description and Discourse of some of the more notable Phænomena thereof. It was first seen at Danzig by the Watchmen, the 5th of April st. n. 1665, and then observed by the Author, from April 6. about 3½ of the Clock in the morning, till April 20. at 3. in the morning. During which time, it went with a reasonable velocity; making 46 deg. in its Orb, according to the Order of the Signs, moving from the Breast of Pegasus, towards the Head of Andromeda, and the Left Horn of Aries; having, as 'tis presumed, taken its rise from above Sagitta, and run through the Breast of Antinous, under Aquila, and the Dolphin, to the said Pegasus; and so on, as is already expressed.
The Head of it is in the Book described of a Colour like that of Jupiter, all along much brighter than that of the former Comet, though of a somewhat less magnitude; having in its middle onely one round, but very bright and big Kernel or Speck, resplendent like Gold, and encompassed with another more dilute and seemingly uniform matter: its Tail being at first, about 17 deg. and afterwards 20, and sometimes 25 deg. long, and divaricated towards the End.
Next, it is observed, that though this Star did afterwards slacken its pace, yet it retained the vividness of its Colour, both of the Head and Train; the Head especially, keeping at the time as well of the last observations, as of the first
first, the brightness of its single kernel, though the environing more dilute matter were then almost all lost; it being, according to the Author, more and more attenuated, and grown narrow, the nearer the Star approached to the Sun.
Thirdly, 'tis noted, That this Comet did very much digress from the Hypothesis, delivered by M. Auxout, in regard that, whereas according to that Hypothesis, this Star should not arrive to the Ecliptick till after the space of 3 months; it arrived there the 28 of April. And then, that its first Conjunction with the Sun happened between the 19 and 20 of April, and the second, the last of April, not (as M. Auxout would have it) the 15 of May. So that he concludes, that this Comet never came down to the Pleiads and the Eye of Taurus, as the Hypothesis of M. Auxout requires, but that from April 20, it did immediately take its course towards the Ecliptick, deflecting every day more and more from the Section of a Great Circle, to the Lucida of Aries, arriving at the Ecliptick the last of April, about the 8th or 10th deg. of Taurus; not in July about the 8th of Gemini, and the Eye of Taurus.
Fourthly, He intimates, that if this Comet had appeared some few weeks sooner, it would have confronted the former Comet, being yet in its vigour and of a conspicuous bigness, in the same place, where that was, viz. the Head of Aries.
Fifthly, He observes, that this Star in progress of time became Retrograde, whence it came to pass, that in the Months of June and July it did not appear again before the Rising of the Sun, though the Sun left it far behind: whereas, if it had proceeded toward the Eye of Taurus, it would have appeared again in the morning.
Sixthly, He maintains, that this Comet was not the same with the former; which he thinks may be demonstrated, only by a due Delineation of both their Course upon the Globe; where he faith it to be evident, that the former could never come to the Head of Pegasus, as moving already in February in a straight Course about the Head of Aries: Besides, that the former went in the very beginning in a Retrograde motion; but this perpetually in a direct one: that, about the end, very slow, its Head lessening and growing dark; this swift enough, with its head conspicuous and bright. To which he adds, that the whole Course of the former was made under a quite different Angle of the Orbite and Ecliptick, and a different Motion of the Nodes from the latter: As also that their Faces differed very much from one another; the first exhibiting all along a matter, which as to its density and rarity, altered from day to day exceedingly, whereas the second retained (to the Authors admiration, who affirms, never to have observed the like) all the time he saw it, one and the same round, dense and bright Speck or Kernel.
All which he concludes 1, With an Intimation of his sense concerning two other Comets, pretended to have been lately seen, One at Rome, about the Girdle
Girdle of Andromeda, in the Months of February and March, 1664; the other in Germany in Capricorne, about Saturne in the head of Sagittary, during the Months of September and October, 1665.
With an Advertisement of what he has done in that important Work for the Advancement of Astronomy, the due Restitution of the Fixt Stars, vid. That he has almost finish't it, himself alone, without trusting to any other man's labour, that was not directed by him.
The Second Part of this Book (the Mantissa to the Prodromus Cometicus) endeavours to justify the Author's Observations touching the former Comet, excepted against by M. Auzout, in several particulars, as 1. That it had not pass'd to the First, but Second Star in Aries, and had mov'd in quite another Line, than He had described. 2. That its proper motion about the end of January and the beginning of February, 1665, had not been rightly assigned. 3. That the Bignesse of its Diameter had not been truly delivered; Nor 4. The Faces of its Head in due manner represented.
To all which the Author endeavors to answer: 1. By delivering all his Observations of that Comet, thereby to shew, what care and diligence he had used, particularly to make out, how great its Diurnal motion had been; in what proportion, and how far, it decreased, and where and in what degree it increased again: Which being, as he conceives, duly and exactly deduced, and demonstrated, he esteems it afterwards to be easie for every one, versed in these matters, certainly to collect and to judge, what way the Comet, after it became invisible to the naked Eye, and could be no longer observed with Sextants and Quadrants, had taken, and what Line it had described. 2. By subjecting all those Observations, with great diligence and labour, to a rigid Calculus, thereby to obtain, for every day, the Longitudes, Latitudes, Right Ascensions, Declinations, Proper motion, Angle of the Ecliptick and the Equator, and the Nodes of that Comet; for the construction of an Ephemerides of its whole Motion. From all which he pretends to prove, that he has not erred in his Observation of February 18, nor been prepossess'd by any Hypothesis, nor deluded by any Fixt Star, as M. Auzout thinketh; but that near the First Star of Aries there then appear'd a Phenomenon, most like to that Comet, that was seen some days before, if compared with the Observations made thereof Febr. 12, 13, 14. Though he will not hitherto positively determine, whether that Phenomenon, which appear'd to him February 18, was indeed
indeed that very Comet; which he saw with his naked Eye, and observed with his Geometrical Instruments, the said 12, 13, and 14. dayes of February; or whether it was another, and whether he had lost that Comet, which moved towards the Second Star in Aries: but leaves it to the Learned World, and particularly to the Royal Society, after they shall have well examined and considered all his Observations, and the Calculus raised therefrom, to judge of this, and the other particulars in controversie.
II. Isaacius Vossius de NILI et ALIORUM FLUVIUM ORIGINE. It was Numb. 14. of these Transactions, that gave an account of the Cause of the Inundation of the Nile, as it was rendered by Monsieur de la Chambre: This is to give you another, not only of the Inundation, but also of the Origine of that, and of other Rivers, as it is delivered by Monsieur Isaac Vossius, who undertakes in this Book to shew;
1. That those Subterraneous Channels, through which several Philosophers teach, that the Sea discharges itself into the Rivers, are not only imaginary, but useless, in regard 'tis impossible for the water to rise from the Subterraneous places up to the Mountains, where commonly the Sources of Rivers are.
2. He explicates, why, if a Pipe be put into a Bason full of Water, the water is seen more raised in the Pipe, than in the Bason, and rises higher according as the Pipe is narrower; On the contrary, if the same Pipe be put into a Bason full of Quicksilver, the Quicksilver stays lower in the Pipe, than in the Bason. The reason, which he renders hereof, is, That as the Water sticks easily to all it touches, it is sustain'd by the sides of the narrow Pipe wherein it is included: And indeed, if the pipe be quite drawn out of the Water, the Water doth not all fall out, but so much of it remains, as the sides of the Pipe could sustain: Whence it is, that the Water which is kept up by the Walls of the Tube, weighing no longer upon that which is in the Bason, is thrust upwards, and keeps itself raised above its Levell; but the Quicksilver not adhering so easily, as Water, to Bodies it touches, is not sustained by the sides of the Tube, and so mounts not above its Levell, but rather descends below it, because the pipe, which is straight, hinders the endeavor that is in the Mercury to rise to its Level. He adds, that this Observation makes nothing for the Explication of the Origine of Rivers; because, though it be true, that the Water
by this means rises above its Level, yet it does never run off at the top of the Pipe. Having said this, he answers to the other Arguments, commonly alleged to maintain this Opinion.
3. He pretends, that all Rivers proceed from a Colluvies or Rendevous of Rain-waters, and that, as the Water, that falls upon Hills, gathers more easily together, than that which falls in Plains, therefore it is, that Rivers ordinarily take their Source from Hills. Thence also comes it (saies he) that there are more Rivers, than Torrents, in the Temperate Zones; and, on the contrary, more Torrents, than Rivers, in the Torrid Zone: For, as in hot Climates the Mountains are far higher, the Water, that descends from them with impetuosity, runs away in a little while, and formes such Collections of Water, as soon dry up; but in cold Climates, the Waters do not run away but slowly, and are renew'd and recruited by Rain, before they are quite dried up; because the Hills are there lower, and so the Bed of Rivers hath lesse declivity.
Having thus discoursed of Rivers in General, he treats of the Nile in particular; and there
1. Observes, That the Order of the Seasons of the Year is quite inverted under the Torrid Zone. For, whereas it should be then Summer, when the Sun is near; and Winter, when the Sun is farther off: Under the Torrid Zone 'tis never lesse hot, than when the Sun is nearest; nor more hot, than when the Sun is farther off: So that to the people that live between the Equinoctial and the Tropicks, Summer begins about Christmas, and their Winter, about St. John's day. The reason whereof is, (saith he) that when the Sun is directly over their Heads, it raises abundance of vapors, and draws them so high, that they are presently converted into Water by the coldnesse of the Air; whence it comes to passe, that then it rains continually, which does refresh the Air; but when the Sun is farther off, there falls no more rain, and so the Heat becomes insupportable.
2. He proves by many recent Relations, that the Sources of the Nile are on this side of the Equinoctial in Ethiopia; of which he gives a very accurate Mappe, correcting many faults which Geographers are wont to commit in the Description of the Kingdom of the Abyssins, which they believe to be much greater than indeed it is.
3. This supposed, he easily gives an account, why the Nile yearly overflows about the end of June: For, as at that time there falls much rain in Ethiopia, it must needs be, that the Nile, whose source is in that Country, should then overflow, when those rains begin, and subside, when they cease.
There are besides, in this Book, two other Tracts. In the first, M. Voisin endeavours to maintain the Doctrine, he had deliver'd in his Book De Lumine, and to shew, that the Soul of Animals is nothing but Fire, that there are no invisible Atoms; nor so much as any Pores, even in the Skin of man. Here he treats also of Refractions, and alleges the Examples of several persons, who have then seen the Sun by the means of Refraction, when really He was under the Horizon.
In the second, He discourses of some points of the Mechanicks; and relates among other things, that the Arrows and battering Rams (Arises) of the Antients did as much execution, as our Muskets and Canons; and then, that the Vehemence of the percussion depends as much upon the Length of the percipient Body, as upon the velocity of the Motion. He adds, that the Length of a Canon ought not to exceed 13 foot, and that a greater length is not only useless, but hinders also the effect of the Gun, not because the Bullet is thrown out of the Gun, before all the powder is fired (as some believe;) but because the Bullet is then beaten back into the Gun by the Air, re-entering into it with impetuosity, when the flame is extinct.
III. LE DISCERNEMENT DU CORPS ET DE L'AME, par M. de Cordemoy.
This French Treatise (but very lately come to the Publisher's hands) examines the different Operations of the Soul and Body, and the Secret of their Union; pretending to discover to every one, what he is, and what is transacting within him. It consists of six Discourses.
1. In the first, the Author examines the Notions, we have in general of Bodies and Matter; of Quantity; of Qualities; of Place; of Rest; of Motion; of Vacuity; of Forms: to shew what is to be understood by these Terms, which cause all the perplexity that is in the ordinary Physicks. He begins with taking notice, that hitherto Philosophers have had no distinct notions of Bodies and Matter; from the want whereof he conceives, that almost all the Errors in Common Physiology have sprung.
sprung! To rectify which, he defines Bodies to be * Extended Substances, and Matter an Aggregate of Bodies. Whence he infers, that Bodies are Indivisible and Matter divisible; a Body being nothing but one and the same Substance, whose different extremities are inseparable, because they are the extremities of one and the same Extension, and, in a word, of one and the same Substance: but Matter being nothing but an Association or Collection of Bodies, 'tis evident, (faith he) it must be divisible. This doctrine he so much insists upon, that he conceives, Nature cannot subsist, if a Body in the sense he takes it, be divisible; and that Motion and Rest cannot be explicated without it. As for Quantity, he makes that to be nothing but More or Less Bodies; not allowing, that each Body should be a Quantity, though it be a part of Quantity; no more than an Unit is a Number, though it make part of a Number: so that Quantity and Extension are two distinct things with him, the first belonging properly to Matter, the last to a Body. Touching Vacuity, he conceives, that the Bodies, which compose a mass, are not everywhere so near one another, as not to leave some interval in several places. Neither does he think it necessary, that those intervals should be fill'd up; nor unconceivable, that there should be no Body between two Bodies, which touch not one another. And when 'tis said, that those intervals cannot be conceived without Extension, and that consequently there are Bodies that replenish them, he frankly pronounces that not to be true; and affirms, that though it may be said, that between two Bodies, which touch not one another, other Bodies may be placed of so or so many feet, &c. yet ought it not to be inferred, that therefore they are there, but onely, that they are thus placed, that there may be put between them so many Bodies, as joyned together would compose an Extension of so many feet. So that one conceives onely, that Bodies may be placed there, but not that they are there: and as we can have an Idea of many Bodies, though none of them be in being; so we can conceive, that some Bodies may be put between others, where really there are none. And when 'tis alleged; that if all the Bodies, that fill a vessel full, were destroyed, the sides of the vessel would be closed together; He professes, he understands not that ratiocination, nor can conceive, what one Body does to the subsistence of another, more than to sustain themselves mutually, when they are thrust by the neighbouring ones: and therefore sees not, why the sides of the vessel should close, if nothing did thrust them together; but understands clearly, that two Bodies may well subsist so far from one another, that one might place a great many Bodies between them, or none at all, and yet they neither approach to, nor recoil from one another.
2. In the Second, he examines the Changes, which he knows in Matter, and makes it his business to explicate all those that respect Quantity, Qualities and Forms, by Local Motion, esteeming their needs no other.
3. In the third, he explains the Motion of Artificial Beings, and that of Natural ones, by one and the same Cause; endeavouring among other things to shew, that the Body of an Animal is moved after the same manner with a Watch. That cause of motion he makes the Materia Subtilis; and the finer or subtler that is, the better and fitter he conceives it to be to preserve Motion.
4. In the Fourth, he teaches, that though Experience seems to evince, that the Soul moves the Body, and that one Body moves another; yet there is nothing, but God, that can produce any motion in the World, and all other Agents, which we believe to be the Cause of this or that Motion, are no more but the Occasion thereof. In doing this, he advances certain Axioms, and Conclusions, which are in short,
a. The Axioms: That no substance has that of itself, which it can loose, without ceasing to be, what it is: That every body may loose of its motion, till it have no more left, without ceasing to be a Body: That we cannot conceive but two sorts of substances, vid. a Spirit (or That which thinketh) and a Body, wherefore they must be considered as the Causes of all, that happens, and what cannot proceed from the one, must necessarily be ascribed to the other: That to Move, or to cause motion, is an Action: That an Action cannot be continued but by the Agent, who began it.
b. The Conclusions: That no Body hath Motion of itself: That the First Mover of Bodies is not a Body: That it cannot be but a Spirit, that is the First Mover: That it cannot be but the same Spirit, who has begun to move Bodies, that continues to move.
In the Fifth, He treats of the Union of the Body and Soul, and the manner, how they act one upon the other; and esteem it not more difficult to conceive the Action of Spirits upon Bodies, and of Bodies upon Spirits, than to conceive the Action of Bodies upon Bodies: the cause of the great difficulty in understanding the two former; arising (according to him) from thence, that we will conceive the one by the other, not considering, that every thing acting according to its own nature, we shall never know the action of one Agent, if we will examine it by the notions we have of another, that is of a quite differing nature. Here he notes, that the Action of Bodies upon Bodies is not more
more known to us, than that of Spirits upon Bodies, or of Bodies upon Spirits; and yet most men admire nothing but this, believing to know the other: whereas he Judges, that all things being well examin'd, the Action of Bodies upon Bodies is no more conceivable, than that of Spirits upon Bodies. Mean while the opinion of the Authour touching this subject, is, That the union of Soul and Body consists only in this, that certain motions of the Body are followed by certain Cogitations of the Soul, and, on the contrary, that certain Thoughts of the Soul are follow'd by certain Motions of the Body. And, having supposed, that Bodies are said to act upon one another, when they cause some change suitable to Extension; and Spirits to act upon one another, when they cause some change suitable to a Thought; he infers, that when a Body acts upon a Spirit, that cannot be by causing any change of motion, of figure, or parts, as having none of all these; nor when a Spirit acts upon a Body, that cannot be by producing any change of Thought, as having none: But, when this Body, or its motion, or figure, or other thing, depending upon its nature, can be perceived by a Spirit, so as, upon that occasion, this Spirit has thoughts, it had not before, it may be said, that the Body has acted upon this Spirit, for as much as it has caused all the change in it, whereof it was capable according to its nature.
In the Sixth, After he hath shew'd, what is to be understood by what we call Soul, and by what we call Body, he labours to make it out, that we are much more assured of the Existence of the Soul, than of that of the Body, which he conceives he can prove from hence, that we cannot doubt, that we think, because even doubting is thinking; but one may doubt, whether one has a body, for several reasons, which he alledges, and thinks so cogent, that he concludes, it is not evident to him by the light of reason, that he has a Body. But supposing, there be Bodies, he examines, what are the Operations, that belong to the Soul, and what those, that belong to the Body; and lastly, what those, that result from the Union of both: And then explains, how all those operations are perform'd, and particularly, Sensation; where he shews, that the Nerves, holding at one end to the Brain, whereof they are but Allongations, and being at the other end extended to the extremities of the Body; when an Object comes to touch those exterior ends of the Nerves, the interior ones in the Brain are presently shaken, and cause different sensations according to the diversitie of Nerves, and the differing manner, in which they are shaken. And to shew, that 'tis this shaking, that causes Sensation, he notes, that if any thing shakes the interior parts of the Nerves, though the object be absent, the Soul has presently the same sensations.
sations, as it would have, if it were present. As, if one should knock on's head forcibly against a wall, the shaking, which the blow gives to the Brain, moving the interior extremities of the Nerve, which causes the sensation of Light, the Soul has the same sensation, which it would have, if it saw a thousand Candles: On the contrary, if the interior extremities of the nerves are not shaken, though the object be present, it causes no sensation; whence it comes, that if a strong Ligature be made upon the middle of the Arm, and the hand be then pricked, no pain is felt, because the shaking of the nerves that are pricked, being stopped by the Ligature, cannot reach to the extremities of the Nerves, that are within the Brain.
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Page 169. lin 27. read, motion of B. above the Center; G. is also, with a Semi-colon after the word Center. p. 274. l. 13, r. it to do to the. p. 277. l. 24. r. natural days. p. 281. l. 16. r. of his. ib. l. 27. r. a notion. p. 293. l. 4. r. enough without. ib. l. 43. r. to the Sine of. p. 294. l. 1. r. to the Sine of.
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