Chapter III: Book I (2)

The Doctor attributes all this to Cold; but I scarce think there could be Cold enough to do all this at _Paris_, and in a Cellar too. Bur his following Stories are not improbable, of Men and Cattle killed with Cold, that remained in the very same Posture in which they died; of which he gives, from a _Spanish_ Captain, this Instance, that happened two Years before, of a Soldier who unfortunately straggled from his Company that were foraging, and was killed with the Cold, but was thought to have fallen into the Enemies Hands. But soon after their return to their Quarters, they saw their Comrade returning, sitting on Horseback, and coming to congratulate him, found him dead, and that he had been brought thither in the same Posture on Horseback, notwithstanding the jolting of the Horse. _Ibid. p._ 18.

[b] Of this Opinion was my late most ingenious and learned Friend, Mr. _Ray_, whose Reasons see in his _Physico-Theolog. Discourses_, Disc. 2. ch. 2. p. 89, _&c_. So also my no less learned and ingenious Friends, Dr. _Halley_, and the late Dr. _Hook_, many of the _French_ Vertuoso’s also, and divers other very considerable Men before them, too many to be specified here.

[c] _An Polycletum quidem admirabimur propter partium Statuæ—convenientiam ac proportionem? Naturam autem non modò non laudabimus, sed omni etiam arte privabimus, quæ partium proportionem non solùm extrinsecus more Statuariorum, sed in profundo etiam servavit? Nonne & Polycletus ipse Naturæ est imitator, in quibus saltem eam potuit imitari? Potuit autem in solis externis partibus in quibus artem consideravit._ With much more to the like Purpose, _Galen. de Us. Part. l. 17. c. 1._

CHAP. IV.

_Of Light._

Thus much for the first Thing ministring to the Terraqueous Globe, the Atmosphere and its Meteors; the next Appendage is _Light_.[a] Concerning which I have in my Survey of the Heavens[b] shewed what admirable Contrivances the infinitely wise Creator hath for the affording this noble, glorious and comfortable Benefit to other Globes, as well as ours; the Provision he hath made by Moons, as well as by the Sun, for the Communication of it.

And now let us briefly consider the great Necessity and Use thereof to all our Animal World. And this we shall find to be little less than the very Life and Pleasure of all those Creatures. For what Benefit would Life be of, what Pleasure, what Comfort would it be for us to live in perpetual Darkness? How could we provide ourselves with Food and Necessaries? How could we go about the least Business, correspond with one another, or be of any Use in the World, or any Creatures be the same to us, without Light, and those admirable Organs of the Body, which the great _Creator_ hath adapted to the Perception of that great Benefit?

But now by the help of this admirable, this first-made[c], because most necessary, Creature of God, by this, I say, all the Animal World is enabled to go here and there, as their Occasions call; they can transact their Business by Day, and refresh and recruit themselves by Night, with Rest and Sleep. They can with Admiration and Pleasure, behold the glorious Works of God; they can view the Glories of the Heavens, and see the Beauties of the flowry Fields, the gay Attire of the feathered Tribe, the exquisite Garniture of many Quadrupeds, Insects, and other Creatures; they can take in the delightsome Landskips of divers Countries and Places; they can with Admiration see the great Creator’s wonderful Art and Contrivance in the Parts of Animals and Vegetables: And in a word, behold the Harmony of this lower World, and of the Globes above, and survey God’s exquisite Workmanship in every Creature.

To all which I might add the Improvements which the Sagacity of Men hath made of this noble Creature of God, by the Refractions and Reflections of Glasses. But it would be endless to enumerate all its particular Uses and Benefits to our World.

But before I leave this Point, there are two Things concerning Light, which will deserve an especial Remark; and that is, its swift and almost instantaneous Motion, and its vast Extension.

1. It is a very great Act of the Providence of God, that so great a Benefit as Light is, is not long in its Passage from Place to Place. For was the Motion thereof no swifter than the Motion of the swiftest Bodies on Earth, such as of a Bullet out of a great Gun, or even of a Sound[d] (which is the swiftest Motion we have next Light), in this Case Light would take up, in its Progress from the Sun to us above thirty two Years at the rate of the first, and above seventeen Years at the rate of the latter Motion.

The Inconveniencies of which would be, its Energy and Vigour would be greatly cooled and abated; its Rays would be less penetrant; and Darkness would with greater Difficulty and much Sluggishness, be dissipated, especially by the fainter Lights of our sublunary, luminous Bodies. But passing with such prodigious Velocity, with nearly the instantaneous Swiftness of almost Two hundred thousand _English_ Miles in one Second of Time,[e] or (which is the same Thing) being but about seven or eight Minutes of an Hour in coming from the Sun to us, therefore with all Security and Speed, we receive the kindly Effects and Influences of that noble and useful Creature of God.

2. Another Thing of great Consideration about Light is, its vast Expansion, it’s almost incomprehensible, and inconceivable Extension, which as a late ingenious Author[f] saith, “Is as boundless and unlimited as the Universe it self, or the Expansum of all material Beings: The vastness of which is so great, that it exceeds the Comprehensions of Man’s Understanding. Insomuch that very many have asserted it absolutely infinite, and without any Limits or Bounds.”

And that this noble Creature of God is of this Extent,[g] is manifest from our seeing some of the farthest distant Objects, the heavenly Bodies, some with our naked Eye, some with the help of Optical Instruments, and others in all Probability farther and farther, with better and better Instruments: And had we Instruments of Power equivalent to the Extent of Light, the luminous Bodies of the utmost Parts of the Universe, would for the same Reason be visible too.

Now as Light is of greatest Use to impower us to see Objects at all, so the Extension thereof is no less useful to enable us to see Objects afar off. By which means we are afforded a Ken of those many glorious Works of the infinite Creator, visible in the Heavens, and can improve them to some of the noblest Sciences, and most excellent Uses of our own Globe.

FOOTNOTES:

[a] It is not worth while to enumerate the Opinions of the _Aristotelians_, _Cartesians_, and others, about the Nature of Light, _Aristotle_ making it a Quality; _Cartes_ a Pulsion, or Motion of the Globules of the second Element, _Vid._ _Cartes Princip._ p. 3. §. 55, _&c._ But with the Moderns, I take _Light_ to consist of material Particles, propagated from the Sun, and other luminous Bodies, not instantaneously, but in time, according to the Notes following in this Chapter. But not to insist upon other Arguments for the Proof of it, our noble Founder hath proved the Materiality of Light and Heat, from actual Experiments on Silver, Copper, Tin, Lead, Spelter, Iron, Tutenage, and other Bodies, exposed (both naked and closely shut up) to the Fire: All which were constantly found to receive an Increment of Weight. I wish he could have met with a favourable Season to have tried his Experiments with the Sun-beams as he intended. _Vid._ _Boyl Exp. to make Fire and Flame ponderable_.

[b] Astro-Theol. Book 7.

[c] Gen. i. 3. _And God said, Let there be Light, and there was Light._

[d] It may not be ungrateful to the Curious, to take notice of the Velocity of these two Things.

According to the Observations of _Mersennus_, a Bullet-shot out of a great Gun, flies 92 Fathom in a Second of Time, (_Vid._ _Mersen. Balist._) which is equal to 589½ Feet _English_, and according to the Computation of Mr. _Huygens_, it would be 25 years in passing from the Earth to the Sun. But according to my own Observations made with one of her Majesty’s _Sakers_, and a very accurate Pendulum-Chronometer, a Bullet, at its first Discharge, flies 510 Yards in five half Seconds, which is a Mile in a little above 17 half Seconds. And allowing the Sun’s Distance to be, as in the next Note, a Bullet would be 32½ Years in flying with its utmost Velocity to the Sun.

As to the Velocity of Sound, see _Book 4. Chap. 3. Note 28._ according to which rate there mentioned, a Sound would be near 17½ Years in flying as far as the distance is from the Earth to the Sun. Confer here the Experiments of the _Acad. del Ciment._ p. 140, _&c._

[e] Mr. _Romer_’s ingenious Hypothesis about the Velocity of Light, hath been established by the _Royal Academy_, and in the _Observatory_ for eight Years, as our _Phil. Trans._ Nᵒ. 136. observe from the _Journ. des Scavans_; our most eminent Astronomers also in _England_ admit it: But Dr. _Hook_ thinks with Monsieur _Cartes_, the Motion of Light Instantaneous, _Hook Post. Works, pag. 77._ And this he endeavours to explain, _pag. 130_, &c.

What Mr. _Romer_’s Hypothesis is, may be seen in the _Phil. Transact._ before-cited: As also in the before commended Sir _Isaac Newton_’s _Opticks_: _Light is propagated from luminous Bodies in time, and spends about seven or eight Minutes of an Hour in passing from the Sun to the Earth. This was first observed by ~Romer~, and then by others, by means of the Eclipses of the Satellites of ~Jupiter~. For these Eclipses, when the Earth is between the Sun and ~Jupiter~, happen about seven or eight Minutes sooner than they ought to do by the Tables; and when the Earth is beyond the ☉, they happen about seven or eight Minutes later than they ought to do: The reason being, that the Light of the Satellites hath farther to go in the latter Case than in the former, by the Diameter of the Earth’s Orbit._ Newt. Opt. L. 2. Part. 3. Prop. 11.

Now forasmuch as the Distance between the Sun and the Earth (according to the Computations in my _Astro-Theology_, _B. 1. ch. 3. Note 2._) is 86051398 _English_ Miles; therefore, at the rate of 7½ Minutes, or 450 Seconds in passing from the Sun, Light will be found to fly above 191225 Miles in one Second of Time.

[f] Dr. _Hook_ Post. Works. Lect. of Light, _pag. 76._

[g] For the proof of this vast Extent of Light, I shall take the Computation of the same great Man, _pag. 77_. _If_, saith he, _we consider first the vast Distance between us and the Sun, which from the best and latest Observations in Astronomy, is judged to be about 10000 Diameters of the Earth, each of which It about 7925 ~English~ Miles; therefore the Sun’s distance is 7925000 Miles; and if we consider that according to the Observations, which I published to prove the Motion of the Earth, ~[which were Observations of the Parallax of some of the fixt Stars in the Head of _Draco_, made in 1699]~ the whole Diameter of the Orb, ~viz.~ 20000, made the Subtense but of one Minute to one of the fixt Stars, which cannot therefore be less distant than 3438 Diameters of this great Orb, and consequently 68760000 Diameters of the Earth: And if this Star be one of the nearest, and that the Stars that are of one Degree lesser in Magnitude (I mean not of the Second Magnitude, because there may be many Degrees between the first and second) be as much farther; and another sort yet smaller be three times as far; and a fourth four times as far, and so onward, possibly to some 100 Degrees of Magnitude, such as may be discovered by longer and longer Telescopes, that they may be 100 times as far; then certainly this material Expansion, a part of which we are, must be so great, that ’twill infinitely exceed our shallow Conception to imagine. Now, by what I last mentioned, it is evident that Light extends it self to the utmost imaginable Parts, and by the help of Telescopes we collect the Rays, and make them sensible to the Eye, which are emitted from some of the almost inconceivably remote Objects, ~&c.~——Nor is it only the great Body of the Sun, or the vast Bodies of the fixt Stars, that are thus able to disperse their Light through the vast Expansum of the Universe; but the smallest Spark of a lucid Body will do the very same Thing, even the smallest Globule struck from a Steel by a Flint, ~&c.~_

CHAP. V.

_Of Gravity._

The last Thing subservient to our Globe, that I shall take notice of, is _Gravity_[a], or that Tendency which Bodies have to the Centre of the Earth.

In my _Astro-Theology_, _Book 6. Ch. 2._ I have shewn of what absolute Necessity, and what a noble Contrivance this of Gravity is, for keeping the several Globes of the Universe from shattering to Pieces, as they evidently must do in a little Time by their swift Rotation round their own Axes[b]. The Terraqueous Globe particularly, which circumvolves at the rate of above 1000 Miles an Hour[c], would by the centrifugal force of that Motion, be soon dissipated and spirtled into the circumambient Space, was it not kept together by this noble Contrivance of the Creator, this natural inherent Power, namely, the Power of Attraction or Gravity.

And as by this Power our Globe is defended against Dissipation, so all its Parts are kept in their proper Place and Order. All material Things do naturally gravitate thereto, and unite themselves therewith, and so preserve its Bulk intire[d]. And the fleeting Waters, the most unruly of all its Parts, do by this means keep their constant æquipoise in the Globe[e], and remain in _that Place which_, the Psalmist saith, _God had founded for them; a bound he had set, which they might not pass; that they turn not again to cover the Earth_, Psal. civ. 8, 9. So, that even in a natural Way, by virtue of this excellent Contrivance of the Creator, the Observation of the Psalmist is perpetually fulfilled, _Psal._ lxxxix. 9. _Thou rulest the raging of the Sea; when the Waves thereof arise, thou stillest them._

To these, and an hundred other Uses of Gravity that I might have named, I shall only just mention another Thing owing to it, and that is _Levity_[f], that, whereby what we call light Bodies swim, a Thing no less useful to the World than its opposite, _Gravity_, is in many Respects, to divers Tribes of Animals, but particularly serviceable to the raising up of Vapours[g], and to their Conveyance about the World.

And now from this transient View of no other than the Out-works, than the bare Appendages of the Terraqueous Globe, we have so manifest a Sample of the Wisdom, Power, and Goodness of the infinite Creator, that it is easy to imagine the whole Fabrick is of a Piece, the Work of at least a skilful Artist. A Man that should meet with a Palace[h], beset with pleasant Gardens, adorned with stately Avenues, furnished with well-contrived Aqueducts, Cascades, and all other Appendages conducing to Convenience or Pleasure, would easily imagine, that proportionable Architecture and Magnificence were within: But we should conclude the Man was out of his Wits that should assert and plead that all was the Work of Chance, or other than of some wise and skilful Hand. And so when we survey the bare Out-works of this our Globe, when we see so vast a Body, accouter’d with so noble a Furniture of Air, Light and Gravity; with every Thing, in short, that is necessary to the Preservation and Security of the Globe it self, or that conduceth to the Life, Health, and Happiness, to the Propagation and Increase of all the prodigious Variety of Creatures the Globe is stocked with; when we see nothing wanting, nothing redundant or frivolous, nothing botching or ill-made, but that every thing, even in the very Appendages alone, exactly answereth all its Ends and Occasions: What else can be concluded, but that all was made with manifest Design, and that all the whole Structure is the Work of some intelligent Being; some Artist, of Power and Skill equivalent to such a Work?

FOOTNOTES:

[a] That there is such a Thing as _Gravity_, is manifest from its Effects here upon Earth; and that the Heavenly Bodies attract or gravitate to one another, when placed at due Distances, is made highly probable by Sir _Isaac Newton_. This attractive or gravitating Power, I take to be congenial to Matter, and imprinted on all the Matter of the Universe by the Creator’s _Fiat_ at the Creation. What the _Cause_ of it is, the _Newtonian Philosophy_ doth not pretend to determine for want of Phænomena, upon which Foundation it is that that Philosophy is grounded, and not upon chimerical and uncertain Hypotheses: But whatever the Cause is, that _Cause penetrates even to the Centers of the Sun and Planets, without any Diminution of its Virtue; and it acteth not according to the Superficies of Bodies (as Mechanical Causes do) but in proportion to the Quantity of their solid Matter; ~and lastly~, it acteth all round it at immense Distances, decreasing in duplicate proportion to those Distances_, as Sir _Isaac Newton_ saith, _Princip._ pag. ult. What useful Deductions, and what a rational Philosophy have been drawn from hence, may be seen in the same Book.

This Attraction, or Gravity, as its Force is in a certain proportion, so makes the Descent of Bodies to be at a certain rate. And was it not for the Resistence of the Medium, all Bodies would descend to the Earth at the same rate; the lightest Down, as swiftly as the heaviest Mineral: As is manifest in the _Air-Pump_, in which the lightest Feather, Dust, _&c._ and a piece of Lead, drop down seemingly in the same Time, from the top to the bottom of a tall exhausted Receiver.

The rate of the Descent of heavy Bodies, according to _Galileo_, Mr. _Huygens_, and Dr. _Halley_ (after them) is 16 Feet one Inch in one Second of Time; and in more Seconds, as the Squares of those Times. But in some accurate Experiments made in St. _Paul_’s _Dome_, June 9. 1710, at the Height of 220 Feet, the Descent was scarcely 14 Feet in the first Second. The Experiments were made in the Presence of some very considerable Members of the Royal Society, by Mr. _Hawksbee_, their Operator, with glass, hollow Balls, some empty, some filled with Quick-silver, the Barometer at 297, the Thermometer 60 Degrees above Freezing. The Weight of the Balls, their Diameters, and Time of the Descent is in this Table.

+----------------------------------+-----------------------------------+
| Balls filled with ☿. | Empty Balls. |
+---------+-------------+----------+---------+--------------+----------+
| Weight. | Diameter. | Time. | Weight. | Diameter. | Time. |
+---------+-------------+----------+---------+------+-------+----------+
| Grains. | Tenth inch. | ½ Secᵈˢ. | Grains. | Inch.| Tenth.| ½ Secᵈˢ. |
+---------+-------------+----------+---------+------+-------+----------+
| 908 | 8 | 8 | 510 | 5 | 1 | 17 |
| | | | | | | |
| 993 | 8 | 8 less. | 642 | 5 | 2 | 16 |
| | | | | | | |
| 866 | 8 | 8 | 599 | 5 | 1 | 16 |
| | | | | | | |
| 747 | 7½ | 8 more. | 515 | 5 nearly | 16½ |
| | | | | | | |
| 808 | 7½ | 8 | 483 | 5 nearly | 17 |
| | | | | | | |
| 784 | 7½ | 8 more. | 641 | 5 | 2 | 16 |
+---------+-------------+----------+---------+------+-------+----------+

The Reason why the heavy, full Balls fell in half the Time of the hollow ones, was the Resistence of the Air: Which Resistence is very ingeniously and accurately assigned by Dr. _Wallis_, in _Philos. Trans._ Nᵒ. 186. And the cause of the Resistence of all Fluids, (as Sir _Isaac Newton_, _Opt._ Q. 20.) is partly from the _Friction_ of the Parts of the Fluid, partly from the _Inertia_ thereof. The Resistence a spherical Body meets with from Friction, is as the right Angle under the Diameter, and the Velocity of the moving Body: And the Resistence from the _Vis Inertia_, is as the Square of that Product.

For a farther Account of the Properties and Proportions, _&c._ of Gravity in the Fall or Projection of Bodies, I shall refer to the larger Accounts of _Galilæus_, _Torricellius_, _Huygens_, Sir _Isaac Newton_, &c. or to the shorter Accounts of Dr. _Halley_ in Philos. Trans. abridged by Mr. _Lowthorp_, Vol. I. p. 561. or Dr. _Clarke_ in his Notes on _Rohault_, _Phys._ 2. c. 28. §. 13, 16. And for the Resistence of Fluids, I refer to Dr. _Wallis_ before-cited, and the _Act. Erudit. Lips._ May 1693. where there is a way to find the Force of Mediums upon Bodies of different Figures.

[b] That the heavenly Bodies move round their own Axes, is, beyond all doubt, manifest to our Eye, in some of them, from the Spots visible on them. The Spots on the Sun (easily visible with an ordinary Glass) do manifest him to revolve round his own Axis in about 25¼ Days. The Spots on ♃ and ♂ prove those two Planets to revolve also from East to West, as Dr. _Hook_ discover’d in 1664, and 1665. And ♀ also (although near the strong Rays of the Sun) hath, from some Spots, been discovered by Mr. _Cassini_, in 1666, and 1667, to have a manifest Rotation. _V._ _Lowth. Abridg._ Vol. 1. p. 382, and 423, 425. And such Uniformity hath the _Creator_ observ’d in the Works of Nature, that what is observable in one, is generally to be found in all others of the same kind. So that since ’tis manifest the Sun, and three of his Planets whirl round, it is very reasonable to conclude all the rest do so too, yea, every Globe of the Universe.

[c] The Earth’s Circumference being 25031½ Miles, (according to _Book II. Chap. 2. Note (a)._) if we divide that into 24 Hours, we shall find the Motion of the Earth to be nearly 1043 Miles in an Hour. Which, by the by, is a far more reasonable and less rapid Rate, than that of the Sun would be, if we suppose the Earth to stand still, and the Sun to move round the Earth. For according to the Proportions in _Note (e)_, of the preceding Chapter, the Circumference of the _Magnus Orbis_ is 540686225 _English_ Miles, which divided by 24 Hours, gives 22528364 Miles in an Hour. But what is this to the Rapidity of the fixt Stars, if we suppose them; not the Earth, to move? Which is a good Argument for the Earth’s Motion.

[d] _Nihil majus, quàm quòd ita stabilis est Mundus, atque ita cohæret ad permanendum, ut nihil nè excogitari quidem possit aptius. Omnes enim partes ejus undique medium locum capessentes, nituntur æqualiter: maximè autem corpora inter se juncta permanent, cum quodam quasi vinculo circumdata colligantur: quod facit ea natura, quæ per omnem mundum omnia Mente, & Ratione conficiens, funditur, & ad medium rapit, & convertit extrema_, Cic. de Nat. Deor. l. 2. c. 45.

[e] _Eâdem ratione Mare, cùm supra terram sit, medium tamen terræ locum expetens, conglobatur undique æqualiter, neque redundat unquam, neque effunditur._ Id. paulo post.

[f] That there is no such Thing as _positive Levity_, but that Levity is only a less Gravity, is abundantly manifested by the acute _Seig. Alph. Borelli de Mot. à Grav. pend._ cap. 4. See also the Annotations of the learned and ingenious Dr. Clark on _Rohaulti Phys._ p. 1. c. 16. Note 3. Also the Exper. of the _Acad. del Cimento_, p. 118, &c. Dr. _Wallis_’s _Disc. of Gravity and Gravitation before the Royal Society_, Nov. 12. 1674. p. 28, _&c._

[g] I have before in _Note (a), Chap. 3._ shewn what _Vapours_ are, and how they are rais’d. That which I shall here note, is their Quantity: Concerning which the before-commended Dr. _Halley_ hath given us some curious Experiments in our _Phil. Transact._ which may be met with together in Mr. _Lowthorp_’s _Abridg._ Vol. II. _p. 108._ and _126._ Mr. _Sedileau_ also at _Paris_ observed it for near three Years. By all their Observations it appears, that in the Winter Months the Evaporations are least, and greatest in Summer, and most of all in windy Weather. And by _Monsieur Sedileau_’s Observations it appears, that what is raised in Vapours, exceeds that which falleth in Rain. In the seven last Months of the Year 1688, the Evaporations amounted to 22 Inches 5 Lines; but the Rain only to Inches 6⅓ Lines: In 1689, the Evaporations were 32 Inches 10½ Lines; but the Rain 18 Inches 1 Line: In 1690, the Evaporations 30 Inches 11 Lines; the Rain 21 Inches ⅓ of a Line. _Vid._ _Mem. de Math. Phys. Ann. 1692._ p. 25.

If it be demanded, What becomes of the Overplus of Exhalations that descend not in Rain? I answer, They are partly tumbled down and spent by the Winds, and partly descend in Dews, which amount to a greater quantity than is commonly imagined. Dr. _Halley_ found the descent of Vapours in Dews so prodigious at St. _Helena_, that he makes no doubt to attribute the Origine of Fountains thereto. And I my self have seen in a still, cool Evening, large thick Clouds hanging, without any Motion in the Air, which in two or three Hours Time have been melted down by Degrees, by the cold of the Evening, so that not any the least Remains of them have been left.

[h] See _Book II. Chap. 3. Note (c)._