ference of the Earth will amount to 5400, and its Diameter to 1718 Dutch Leagues.

III. This being multiply'd with 12000, the Product of Dutch Leagues between the Sun and Earth, will be 21.616,000.

IV. This being divided by 50, or the Miles that a Ship will fail in a Day, or a Horfe run, the Amount will be 412,320 Days, or about 1129 Years.

I thought I could not do amifs in being fomething the more large upon this Subject, and in fhewing the Sun's Distance from the Earth after more than one manner; fince Mankind are wont, upon this Occafion, to reprefent to themselves a Giant like a Dwarf; and the great Firmament, and those glorious Bodies which it contains, and especially the Sun, with refpect to its Magnitude and Distance, incomparably fmaller than they really are, and confequently make the dreadful Power of the CREATOR, Contemptible instead of wonderful and infinite.

SECT. XIX. The Swiftnefs of LIGHT.

LET the Atheist now go on with us, and contemplate that Wonder of all Wonders, that furprizing Creature the LIGHT, in its Properties only, fo far as they are known to us, and in the first Place its unconceivable, and (if it had not been proved experimentally, its altogether) incredible Velocity.

It may perhaps appear ftrange to many, and even not to be admitted by moft, if we fhould affirm that Light requires fome Time for the Parts of it to defcend fucceffively from the Sunto us, and in that manner to be emitted from all Parts of that Glorious Body: Forafmuch as the chief Philosophers of the laft Age, and many

others

others of this, to whom the latest Obfervations of the Aftronomers are not yet known, have thought, and with great Appearance of Truth too, that Light moved much after the fame manner as a Stick lying between the Sun and us, whereof one End being protruded from the Sun, the other in an inftant, and without any Space of Time, would be likewife moved; fo that properly, and according to this Hypothefis, the Light does not come down to us from the Sun, but that which is near and about us is only put into a continual Motion by the Sun, or by the Intermediation of their fuppos'd cæleftial Matter. But they that are of this Opinion, will be yet much more fhock'd, if we fhould tell them, that this Light is not only derived to us continually from the Sun, and that it requires fome Time to pass to us, but even that it is protruded with so great a Swiftness, that it does not take up more than half a Quarter of an Hour, or about 7 Minutes to pass from the Sun to us, that is to say, to run fo many Millions of Miles.

SECT. XX. An Experiment to prove that Light really moves and comes from the Sun.

AN actual Proof that Light moves, and that even when the Rays of it are collected in any Quantity, it will protrude Bodies it meets in its Course, and, as it were, blow them away, may be found in the Hiftory of the Royal Academy of Sciences, 1708, p. 25. where Mr. Homberg relates, That a light Matter, fuch as the Amianthus, or Plume-Allum, being fuddenly brought into the Focus of a Burning-Glafs, upon a Wood-Coal, was driven off by the concurring Rays of Light; and that the Spring of a Watch, one End of which faften'd in a piece of Wood, being like

wife placed in the Focus of a Glafs of twelve or thirteen Inches, the Rays ftruck against the loose End of it, and caused it to move backwards and forwards, juft as if it had been thrust with a Stick.

Now this does undeniably prove a great Swiftnefs of Light; yet this amazing Course of it, as it furpaffes all Imagination, fo with many would it exceed all Appearance of Truth, were it not that the ten Years Obfervations made by Mr. Romer, upon the Eclipfes of Jupiter's Satellites, had put this Matter so much out of Difpute and Doubt, that the greatest and most accurate Mathematicians have been forced to admit it upon the Strength of those Experiments.

It fhall fuffice here, that we may not fwell this Difcourfe too much, to produce only the Testimony of Sir Ifaac Newton, tho' we could likewife add many others; these are the Words of that Gentleman in his Princ. Philof. p. 231. Prop. 96. Lib. 1. in the Scholium. For that Light is pushed on fucceffively, the Parts of it following each other, and that it paffes from the Sun to the Earth in the Space of ten Minutes (in the fecond Edition he has alter'd it to feven or eight Minutes) is now certain by the Appearances of Jupiter's Satellites, and confirmed by the Obfervations of feveral Aftronomers.

And when afterwards he publifhed his Opticks, which are proved and illuftrated by a Number of wonderful Experiments, we find him fpeaking after this Manner, in the Eleventh Propofition of the Second Book of the Third Part, p. 236. The Light is tranfmitted in a certain Space of Time from the illuminating Body, and employs about Jeven or eight Minutes in its Course from the Sun to the Earth: Whereupon he adds the Proof, the firft Words of which are, This was firft obferved by Romer, and afterwards by others, by Means of the Eclipfes of VO L. III. A a a

Jupi

Jupiter's Satellites: In his fecond Edition of his Opticks, he only allows about feven Minutes for this Paffage of the Light.

They that defire to fee this more largely proved, may confult Mr. Huygens, in his Treatife of Light; Mr. Whifton in his Pralect. Aftronom. and others. Befides, that the Impoffibility of the contrary Hypothefis has been already fhewn both by Newton and Huygens.

It is fufficient for us, fince we cannot ftand here to defcribe the Particulars of Aftronomy, to fhew that this has been proved to be an uncontestable and certain Argument by the moft accurate Inquirers into the Nature of Light, and that the boldest Atheists have no Reason to doubt thereof, unless they understand nothing of Mathematicks, or are ignorant of the latest Discoveries about the Properties of Light; or if they would be pleased to read the aforemention'd Aftronomical Lectures of Mr. Whifton, p. 229, and 230, where the Rectilinear progreffive Motions of the little Particles of the Light are largely handled and proved beyond all Doubt; and where he fhews, according to the niceft Obfervations, that in half a quarter of an Hour's time, the Light paffes thro' all that Space that is between the Sun and the Earth. And this being allowed, let them reflect with themselves, whether it be credible, that it is by meer Chance, and without any Direction, that Bodies protruded with fuch an amazing Swiftnefs, can always obey fo many Laws without once varying in their unconceivable Progress, as it has been obferved with refpect to Light upon fo many Occafions; of which more hereafter.

SECT.

SECT. XXI. What would be the Confequence, if the Rays of Light Should become a Solid Body, and the Parts thereof adhere to each other.

ISHALL here add, that I have been exceedingly affected with the Confideration of the dreadful Velocity of Light, as often as I thought that if once fo many Particles thereof should adhere to each other, fo as to compofe a little Body, weighing no more than the tenth part of a Grain, they would exert as great a Force by the Swiftnefs of their Motion in ftriking upon any earthly Body, as a Bullet of twelve Pound Weight fhot out of a great Cannon.

Now that it is not impoffible that Light should become a folid Body, feems to be proved by that Matter which we at prefent call a Phofphorus, which feems to confift altogether, or for the most part, of a combined Fire or Light; forafmuch as if we put the fame into Oil of Cloves, the Light thereof cleaves to the Oil, and caufes it to fhine, as it is known to the Chymifts.

And now, that no body may think fuch a dreadful Force improbable, which we fuppofe to be in the defcending Light, in the aforefaid Circumstances, let him fuppofe:

I. That Light paffes in half a Quarter of an Hour, or 450 Seconds from the Sun to the Earth, which has been fhewn above to amount to the Number of 78,463.128,000 French Fathoms.

II. It follows then, that this being divided by 450, the Light paffes thro' 174.362,506 thereof in one Second or Pulfe. Let us fuppose it, for the fake of a round Number, to be just 174.362,500.

III. Now a Twelve-pounder Shot out of a Cannon is found to advance in the same time a hun→ dred of thefe Fathoms. IV. And

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