but being loft, in the Ignorance and Barbarity of fucceeding Ages, it was again retrieved, and maintained by Copernicus, about 200 Years ago; and for that Reafon was called by his Name.

Euphrof. And because they placed the Sun in the Center, it was from thence called the Solar System, I fuppofe.

Cleon. You are right, Sifter; and the Appellation of Newtonian was given it from its being demonftrated in every Part by that Prince of Philofophers, Sir Isaac Newton, who first difcovered the Powers employed by Nature; and by obferving the Phænomena, explained and established by that unerring Rule, all its Laws of Motion. Thus again Sir Richard:

The Mafters form'd in Newton's famous School,
Who does the Chief in modern Science rule,
Erect their Schemes by mathematic Laws,
And folve Appearances with just Applause.

Euphrof. Very a-propos, my Cleonicus; I find yoù are a Newtonian every Inch of you.

Cleon. Yes, and I expect to fee you profelyted to this, not more modish than true Philosophy, before we leave the Subject. I can tell you, Sir Ifaac has no fmall Party among the Principal of the Fair Sex.

Euphrof. I'm glad to hear it; I fhall readily make one of the Number, if his Philosophy be the beft; but I beg leave first to understand it, if I can, Cleonicus.

Cleon. Your Requeft is very rational; one Profelyte of the Understanding is worth twenty of meer Faith in Philofophy. I shall endeavour to give you a just Idea thereof, and its several Parts, by a Scheme which I have drawn up for that Purpose, and which is nearly a true Representation of the Solar System, in which you see the Sun poffeffes nearly the central Point, for Reasons we shall hereafter mention. By the central Force, or Power of Gravity, in the Sun, compounded with a projectile Force, there are found to revolve the fix Planets following, viz. the firft, or nearest Planet to the Sun is Mercury; the next is Venus 9; the third is the Earth, with her Moon; the fourth is Mars; the fifth Jupiter 4; the fixth and laft is Saturnħ; these all move about the central Sun in different Spaces or Pe

rods of Time, and in Orbits that are very nearly circular, or fuch as reprefented in this Scheme.

Euphrof. I obferve you have made the Orbs of the Planets circular, but the Orbit of a Comet, I fee, you have represented as Part of a very long Oval: Do all the Comets go round the Sun in fuch oval Figures?

Cleon. Yes, my Euphrofyne, they all move in Orbits, which are more or less oval, or (as the Aftronomers call it) Elliptical; for what you call an oval Figure, they always call an Ellipfis.

Euphrof. The Learned, 'tis fit, fhould be allow'd to fpeak in a Phrafe above what is vulgar; but I take it then only as uncivil or ungenteel Usage, when they amufe us with unintelligible Terms; fince we ought always to understand what is offer'd us to read. But this by the Way; pray Cleonicus, what do you intend by those small Stars round Jupiter and Saturn, in the Scheme?

Cleon. They are little Moons, which the Aftronomers call Satellites; these light those distant Planets thro' their dreary Way; while others which are nearer the Sun, and have therefore a greater Degree of Light, have none of them, fave our Earth only, which has but one.

Euphrof. Thefe, I prefume, are all the great Bodies which compose our System, because I see no more in the Scheme; but pray, what have you done with all the Stars? Do none of them fall to the Share of our World?

Cleon. They are all at a vast Distance from our System, and make no Part of it; as you will fee hereafter. You will cast your Eye on the Diagram once more, and obferve, that the Bulks, or Magnitudes of the Sun and Planets are there also represented.

Euphrof. I fee it, I believe; does not the Orb of Saturn represent the Face of the Sun, and the several other white Globes the comparative Bignefs of the Planets whofe Names they bear?

Cleon. Yes, my Euphrofyne, they do; they are here drawn in Proportion to the Sun, of more than eight Inches in Diamater, and from thence you obferve how small a Figure even the largest of them all makes in Comparison of that glorious, central, folar Globe.

Euphrof. Small indeed! I am almoft afhamed for our Earth; really 'tis scarce visible in the System. Heavens! what a Bustle

do

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do we Mortals, make about this Globe of Earth, when we fee and confider it alone; but how little a Thing does an Empire or Kingdom, nay, the Earth itself appear, compar'd with the whole System.

Cleon. What you obferve, my Euphrofyne, is very juft; we learn by fuch Reflections one useful Leffon, that Things are great and fmall only by Comparison; in regard to many other Properties of Bodies, you will find that this Doctrine will alfo hold good, as we proceed in our Speculations.

Euphrof. I fuppofe, the Distances of the Planets reprefented in the Print, are in Proportion to those in the Heavens, are they not, Cleonicus?

Cleon. They are fo, as nearly as thofe Distances are at prefent known; but in the Year 1761, when Venus will appear on the Sun's Face, the Distances of the Sun and Planets will be very accurately determined, and not till then. We shall therefore conclude with a View of this Syftem in Sir Richard's poetical Defcription.

This wide Machine the Universe regard,
With how much Skill is each Apartment rear'd;
The SUN, a Globe. of Fire, a glowing Maßs,
Hotter than melting Flint, or fluid Glafs;
Of this our Syftem holds the middle Place.
MERCURIUS nearest to the central Sun
Does in an oval Orbit circling run;
But rarely is the Object of our Sight:
In folar Glory funk, and more prevailing Light.
VENUS the next, whofe lovely Beams adorn,
As well the dewy Eve as opening Morn,
Does her fair Orb in beauteous Order run.
The GLOBE TERRESTRIAL next, with flanting Poles,
And all its pond'rous Laad unwearied rolls.
Then we behold bright planetary Jove,
Sublime in Air thro' his wide Province move.
Four Second Planets his Dominion own,

And round him turn as round the Earth the Moon,

SATURN revolving in the highest Sphere.

With lingʻring Labour finishes his Year.

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DIALOGUE

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