like a Sky Rocket, while they fpend themselves, fo this
Meteor feemed like a fhooting or falling Star, till it be-
came extinguished; according to the Poet.
Thus oft before tempeftuous Winds arise,

The feeming Stars fall headlong from the Skies,
And fhooting thro' the Darkness, gild the Night
With fweeping Glories, and long Trails of Light.

Thus alfo Manilius ;

DRYDEN'S VIRGIL.

But fill, when wand'ring Stars adorn the Night,
The falling Meteors draw long Trains of Light ;
Like Arrows foot from the celestial Bow,

They cut the Air, and ftrike our Eyes below.

LIB. I.

DIALOGUE

V.

Of an ECLIPSE of the SUN.

Euphrofgne.

Have been very anxious about the Weather To-day, how it might chance to fall out, on Account of the Eclipfe of the Sun that is to be this Afternoon; but it is at prefent fine, and I hope the Clouds will forbear, and permit us the extraordinary Sight, efpecially now you are here.

Cleon. I believe it will be a fine Day throughout: It will begin juft at 39 Minutes after Three o'clock, against which Time I will get the Telescope and darkened Chamber in Readiness for the Observation.

Euphrof. What I have often wondered at, Cleonicus, is, how any Body can tell when an Eclipfe will happen fo long before-hand, and to fuch Exactness of Time.

Cleon. It does feem wonderful to those who know not the Principles they go upon but I do affure you, my Euphrofyne, the Aftronomer can foreknow and predict the Time of an Eclipfe to a Minute, with the fame Eafe, and in the fame Time as you can raise a MincePye.

2

H

Euphrof. Indeed! Well, that old Saying is good, All Things are eafy when underflood. But, pray, what is the Meaning of the Word Eclipfe?

Cleon. The very Nature of the Thing is implied in the Word, which is of Greek Original, and fignifies a Defect or Deficiency; and therefore is properly applied to exprefs the Lofs of Light in the Sun or Moon. The Word Eclipfe alfo fignified to faint, fwoon, or be fick; and was generally applied to People when in a fainting Fit, or dying away; and the ancient ignorant Heathens, thinking this to be the Cafe with the Sun and Moon at fuch Times, used to say they were eclipfed. Thus Lucretius;

Eclipfes may be folv'd a thousand Ways,

For if the Moon can flop defcending Rays
By thrusting her dark Self between, and fo
Bring Judden Shade, and Night on all below;
Then give me Reafons why there cannot be
Another Thing, too dark for us to fee,
And fit to flop the Rays, as well as fhe?
Or, why the circling Sun, in paffing by
Some venomous Places of the neighbouring Sky,
May not grow fick, and pale, and almost die?
Thofe paft, grow well, regain his former Light?
Thus fometime make us Day, and fometime Night.

}

BOOK V.

Thus Virgil alfo in his Petition to the Muses;
Give me the Way of wand'ring Stars to know,
The Depths of Heav'n above, and Earth below;
Teach me the various Labours of the Moon,
And whence proceed th Eclipfes of the Sun.

GEORG. II.

Euphrof. I could heartily join with Virgil in his Prayer, but I am afraid my Stars never defigned me for an Aftronomer good enough to understand the Nature of Ecliples.

Cleon. Don't think ill of your Stars till you know you have Reason; I believe there are few Ladies who have not Intellects fufficient to understand the general Doctrine of Eclipfes, especially as to the Manner of them, without the mathematical Principles, on which the Theory depends.

Euphrof. I fhall be glad if I can be an Inftance of this to the reft; I prefume you must go to Scheming again, if you intend I fhould understand any Thing of the Matter.

See

Cleon. Without Figures, or Schemes, none can underftand it; but with thofe Helps they eafily may. here a little Draught of an Eclipfe of the Sun and Moon.

Euphrof. I do; and can affure you that it appears at first Sight fo eafy and expreffive, that I am in Hopes I fhall give you but little Trouble in the Explication. I fee the Earth in its Orbit about the Sun, and the Moon in two Pofitions in her Orbit about the Earth; in the firft, fhe is between the Earth and Sun, and casts her Shadow upon the Earth; in the latter, the is involved in the Shadow of the Earth, which is then interpofed between her and the Sun.

Cleon. You conceive a very good Notion of the Thing in general, and a few Particulars explained will give you a good Idea of both Kinds of Eclipfes. And first, for an Eclipfe of the Sun, you fee that is occafioned by the New Moon coming between the Earth and Sun, by which Means her Shadow often falls upon the Earth in some Part, as at C; for to an Inhabitant at C, the Moon will appear to cover the whole Face of the Sun very nearly, and so cause what we call a total Eclipfe of the Sun. This is evident by drawing the Lines CMD and COE, (from an Eye at C,) touching the two extreme Parts of the Moon, M and O; for those Lines continued to the Sun will very nearly include his whole Body, as you see; and confequently it can't be seen by the Eye at C.

Euphrof. I understand you pretty well as to that; but you feem to intimate that the Moon does not wholly and entirely eclipfe the Sun's Body, when she is directly be

tween us and him.

Cleon. No, fhe does not always; because her apparent Face or Difk is fometimes fomewhat lefs than the apparent Face of the Sun, the Proportion being about 31 to 32; and therefore in a central Eclipfe of the Sun, there will be fometimes a very small Annulus, or Ring, on the Sun's Extremity not eclipsed, but visible, as you will fee ere long.