THE Measure by which we ufually gage and compare the Heavenly Bodies, is our Terraqueous Globe; of whofe Dimensions and Bulk we can make a pretty good Eftimate, having tolerably good and accurate Obfervations leading us thereto : the Particulars of which I have had Occafion elsewhere to specify (1).

By these Obfervations it appears that the Diameter of this our Globe is above 79 Hundred Miles; that

(1) Phyfico-Theol. B. 2. ch. 2. In which Place I have made use of Mr. Picart's Measure of the Earth. But notwithstanding the Dif ference be but small, viz. a little above 32 Miles in the whole Diameter of our Globe, yet I fhall make ufe here of our Mr. Nerwood's and Monf. Caffini's Measures, because they agree to almoft a Nicery, and Mr. Caffini's were made (by the King's Command) at greater Distances, with the greateft Accuracy. And according to thefe Measures, the Diameter of the Earth is 7967.7 English Miles, its Surface 199444201 Miles, and its Solid Content 264856000000 Miles.

con

confequently its Surface is a good deal above 199 Millions of Miles, and its folid Content or Bulk near 265 Thousand Millions of Miles. If therefore we should go no farther from Home than our own Globe, a Mass we here have worthy of an Infinite Creator, a Work proclaiming that great Being that made it.

But as vaft a Body as this feems to be, it is much less than many, yea most of the Heavenly Bodies that are visible to us, except two or three of the Planets, which feem to be less than our Globe, namely Mars, whose Diameter is reckoned to be but 4875. English Miles; and the Moon, whofe Diameter is but 2175 Miles; and Mercury, whofe Diameter is 2748 Miles (1); but yet these vaft and a

:

(1) The Number of Miles which I have here, and all along, affigned to the Diameters of the feveral Planets are the mean Numbers between Mr. Flamsteed's in Mr.Wḥifton's Aftro

mazing Bodies too. But for the reft, there is good Reason to imagine their Bulk exceeds that of our Terraqueous Globe. Thus the two fuperiour Planets by far exceed us; Saturn being computed at 93451 Miles in Diameter, and confequently at

womical Lectures, and Mr. Huygens's in his Syft. Saturn. and Cofmotheor. which (as Mr. Whifton firft fuggefted to me) feem to be neareft the Truth. For whereas the Rays of Light when intercepted by the Edge of a Knife or other. Body, are as Sir Ifaac Newton obferves in his Princip. L. 1. Prop.96) somewhat bent, as if attracted from a ftrait Line by that Body; and whereas Mr.Flamsteed's Measures were taken with a Micrometer that pinches or clafps the oppofite Edges of a Planet which would incurvate the Rays oneWay; and Mr.Huygens's were taken with the Interpofition of a thin tapering Plate covering the Planet as far as the extremity of its Face, which would cause. an Incurvation of the Rays the contrary way; therefore Mr.Flamfteed's Measures are as much too little, as Mr. Huygens's are too large, and confequently the Mean between them probably nearest the Truth.

4273

427318300000000 Miles in its Bulk; and Jupiter at 120653 Miles in Diameter,and920011200000000 Miles in Bulk. But yet as amazing Maffes as these all are, yet they are all far out done by that ftupendous Globe of Fire, the Sun; which as it is the Fountain of Light and Heat to all the Planets about it,affording them by his benign Rays, and kindly Influence, the great Pleasures and Comforts of Life; fo doth it as far furpass them in its Bulk; its apparent Diameter being computed at 822148 English Miles, and its folid Content at 29097100ooooooooco Miles, fuppofing the Face we fee of the Sun to be its true and real Globe.

Tus ftupendous are the Magnitudes of the Globes of this our Solar Syfteme. But thefe not all, nor perhaps the moft confiderable Bodies of the Universe. For the fixt Stars, although in Appearance but fo ma

ny

14

The Magnitude of Book T

ny golden or flaming Spots, yet are, with great probability, fuppofed to be so many Suns, furrounded with their respective Syftemes of Planets, as our Sun is; and no lefs in Magnitude, if not greater, (fome of them at leaft) than our Sun is, but only diminished in Appearance by their prodigious Distances from us.

IF now we reflect upon the prodigious Maffes of those many Heavenly Bodies that present themfelves to our View, and many more I fhall fhew are unfeen; what a furprizing Scene do the Heavens afford us of the great CREATOR's Power! a Train of fuch immenfe Bodies, that what lefs than an Almighty Hand could first find Matter fufficient for,and then compofe fuch Magnificent Works! But yet what is the Magnitude of all thefe Bodies to that immense Space in which they are? Which is the next thing to be confidered.

CHAP