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AsTRONOMt,IX. The second is, That Mars ,

and Saturn., hgve each tjiejr Ccnjun$ t0fi ,

d

viction, who cannot fee the Constitutionand the Disposition of the Planetary Orbits, areare above described.

5. But farther : If we divide the Distance . e <JEarth frpm the Sun, viz. the Line S T, into a hud p,

nlsirp frhr 1 OrKitS ^

or a thousand equal Parts, and place the Orbits '

mis and Mercury at the Distance of 8 V — 7 24 '. g (eb M = 388, and then draw T A, T R, to touch l ^ cSOrbits in the Points A and R ; then ’tis plain the Aso ^AT S and R T S will measure the greatest Dist^f^;which either of those Planets can be seen from the h ^

because the visual Ray passing to the Planet in apy csiPart of its Orbit will lie nearer to the Line T ®and therefore strew the Planet nearer the Sun than ^at A or R,. 0 ,

6. Now ’tis found by measuring those Ans eS j! ^metrically in the Diagram, that the Angle ATSDegrees, and R T S = 20, very nearly; and this aS ^exactly with their observed greatest Distances 0 . jjj’j?gation from the Sun in the Heavens. Hence stMercury is so rarely seen, and Venus but at certain 1

of the Year; whereas if the Earth were at rest, ssthe Centre of the Planetary Orbits, those Planets ^be seen in all Positions and Distances from the S ul1 ’j-,every respect like the Moon ; and therefore ’t* s *j„gfectly surprizing, how any Man can resist soph g ia .^cEvidence'of Truth on one hand, and Falfhood ° nother. '

7. We have already shewn, that the apparent ™ t pe

nitude and Brightness of an Object decreases sl fSquare Distance increases ; therefore ’the Magni^Venus seen at V is to that as it appears 'from D 1Proportion of TD 2 to T V 2 , that is, as 1724^ ^ id

or as 36 to 1 nearly. And when Venus is mease*^both those Distances with a Micrometer in a T e ^®

the Numbers thew the perfect Agreement of this S)with Nature itself. ' " .^S

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