1 6

Fig. 6 .

Heliccen-trick audGeocentricPlace,what.

The INTRODUCTION:

and of Mercury S J 387: And if the Planets moved round the Sun in Circles, havinghim for their Center, the Distances herefound would be always their true Distances;but as they move in Ellipses, their Distancesfrom the Sun will be sometimes greater, andsometimes less. Their Excentricities arecomputed to be as follows, viz.

r Mercury 80 > of the p arts a .Excent. ot ) Venus c ?, . .

. '■Earth 169Jbove mentioned.

The Distances of the superior Planets,viz. cf, X , and Tj * are found by comparingtheir true Places, as they are seen from theSun, with their apparent Places as they areseen from the Earth. Let She the Sun, the 'jCircle ABC the Earth’s Orbit, AG a Linetouching the Earth’s Orbit, in which we’suppose the superior Planets are seen from .the Earth, in the Points of their Orbits cf,

% , h; and let DEFGH, be a Portion ofa great Circle in the Heavens at an infiniteDistance: Then the Place of Mars seen fromthe Sun is D, which is called his true orHeliocentrick Place ; but from the Earthhe’ll be seen in G, which is called his ap-parent or Geocentrick Place. So likewiseJupiter and Saturn will be seen from the.Sun in the Points E and F, their Heliocen-itrick Places; but a Spectator from the j.Earth will fee them in the Point of theHeavens G, which is their Geocentrick Place,

The