8 The INTRODUC'TIONi

The Pla-nets turnround theSun.

Sun: For if they had, all Parts of themwould be lucid, without any Darkness or• Shadow. The Planets are likewise provedto be Globular , because let what Part soeverof them be turned towards the Sun, itsBoundary, or the Line separating that Partfrom the opposite, always appears to be Cir-cular ; which could not happen if they werenot Globular.

II. That the Earth is placed betwixt theOrbs of Mars and Venus , and that 5 , ? ,cf, % , and T?, do all turn round the Sun;is prQved from Observations as follow:

r. Whenever Venus is in Conjunctionwith the Sun, that is, when (he is in thesame Direction from the Earth, or towardsthe same Part of the Heavens the Sun is in;she either appears with a bright and roundFace like a full Moon, or else disappears ;or if she is visible, she appears horned likea new Moon : which Phenomena couldnever happen, if 5 did not turn round theSun, and was not betwixt him and theEarth: For since all the Planets borrowtheir Light from the Sun, it is necessary thatV ’s lucid Face should he towards the Sun;and when she appears fully illuminated,she shews the same Face to the Sun andEarth; and at that Time she must be aboveor beyond the Sun, for in no other Positioncould her illuminated Face be seen from theEarth. Farther, whep she disappears, or,