Page:Medical Heritage Library (IA b30513546).pdf/28

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16
Astronomical Dialogues.

the Sun and Planets apparent Motions, if you get a right Notion of it, as this Vid Fig. 1. Figure, which we call an Armillary Sphere, will I think help you to obtain: In order to which you must now imagine your Eye placed within at the Center of the Globe, or on the little Ball there in the Figure which represents the Earth; and that the Spherical Surface of it, on which you see the Stars there painted and gilded were transparent like Glass; so that you could actually see thro' it, not only all the Circles drawn upon it, but also all the Stars above in the Heavens, as they really appear there in a bright Night. And if you imagine further, Madam, that strait Lines were drawn from every Star in the Firmament to your Eye so placed, as before, in the Center of this Globe, those Lines would pass thro' and cut the Spherical Surface of the Globe in proper Points to paint, or to place the Pictures of the Stars upon.

I Think, I conceive you right, said the Lady, so that if there were Holes in the Surface of this Globe in those Places where these Stars are painted upon it, and that my Eye were within at the Center, and the Globe turn'd, so as to conform itself to the present Position of the

Heavens