[Q] Ptolomy supposed two Heavens above that of the fixed Stars, which he called the eighth; viz. a ninth, the Crystalline, and a tenth the Primum Mobile. See Letter the second.
The sacred Sun, above the Waters rais'd,
Thro' Heav'ns eternal, brazen Portals blaz'd;
And wide o'er Earth diffus'd his chearing Ray,
To Gods and Men to give the golden Day.
But how ridiculous and absurd all these Opinions and Conjectures really are, will easily appear, if we but once consider the Nature of an unbounded Æther, and the amazing Property of infinite Space.
This, with what has been said before, will not a little assist your Imagination towards conceiving the Reasonableness of the Notion modern Astronomers are now confirmed in, of their being absolutely so many burning Balls, and which was no doubt, many Years ago, the Opinion of Manilius, as is evident from these Lines in his Poem of the Sphere.
For how can we the rising Stars conceive
A casual Production; or believe
Of the chang'd Heav'ns the oft renascent State