The Mezzanine

But isn't the metre beautiful?

*ducks thrown book*

Edited to add that I'd parse it like this:

Heaven touches our prince's new palace,
More splendid than the sun has seen on all earth
Though this house, Augustus, which the peak of the stars [i.e. the sun] hits
Is equal to heaven, it is still lesser than its master [i.e. Augustus].

I don't know Latin grammar, but that's what I'm getting from your word for word.