MDMD(6): A difficult passage

[Michel Ryckx]

" "Why aye, " --as far projected into the Sea, each will confide, as
Land may go, out blessedly alone upon the furthest Point, nothing beyond
but the uninterrupted planeatry Seas of the 40's, the West Wind Express,
and the Regions of Ice, and the Mystery of the exact Other Pole,-- the
night Fog creeping like quicksilver, all but surrounded by a Waste where
the Seas might grow higher than either Astronomer can imagine without
Fear, set up and waiting for a Southern Star, Lumina of a shapely
Constellation unnam'd, forever below any British Horizon, to culminate."

This whole paragraph, (83.18 -->83.25), though I understand literally
what it says, doesn't make much sense to me, nor can I see it as a
comment on the previous conversation.  Help me.

Michel.