Gustavus Selenus.

Anagram:

Augustes es, Lun’ es.

 As I was making ready to speak at length of Cryptography,
         and to tell how great will become this book
and the author thereof, Pataraean Apollo, pulling me by the
        ear, called my attention, and, reproving me, addressed
me first with these words:  “Why make you ready, poor deluded

wretch, to glorify Gustavus, why Selenus, with empty
 praises.  Augustus is this Gustavus, and Luna this Selenus,
        as name and surname attest the man himself. 
August men august things befit, and cultured Maro’s;
        from the sun alone does Luna take its light.”

 Johannes Honthemius Ubius.

 An Echo, by the Same,
on the same preceding Anagram.

 Is this some AUGUSTUS? – Are we to believe that he was
       born of the stock of nobles?  WAS BORN. 
Is this, then, a Naiad?  YOU SAY.  Why is he called
        LUNA?  Or will his condition be for us hence
more and more clear?  POWER.  Now is this book worthy
       of being rolled and rerolled by you?
I HAVE UNROLLED IT.  If one should by chance deny that?  HE
        DROOPS.  O, of writings a kind and volume RARE!  LIGHT.
Of the sort that flashes from the orbit of the sun?  SO.  Nay, above
       the brightness of the stars I judge this man.  I SAY.  Such light hardly
 does Pheobus afford.  HE IS DULL.  Now does this book by clever art
       teach how to avoid the enemy?  SAFELY.  And to deceive famously?
MAGNIFICENTLY.  And to learn beforehand traps?  TO LEARN.  For it is
       very easy to know by this the wiles of men.  IT IS EASY.  That is, that
you may be able rightly to be on your guard against them.  TRULY. 
       That you may not perish unexpectedly.  THROUGH THESE.