leave this soyl, and Ile conduct you to a place retir'd, which I by art 
have rais'd, call'd Merlins Bower, there shall you dwell with solitary
sighs, with grones and passions your companions, to weep away 
this flesh you have offended with, and leave all bare unto your
aierial soul, and when you die, I will erect a Monument upon the 
verdant Plains of Salisbury, no King shall have so high a sepulchre,
with pendulous stones that I will hang by art, where neither Lime 
nor Morter shalbe us'd, a dark Enigma to the memory, for none
shall have the power to number them, a place that I will hollow 
for your rest,
Where no Night-hag shall walk, nor Ware-wolf tread, 
Where Merlins Mother shall be sepulcher'd.
Perfect Anagram—same letters, same amount.
Artesia to art-saie is a perfect anagram; say appears in the First Folio as saie sometimes. Artesia is personified art-of-saying in The Birth of Merlin. This is hinted when she, "a woman Orator," appears the first time in the play.
[Flourish Cornets. Enter Artesia with the Saxon Lords.]To solve the content of Artesia's art of saying, we need to consider all things related to Artesia, including Ostorious, Octa, gentlewoman with an artificial Crab, and how Artesia and Saxons win and lose in the play. This play has no soul without solving this.
DONOBERT. What's here, a woman Orator?
Both-way Anagram—same letters, different amount.
Salisbury to sally's-bury is a both-way anagram. Sally here means a sudden rush (out) from a besieged place upon the enemy (OED). Wilton poets select Merlin because Stonehenge is located in Wiltshire, Salisbury, not far from Wilton, and they create characters like Jone Go-too't, Clown, etc. to seal their own story, not a coincidence.
One-way Anagram—different letters, different amount.
Perfect and both-way anagram are hard to make, easy to break; they are unrealistic in sealing names. Good riddlers must provide enough clues, and if the base is large, they must have some guidelines, else readers couldn't even know where are the riddles located. They won't tell us the guidelines, but we can conclude by enough samples, and using them so solve more riddles; e.g., a person's true name is sealed via one-way anagram around a character's name or nature. This happens especially to the unnecessary naming.
Merlin's Bower is a place created by the author. It can easily spell Mary Sidney by combining words around it.
If we expand the range to "call'd Merlins Bower, there shall you dwell," we can spell Mary Sidney Herbert, Wilton House.
This is one sample to solve Merlin's Bower as Wilton House. We need many samples to build a guideline.
Mary, Philip Sidney is a one-way anagram of "Monument upon the verdant Plains of Salisbury." From the diagram we can see the author's logic, that after the main words are placed, missing letters will be mended by selecting usually "odd" words; in this case is verdant to mend the r and d.
Another guideline is to seal information at the beginning or end of a play or paragraph. The last line of Merlin's prophecy is "Where Merlins Mother shall be sepulcher'd."
These diagrams are done by computer; missing letters will be grayed automatically. We can see most letters are concentrated in "Merlin's Mother." This one-way anagram still lacks of letter d and u; "sepulcher'd" provides the two.
Merlin's page Sparrowhawk
Sparrowhawk can spell Shakespeare except letter e, which is quite easy to mend; however, this word can spell William Shaksepeare with Merlin isn't easy at all.
CLOWN. I do feel a fault of one side, either it was that Sparrowhawk, or a Cast of Merlins, . . .
This line says William Shakespeare is Merlin's page. The line "or a Cast of Merlins" isn't really needed, a little bit suspicious; so we expand the Sparrowhawk.
"Cast" provides the needed letter c and t to spell Christopher Marlowe, who always thought he represented Shakespeare, the major part of it. This one-way anagram would be meaningful when the author of this paragraph is Marlowe himself.
Anselme, Bishop of Winchester
The Hermit "Anselme, after Bishop of Winchester" can spell Christopher Marlowe. There is no Bishop of Winchester in the play.
Hermit and Merlin overlap four letters, e, r, m, i.
Anselme and Merlin overlap also four letters, n, e, l, m.
Merlin is a one-way anagram of Hermit Anselme. From the diagram we can see Anselme provides letter n and l to spell Merlin. From "Hermit Anselme" we can derive Merlin, but from Merlin we cannot derive Anselme; i.e., Merlin includes Anselme, or Christopher Marlowe.