Númenor in That Hideuous Strength

[Idril Celebrindal]

In That Hideuous Strength by C.S. Lewis, something called Numinor is frequently mentioned, usually alongside Atlantis and Merlin. Is this some kind of a reference to Tolkien's Númenor? In That Hideous Strength, it seems to be some sort of ancient sunken ciy, like Atlantis. Seeing as Tolkien and Lewis were friends, it doesn't seem unlikely that Tolkien would have mentioned the idea of Númenor to Lewis. Perhaps Lewis wished to leave a reference to Tolkien's work, even though Númenor is only mentioned briefly in both THS and LotR? Note that in Lewis' book it is spelled Numinor.
Does anybody know anything about this? Because I am quite befuddled.

 

[Elwing the White]

Actually, I'm pretty sure it does. There is a footnote in the book saying that those who want to know more about Numinor must wait for Professor Tolkien's upcoming book.

 

[Idril Celebrindal]

Actually, I'm pretty sure it does. There is a footnote in the book saying that those who want to know more about Numinor must wait for Professor Tolkien's upcoming book.

Hmm... It appears that my version of the book does not have any footnotes 🤷‍♀️. Do you have the version (I'm assuming you have the book?) with the silver forest and two robed figures on the cover?
Thanks for the info!

 

[Elwing the White]

Oh, the thing is, I don't have a physical copy. 😅

 

[Elwing the White]

Though I'm pretty sure this is what the book says (In the foreword, perhaps?):
"Those who would like to learn further about Numinor and the True West must (alas!) await the publication of much that still exists only in the MSS. of my friend, Professor J. R. R. Tolkien"

 

[Olorgando]

JRRT comments on CSL's use of "Numinor" in four of his letters, no. 131, the 10,000-word monster to Milton Waldman of the publisher Collins in late 1951, in a footnote; no. 169 of 11 September 1955; no. 227 of 05 January 1961; and no. 276 of 12 September 1965.
Letter no. 169 perhaps puts it best:
"Your discovery of 'Numinor' in C.S.L.'s That Hideous Strength is discovery of a plagiarism: well, not that, since he used the word, taken from my legends of the First and Second Ages, in the belief that they would soon appear. They have not, but I suppose now they may. The spelling Numinor is due to his hearing it and not seeing it."