Here’s the quotation, as promised. It’s from letter # 294, on 8 February 1967 to Charlotte and Denis Plimmer, who had interviewed Tolkien for the Daily Telegraph Magazine and sent him a draft of their article in advance of publication. He commented on their quotation of him as saying, “I don’t read much now, except for fairy-stories,” by saying:

“For ‘except,’ read ‘not even.’ I read quite a lot–or more truly, try to read many books (notably so-called Science Fiction and Fantasy). But I seldom find any modern books that hold my attention.”

Tolkien adds a footnote to this:

“There are exceptions. I have read all that E. R. Eddison wrote, in spite of his peculiarly bad nomenclature and personal philosophy. I was greatly taken by the book that was (I believe) the runner-up when The L.R. was given the Fantasy Award: Death of Grass [by John Christopher]. I enjoy the S.F. of Isaac Azimov [sic]. Above these, I was recently deeply engaged in the books of Mary Renault; especially the two about Theseus, The King Must Die, and The Bull from the Sea. A few days ago I actually received a card of appreciation from her; perhaps the piece of ‘Fan-mail’ that gives me the most pleasure.”

As far as the Letters go, unfortunately I can’t find any reference in the index to Verne. The index entry for H.G. Wells turns up only a passing reference to Eloi and Morlocks (#109, 31 July 1947) in a letter about the prospects for publishing The Lord of the Rings.

I’m away from my books at the moment so I can’t give you the quote yet, but somewhere in the Letters there’s a draft of a letter that he wrote in response to a press interview from later in his life. I don’t precisely remember the context, but he mentioned along the way that outside of his professional studies, he read very little other than fairy tales and science fiction, mentioning Isaac Asimov (which he misspelled “Azimov”) by name. If that’s a reading habit that persisted from earlier in his life, rather than one he picked up later, then he may very well have read Wells and Verne as a younger man.

I’ll post the quote and the reference when I get back home in a couple of days…