Who is lost in thought in "I had no glimmer of what was in his mind, nor did he enlighten me, but sat lost in thought..."? [closed]
Solution 1:
Holmes is the one who is lost in thought. It is unambiguous. "(did not) ... enlighten me" and "sat lost in thought" are coordinated VPs using "but", with the same subject in
nor did he enlighten me, but sat lost in thought
And since the subject of "enlighten me" is "he", so must that be the logical subject of "sat lost in thought". Which is to say that the same person who failed to enlighten Watson is the one who sat lost in thought, and that is Holmes.
I believe I am agreeing with @BoldBen in the comments above.