In the field of Textual Criticism, the word 'autograph' does not refer just to a signature but to a manuscript, traditionally hand-written on parchment or vellum, by either the writer themselves or by a scribe, from dictation.
But I recently came across the word 'authograph' which I assume is being used in the same context as it is used by John Burgon, a renowned textual critic.
The NGram shows its use and it appears to be still a valid, and not archaic, word. But I can nowhere find - anywhere - a dictionary that contains it, either online or at home.
Does this word mean what I think it means (the original handwritten manuscript of an author) or does it mean something else ?