I see Miss Austen being very precipitious in this absolutely cliff-hanger of a turn of events in Ch 49. All or nothing it was to be for Mr. Knightley.

Although Emma, throughout the story, has gone on some wild flights of fantasy and imagination, nobody has yet accused her of being dull or slow-to-comprehend. I give this little quote again from Ch 49:

".....While he spoke, Emma's mind was most busy, and, with all the wonderful velocity of thought, had been able -- and yet without losing a word -- to catch and comprehend the exact truth of the whole; to see that Harriet's hopes had been entirely groundless, a mistake, a delusion, as complete a delusion as any of her own -- that Harriet was nothing; that she was every thing herself...."

Mr. Knightley's handling of his offer was masterful because he was already so intimately acquainted with Emma's quick and fertile intelligence and hit a grand slam. In a twinkling of an eye, she put Harriet aside, to be dealt with later. If Emma (God forbid) had refused Mr. Knightley's offer, would he have tried again later on? I'm inclined to doubt it. (No proof to offer here, just my hunch)

I can hardly wait for the final chapters to revisit these two.....I have so much more to say about them.