It's pretty well known that Mark Twain was rather vitriolic against Jane Austen, saying things like:
I go so far as to say that any library is a good library that does not contain a volume by Jane Austen. Even if it contains no other book.
Every time I read 'Pride and Prejudice' I want to dig her up and beat her over the skull with her own shin-bone.
But I'd like to know if, in his criticisms of her, he ever provided actual substantive criticisms of her books. Preferably more specific than "she's a terrible writer" or "I hate all her characters." Did he give real reasons for his dislike?