Can you help me understand this quote?

I was reading a letter written by Herman Melville (author of Moby ) written to Nathaniel Hawthorne for English cl. One quote in the book sticks out in my mind because I don't really understand what he's meaning to say. He says: "So the product is a final hash, and all my books are botches." WHAT DOES THAT MEAN? Here's a link to the letter if you want context: a href="http://xroads.virginia.edu/~ma96/atkins/cmletter.html" rel="nofollow"http://xroads.virginia.edu/~ma96/atkins/…/a The quote is in the middle of the second paragraph. Thank you SO much.