I've recently been taking notes from Cardwell's "Twins of Genius",
particularly in regards to the deteriorating relationship between Twain
and Cable.  Twain knew from the outset that Cable would not travel on
the Sabbath but it was not until the final week or two of the tour that
Cable became the "pitifulest human louse" he had ever known.  Cardwell
describes several other traits that combined to end the tour but I
wonder if Twain's memory of the inhuman treatment visited upon the
horses by the Sabbath keeping Pilgrims in Palestine didn't color his

Just a thought.