The author of A Tramp Abroad tells us of the rushing stream that flows out of the Arcadian sky valley, the Gasternthal, and goes plunging down to Kandersteg, and how he took exercise by making “Harris” (Twichell) set stranded logs adrift while he lounged comfortably on a boulder, and watched them go tearing by; also how he made Harris run a race with one of those logs.  But that is literature.  Twichell, in a letter home, has preserved a likelier and lovelier story: 

Mark is a queer fellow.  There is nothing that he so delights in as a swift, strong stream.  You can hardly get him to leave one when once he is within the influence of its fascinations.  To throw in stones and sticks seems to afford him rapture.  Tonight, as we were on our way back to the hotel, seeing a lot of driftwood caught by the torrent side below the path, I climbed down and threw it in.  When I got back to the path Mark was running down-stream after it as hard as he could go, throwing up his hands and shouting in the wildest ecstasy, and when a piece went over a fall and emerged to view in the foam below he would jump up and down and yell.  He said afterward that he hadn’t been so excited in three months.  He acted just like a boy; another feature of his extreme sensitiveness in certain directions.

Then generalizing, Twichell adds: 

He has coarse spots in him.  But I never knew a person so finely regardful of the feelings of others in some ways.  He hates to pass another person walking, and will practise some subterfuge to take off what he feels is the discourtesy of it.  And he is exceedingly timid, tremblingly timid, about approaching strangers; hates to ask a question.  His sensitive regard for others extends to animals.  When we are driving his concern is all about the horse.  He can’t bear to see the whip used, or to see a horse pull hard.  To-day, when the driver clucked up his horse and quickened his pace a little, Mark said, “The fellow’s got the notion that we are in a hurry.”  He is exceedingly considerate toward me in regard of everything—­or most things.

The days were not all sunshine.  Sometimes it rained and they took shelter by the wayside, or, if there was no shelter, they plodded along under their umbrellas, still talking away, and if something occurred that Clemens wanted to put down they would stand stock still in the rain, and Twichell would hold the umbrella while Clemens wrote—­a good while sometimes—­oblivious to storm and discomfort and the long way yet ahead.

After the day on Gemmi Pass Twichell wrote home: 

Mark, to-day, was immensely absorbed in the flowers.  He scrambled around and gathered a great variety, and manifested the intensest pleasure in them.  He crowded a pocket of his note-book with his specimens and wanted more room.  So I stopped the guide and got out my needle and thread, and out of a stiff paper, a hotel advertisement, I had about me made a paper bag, a cornucopia like,