"...According to his own story, as told in Roughing It, he was
dubious of his ability to interest an audience and fearful of
failure..." ("Mark Twain Speaking",ed by Paul Fatout. Univ of Iowa
Press, 1976: xvi)
--Haven't got a copy of Roughing It, but judging by Fatout's note, it
might be a good place to check if you haven't already.

Justine Roberts
Mill Valley, CA