Biography of mark twain video online
[201] The riverboatman's cry was "mark twain" or, more fully, "by the mark twain", meaning "according to the mark [on the line], [the depth is] two [fathoms]"; that is, "The water is 12 feet (3.7 m) deep and it is safe to pass." Twain said that his famous pen name was not entirely his invention. In Life on the Mississippi, Twain wrote.