Description based on: v. 2, no. 1 (Jan. 1894); title from cover archive.org
Edit - Since no official answer was provided for the first part of the question, I will disregard that part and score on the basis of players' answers to the second part of the question.
All the sources I've seen say that Gov. Harvey was trying to step from the Dunleith (or Demleith) to the Minnehaha, but none of them indicate that he actually got onto the Minnehaha and then slipped. My interpretation is that the vessel he slipped from had to be the Dunleith.