Read it through once

WE reached St. Paul, at the head of navigation of the Mississippi, and there our voyage of two thousand miles from New Orleans ended. It is about a ten-day trip by steamer. It can probably be done quicker by rail. I judge so because I know that one may go by rail from St. Louis to Hannibal--a distance of at least a hundred and twenty miles--in seven hours. This is better than walking; unless one is in a hurry.