"But I never saw anything that ran by gas that didn't get its back up sometimes. Suppose we allow a month to get up to Mandan--bringing us there by June 22d--call it June 30th. How'd that do? Do you think we can make it--say forty-odd miles a day--or even thirty?" "Sure we can!" said Jesse, stoutly. "Yes--on paper!" repeated Uncle Dick. "Well, there's many a sand bar between here and Mandan, and many a long mile. Lewis and Clark did not get there until October 26th--four months from here. If we allow ourselves one month, we'll only have to go four or five times as fast as they did. I've known a flat bottom 'John boat' do forty miles a day on the Current River of Missouri with only one outboard motor; and that's a six-mile current, good and stiff. Let us not count our chickens just yet, but keep on plugging. I must say Rob is a wizard with the engines, this far, at least. "And now, if we're done with the arithmetic----" "We're not," interrupted Jesse. "I've set down the fish I've caught this far, and it's three wall-eyes and twelve catfish. That's fifteen head of game against their thirty, about!" "Oh! And you want to know, if a boy of your size could catch fifteen head of fish in eight days, how many could we all catch in thirty days? That's getting out of my depth, Jesse! I don't know, but I hope that the gasoline and the catfish both hold out, for they are our main staffs of life just now." They ran up the left bluff of the river, mile after mile, under the edge of the great town whose chimneys belched black smoke, noting railway train after train, their own impudent little motors making as much noise as the next along the water front. Many a head was turned to catch sight of their curious twin-screw craft, with the flag at its bow, and on the stern the name _Adventurer, of America_, but Rob paid no attention to this, holding her stiff into the current and heading in answer to Uncle Dick's signals. At last they lay alongside a little landing to which a houseboat was moored, occupied by a riverman whom Uncle Dick seemed to know. "How do you do, Johnson," said he, as the man poked his head out of the companionway. "You see we're here." "And more'n I'd of bet on, at that!" rejoined the other. "I never expected ye could make it up at all. How long ye been--a month or so?" "A week or so," replied Uncle Dick, carelessly, and not showing his pride in the performance of the party. "You see, we've got double engines and we travel under forced draught, with the stokers stripped to the waist and doing eight shifts a day." "Like enough, like enough!" laughed Johnson, not crediting their run. "Well, what kin I do fer ye here?" "Get our tanks filled. Unpack our boat and store the stuff on your boat so it can't be stolen. Overrun our engines and oil her up. Clean out the bilge and make her a sweet ship." "When?"