Willingly enough the boys joined him. He was busy making a calculation of figures on a piece of paper. The steering wheel was lashed and the compass pointed to indicate that the ship was rushing due north. "We're making satisfying progress," said the professor. "At this rate we will not be long on the journey." "How fast are we moving?" asked Jack. "About fifty miles an hour," replied the inventor. "That is 1,200 miles a day, counting that we run day and night at this speed. But we will hardly do that, not that we could not, for there will be no dangers of collisions up here. I think we have the air all to ourselves. "But there will be contrary winds, and we may be blown off our course. That is the only disadvantage an airship is under. It can't sail against the wind like a ship on the water. Still, we have many advantages. Now I figure that we can count on an average of at least twenty-five miles an hour all day long and part of the night. "We started from about the middle of New York state, and to the north pole would be about 3,000 miles. We ought to make the distance in about five days, or say a week, to be on the safe side. We will move as fast as we can, from now on, though, especially during the daylight." The professor turned some wheels and levers and the speed of the airship increased a little. It was kept at about the same height. The sun was beginning to descend in the west, for it was getting late in the afternoon. Down below, on the earth, the landscape had changed from that of cities and towns to a stretch of dense woods. "Must be near supper time," observed Mark. "Your fright didn't deprive you of your appetite, then?" asked Amos Henderson. "Not a bit," replied the boy. In a few minutes Tom and Bill were preparing a meal of the condensed foods, cooked on the electric stove. Everyone voted the victuals excellent. Then, as night settled down, the bunks were made up and the boys, together with the two farm hands, were glad to seek some rest, for the day had been an exciting one. Washington and the professor agreed to divide the night into two watches, as they were not familiar enough with the workings of the ship to dare to leave it unguarded. The machinery might need attention any moment. The boys and their companions were soon asleep, and no thoughts of their strange position, that of slumbering on an airship high in the atmosphere, disturbed their dreams. The last thing Jack wondered was whether the passing of the _Monarch_ would not be taken by people on the earth for the flight of some giant comet, as it sailed aloft, all lighted up. But he was too tired to pursue this speculation long. Morning dawned without anything unusual having occurred. The ship had been kept going at a slow speed all night, and no accidents happened. Breakfast was served, and then each of the crew took up his duties.