“But, after Saturn—what then?” was the next inquiry of his impatient audience. “After Saturn? Well, we’ll visit Jupiter. A funny place that is, too, where the days are only nine hours and a half long—a good thing for the lazy fellows—and the years, would you believe it—last twelve of ours, which is fine for folks who have only six months to live. They get off a little longer by that.” “Twelve years!” ejaculated the boy. “Yes, my youngster; so that in that country you’d be toddling after your mammy yet, and that old chap yonder, who looks about fifty, would only be a little shaver of four and a half.” “Blazes! that’s a good ‘un!” shouted the whole forecastle together. “Solemn truth!” said Joe, stoutly. “But what can you expect? When people will stay in this world, they learn nothing and keep as ignorant as bears. But just come along to Jupiter and you’ll see. But they have to look out up there, for he’s got satellites that are not just the easiest things to pass.” All the men laughed, but they more than half believed him. Then he went on to talk about Neptune, where seafaring men get a jovial reception, and Mars, where the military get the best of the sidewalk to such an extent that folks can hardly stand it. Finally, he drew them a heavenly picture of the delights of Venus. “And when we get back from that expedition,” said the indefatigable narrator, “they’ll decorate us with the Southern Cross that shines up there in the Creator’s button-hole.” “Ay, and you’d have well earned it!” said the sailors. Thus passed the long evenings on the forecastle in merry chat, and during the same time the doctor went on with his instructive discourses. One day the conversation turned upon the means of directing balloons, and the doctor was asked his opinion about it. “I don’t think,” said he, “that we shall succeed in finding out a system of directing them. I am familiar with all the plans attempted and proposed, and not one has succeeded, not one is practicable. You may readily understand that I have occupied my mind with this subject, which was, necessarily, so interesting to me, but I have not been able to solve the problem with the appliances now known to mechanical science. We would have to discover a motive power of extraordinary force, and almost impossible lightness of machinery. And, even then, we could not resist atmospheric currents of any considerable strength. Until now, the effort has been rather to direct the car than the balloon, and that has been one great error.” “Still there are many points of resemblance between a balloon and a ship which is directed at will.” “Not at all,” retorted the doctor, “there is little or no similarity between the two cases. Air is infinitely less dense than water, in which the ship is only half submerged, while the whole bulk of a balloon is plunged in the atmosphere, and remains motionless with reference to the element that surrounds it.”