"Well, what is to be done now, John?" I asked; "we have tried two courses without any effect!" "I would suggest, Professor, that we should go up higher," he replied, "so as to enable us to try again from another altitude, then, perhaps, we may pass above the obstacle." "A good thought that, John!" I cried. So up we went, the machinery working all right now, and our spirits rose as we soared higher; but, alas! after rising a few hundred yards, the machines began to slow down, and soon stopped altogether. "The de'il himself must be taking a hand in this business!" exclaimed M'Allister, "for this beats the worst experience I ever had! We can't go up, we can't go down, and we can't go forward! Whatever can we do, Professor? You're a scientific man; can't you suggest something which might help?" "It's a profound mystery to me, M'Allister," I replied, "but we certainly do not want to remain hung up in space, so I suggest you should try several different courses. Surely, in some direction we shall find a way out of this, and get to our destination." This plan was tried, M'Allister doggedly setting his course first in one direction, then in another, and trying to put on enough power to force the vessel along; but time after time we came to a standstill after moving very slowly for a short distance. "It looks as though we were to be hung up here indefinitely," said John. "We do not seem able to get through this mysterious obstacle, whatever it may be, or whatever course we may try." "Oh, we've not tried all points yet," I said. "We must not give up now we have got so close to the object of our trip. Take a fresh course, M'Allister." He took a fresh course, and another after that, but with exactly the same result. I had never seen M'Allister in such a perturbed state before; he actually trembled all over with the intensity of his feelings, and his face had an expression of grim determination such as I should imagine might be seen on the face of a soldier at bay with his back to a wall, and fighting for his life against overwhelming numbers of assailants. "My word!" he exclaimed, "yon's Mars, and here's us, but it doesn't seem as if we should ever come together. Losh mon, bonnie Scotland for ever! Here goes for another try!" and he switched on the current again with a vicious pull. We watched the machines with intense anxiety, wondering whether this new course would be any better than the others we had tried--whether the machines would keep moving, or slow down and stop as before. No, we kept moving; and soon it was evident we were gaining speed rapidly. "Hurrah, hurrah!" I cried in exultation. "We are doing it this time. Slow down, M'Allister, we are going too fast now!" "Scotland for ever!" he shrieked. "That did it, Professor!" Strangely enough, John, usually the most excitable member of our party, was the calmest of the three, and simply remarked quietly, "We've done it this time."