"Besides," he remarked, "what do we know of the currents? This is not the old Atlantic. If I could feel the Gulf Stream I'd know whereabouts I was, but these currents come from all directions, and a man might as well try to navigate in a tub of boiling water."
"But we can, at least, keep working eastward," said Cosmo. "My idea is first to make enough southing to get into the latitude of the Sahara Desert, and then run directly east, so as to cross Africa where there are no mountains, and where we shall be certain of having plenty of water under our keel.
"Then, having got somewhere in the neighborhood of Suez, we can steer down into the region of the Indian Ocean, and circle round south of the Himalayas. I want to keep an eye on those mountains, and stay around the place where they disappear, because that will be the first part of the earth to emerge from the flood and it is there that we shall ultimately make land."
"Well, we're averaging eight knots," said the captain, "and at that rate we ought to be in the longitude of the African coast in about twenty days. How high will the water stand then?"
"My gages show," replied Cosmo, "that the regular fall amounts to exactly the same thing as at the beginning—two inches a minute. Of course the spouts increase the amount locally, but I don't think that they add materially to the general rise of the flood. Two inches per minute means 4,800 feet in twenty days. That'll be sufficient to make safe navigation for us all the way across northern Africa. We'll have to be careful in getting out into the Indian Ocean area, for there are mountains on both sides that might give us trouble, but the higher ones will still be in sight, and they will serve to indicate the location of the lower ranges already submerged, but not covered deeply enough to afford safe going over them."
"All right," said Captain Arms, "you're the commodore, but if we don't hang our timbers on the Mountains of the Moon, or the Alps, or old Ararat, I'm a porpoise. Why can't you keep circling round at a safe distance, in the middle of the Atlantic, until all these reefs get a good depth of water on 'em?"
"Because," Cosmo replied, "even if we keep right on now it will probably take two months, allowing for delays in getting round dangerous places, to come within sight of the Himalayas, and in two months the flood will have risen nearly 15,000 feet, thus hiding many of the landmarks. If we should hold off here a couple of months before starting eastward nothing but the one highest peak on the globe would be left in sight by the time we arrived there, and that wouldn't be anything more than a rock, so that with the uncertainty of our navigation we might not be able to find it at all. I must know the spot where Tibet sinks, and then manage to keep in its neighborhood."
That ended the argument.
"Give me a safe port, with lights and bearings, and I'll undertake to hit it anywhere in the two hemispheres, but blow me if I fancy steering for the top of the world by dead reckoning, or no reckoning at all," grumbled the captain.
At night, of course, they had not even the slight advantage that their observations of the probable place of the sun gave them when it was above the horizon. Then they had to go solely by the indications of the compass. Still, they forged steadily ahead, and when they got into what they deemed the proper latitude, they ran for the site of the drowned Sahara.