The car rested, during the night, upon an immense plateau, in which there was a deep hollow; its height was scarcely eight hundred feet above the level of the sea. This circumstance gave the doctor some hope, since it recalled to his mind the conjectures of geographers concerning the existence of a vast stretch of water in the centre of Africa. But, if such a lake really existed, the point was to reach it, and not a sign of change was visible in the motionless sky. To the tranquil night and its starry magnificence succeeded the unchanging daylight and the blazing rays of the sun; and, from the earliest dawn, the temperature became scorching. At five o’clock in the morning, the doctor gave the signal for departure, and, for a considerable time, the balloon remained immovable in the leaden atmosphere. The doctor might have escaped this intense heat by rising into a higher range, but, in order to do so, he would have had to consume a large quantity of water, a thing that had now become impossible. He contented himself, therefore, with keeping the balloon at one hundred feet from the ground, and, at that elevation, a feeble current drove it toward the western horizon. The breakfast consisted of a little dried meat and pemmican. By noon, the _Victoria_ had advanced only a few miles. “We cannot go any faster,” said the doctor; “we no longer command—we have to obey.” “Ah! doctor, here is one of those occasions when a propeller would not be a thing to be despised.” “Undoubtedly so, Dick, provided it would not require an expenditure of water to put it in motion, for, in that case, the situation would be precisely the same; moreover, up to this time, nothing practical of the sort has been invented. Balloons are still at that point where ships were before the invention of steam. It took six thousand years to invent propellers and screws; so we have time enough yet.” “Confounded heat!” said Joe, wiping away the perspiration that was streaming from his forehead. “If we had water, this heat would be of service to us, for it dilates the hydrogen in the balloon, and diminishes the amount required in the spiral, although it is true that, if we were not short of the useful liquid, we should not have to economize it. Ah! that rascally savage who cost us the tank!”[3] [3] The water-tank had been thrown overboard when the native clung to the car. “You don’t regret, though, what you did, doctor?” “No, Dick, since it was in our power to save that unfortunate missionary from a horrible death. But, the hundred pounds of water that we threw overboard would be very useful to us now; it would be thirteen or fourteen days more of progress secured, or quite enough to carry us over this desert.” “We’ve made at least half the journey, haven’t we?” asked Joe. “In distance, yes; but in duration, no, should the wind leave us; and it, even now, has a tendency to die away altogether.”