However, there was no going back; they must go forward; and, indeed, the doctor asked for nothing better; he would even have welcomed a tempest to carry him beyond this country. But, there was not a cloud in the sky. At the close of the day, the balloon had not made thirty miles.
If there had been no lack of water! But, there remained only three gallons in all! The doctor put aside one gallon, destined to quench the burning thirst that a heat of ninety degrees rendered intolerable. Two gallons only then remained to supply the cylinder. Hence, they could produce no more than four hundred and eighty cubic feet of gas; yet the cylinder consumed about nine cubic feet per hour. Consequently, they could not keep on longer than fifty-four hours--and all this was a mathematical calculation!
"Fifty-four hours!" said the doctor to his companions. "Therefore, as I am determined not to travel by night, for fear of passing some stream or pool, we have but three days and a half of journeying during which we must find water, at all hazards. I have thought it my duty to make you aware of the real state of the case, as I have retained only one gallon for drinking, and we shall have to put ourselves on the shortest allowance."
"Put us on short allowance, then, doctor," responded Kennedy, "but we must not despair. We have three days left, you say?"
"Yes, my dear Dick!"
"Well, as grieving over the matter won't help us, in three days there will be time enough to decide upon what is to be done; in the meanwhile, let us redouble our vigilance!"
At their evening meal, the water was strictly measured out, and the brandy was increased in quantity in the punch they drank. But they had to be careful with the spirits, the latter being more likely to produce than to quench thirst.
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.