which was at a very low level. The height was scarcely 800 feet above the level of the sea. This circumstance gave the doctor some hope. He recalled the theories broached by geographers, respecting the existence of a vast expanse of water in the interior of Africa. But, if such a lake existed, they must arrive at it; still there was no change in the unruffled sky.
To a calm and starlit night succeeded a burning, stagnant day. From its earliest dawn, the temperature was broiling. At five o'clock in the morning the doctor gave the signal for departure, and for a long time the "Victoria" remained stationary in the leaden atmosphere.
The doctor had the power to escape this intense heat, by attaining a greater altitude, but to do this would necessitate the expenditure of a quantity of water, a thing now impossible. So he was constrained to maintain the balloon at a height of 100 feet, where a gentle breeze carried them towards the west. Breakfast consisted of dried meat and pemmican. At mid-day the "Victoria" had scarcely made any progress.
"We cannot go faster," said the doctor; "we do not command—we obey."
"Ah, my dear Samuel," said the Scot, "this is one of the occasions in which a propeller is not to be despised."
"No doubt, Dick, always admitting that it did not depend upon the action of water to move it, for in that case the position would be exactly similar. Up to the present time, however, nothing practical has been invented. Balloons are now at the point where ships were before the invention of steam. It took 6,000 years to bring out the paddle and the screw, so we have plenty of time to wait."
"Confound this heat," muttered Joe, wiping his forehead. "If we had sufficient water, this heat would do us good service, for it would expand the hydrogen, and we should not require so great a flame in the coil. It is true that, were we not at the end of our water-supply, we should not need to economize it. Ah! that cursed savage who obliged us to cast away that precious tank!"
"Do you regret what you have done, Samuel?"
"No, Dick, since we have been able to rescue that poor fellow from a horrible death. Yet the 100 lbs. of water which we cast away would have been very useful; there
