pointed out how impossible it was to raise such a weight. It was a choice between water and ore. Joe hesitated no longer, and cast away upon the sand a quantity of his beloved pebbles.
"They will serve for those who follow us," he said. "They will be very much astonished to find a fortune in such a place."
"Suppose," said Kennedy, "that some learned traveler should meet with these specimens?"
"No doubt he would be very much surprised, my dear Dick, and would equally publish his surprise. Some day we shall hear of a wonderful deposit of auriferous quartz in the midst of the sandy desert of Africa."
"And Joe will have been the cause."
The idea of mystifying some learned professor somewhat consoled this brave lad, and he smiled.
During the remainder of the day the doctor watched in vain for a change in the sky—the heat became greater, and without the shade of the oasis would have been intolerable. The thermometer in the sun marked 149°. A regular rain of fiery rays traversed the air. This was the greatest heat they had yet noted.
Towards evening Joe prepared the watch-fires, and during the vigils of the doctor and Kennedy nothing particular occurred. But towards three in the morning—Joe was watching—the temperature fell suddenly, the sky became obscured, and the darkness increased. "Get up!" cried Joe, waking his companions; "get up—the wind is coming!"
"At last!" cried the doctor, looking up at the sky.
"It is a regular storm! To the balloon—to the 'Victoria!'"
They were only just in time. The "Victoria" was bending beneath the force of the storm, and was dragging the car across the sand. Had any part of the ballast been out of her the balloon would have sailed away, and then all hope of regaining her would have been lost.
But Joe, quick as ever, ran as hard as he could and stopped the car, while the balloon beat along the sand, at the risk of being torn to pieces. The doctor took his usual place, lighted up the blow-pipe, and threw out the excess weight.
