Then he had to reestablish the equilibrium of the balloon, and Joe was obliged to part with another considerable portion of his precious quartz. With restored health, his ambitious notions had come back to him, and he made more than one wry face before obeying his master; but the latter convinced him that he could not carry so considerable a weight with him through the air, and gave him his choice between the water and the gold. Joe hesitated no longer, but flung out the requisite quantity of his much-prized ore upon the sand. “The next people who come this way,” he remarked, “will be rather surprised to find a fortune in such a place.” “And suppose some learned traveller should come across these specimens, eh?” suggested Kennedy. “You may be certain, Dick, that they would take him by surprise, and that he would publish his astonishment in several folios; so that some day we shall hear of a wonderful deposit of gold-bearing quartz in the midst of the African sands!” “And Joe there, will be the cause of it all!” This idea of mystifying some learned sage tickled Joe hugely, and made him laugh. During the rest of the day the doctor vainly kept on the watch for a change of weather. The temperature rose, and, had it not been for the shade of the oasis, would have been insupportable. The thermometer marked a hundred and forty-nine degrees in the sun, and a veritable rain of fire filled the air. This was the most intense heat that they had yet noted. Joe arranged their bivouac for that evening, as he had done for the previous night; and during the watches kept by the doctor and Kennedy there was no fresh incident. But, toward three o’clock in the morning, while Joe was on guard, the temperature suddenly fell; the sky became overcast with clouds, and the darkness increased. “Turn out!” cried Joe, arousing his companions. “Turn out! Here’s the wind!” “At last!” exclaimed the doctor, eying the heavens. “But it is a storm! The balloon! Let us hasten to the balloon!” It was high time for them to reach it. The _Victoria_ was bending to the force of the hurricane, and dragging along the car, the latter grazing the sand. Had any portion of the ballast been accidentally thrown out, the balloon would have been swept away, and all hope of recovering it have been forever lost. But fleet-footed Joe put forth his utmost speed, and checked the car, while the balloon beat upon the sand, at the risk of being torn to pieces. The doctor, followed by Kennedy, leaped in, and lit his cylinder, while his companions threw out the superfluous ballast. The travellers took one last look at the trees of the oasis bowing to the force of the hurricane, and soon, catching the wind at two hundred feet above the ground, disappeared in the gloom. CHAPTER TWENTY-NINTH.