It was, indeed, as they soon found. The two cylinders which had been cracked by the flying wrench were in the centre of the motor. To get them out it was necessary to uncouple a number of pipes, cams, gears and wires. Fortunately there were the necessary tools on board, and all three of the lads had had considerable experience in machine work. But, even with all this, they were all day getting the two cylinders out.
“Now,” announced Jerry, “it remains to be seen whether we can connect up the other eight, and use the water-cooling system to good advantage,” for the motor was not an air-cooled one. “We’re going to have trouble connecting the water pipes,” he predicted, as he wiped the perspiration from his face.
It had been hard work—doubly so under the broiling sun of the desert. At noon Nestor and Tod had returned, but it did not need a negative nod of Nestor’s head to tell Jerry that their quest for water had been unsuccessful. They set off again in the afternoon. Professor Snodgrass had not come back to lunch, but there was nothing remarkable in this. Often in his search for a curious insect he had been known to go all day without food, and he never minded it.
Late that afternoon, while Ned and Bob were toiling away, helping Jerry, Bob went to the water tank, and, after taking a big drink, he threw away what liquid remained in the glass.
“Don’t do that!” exclaimed Jerry quickly.
“Why not?”
“Because we might need it. No telling how long we will be here, and water doesn’t grow on every bush.” He tried to speak lightly, but Ned and Bob must have guessed what he meant, for after that it was observed that both took very small drinks.
After a restless night spent in the airship, the professor having returned just before dark, the boys started in the next day to connect up the eight good cylinders. They found it a harder task than even Jerry had anticipated. All day they hammered, bored and filed metal. They made fitting after fitting, only to discover a leak, and then they had to do it all over again. They toiled until the perspiration of their hands and faces, mingling with the grease and grime, made them look like foundrymen. But they did not give up. After several failures, Jerry remarked:
“Say, let’s knock off a bit and take a walk over the desert. It will rest us, and we can work better when we come back.”
“What? Walk in that broiling sun?” asked Bob, shaking some drops of perspiration from the end of his fat nose.