Almost at once the two naturalists grasped the meaning of Joe’s misfortune.
“There’s no doubt about it,” began Mr. Wallace, who was himself becoming pale. “You have mountain sickness, or soroche, as it’s called. I think I have a touch of it myself.”
“What causes it?” queried Bob.
“The high altitude,” Mr. Holton answered. “You see, when one makes a sudden change to nearly eleven thousand feet, it is a great strain on him. Usually, though, it doesn’t show up until reaching a much higher altitude than this. I’m surprised that Joe has it so soon.”
Joe did not become worse, but grew no better. One thing was apparent: until he would show improvement, he could not continue the journey.
Mr. Holton and Bob helped him into the cabin of the airplane, where an improvised bed was made.
“If it’s all right, I think I’ll stay with him,” announced Mr. Wallace. “I’m not feeling any too well myself, and then, too, Joe ought to have someone here with him.”
“All right,” said Karl. “Meanwhile the rest of us will go on into the city and have some gasoline sent out to the ’plane.”
In Quito the others found a filling station, the operator of which agreed to send out a truck to the monoplane to fill the tanks.
Back at the field they found that Joe had greatly improved and was anxious to fly on to Lima. It was evident that he had had only a slight attack.