The faces of some were expressionless, but a few shook their heads.

“We do not use gasoline here,” one man said in the native tongue. “There are no great birds like this”—pointing to the monoplane—“in our land. And we have no carriages that are not drawn by animals.”

Mr. Holton then asked if it might be possible to get gasoline in Cartagena, the city on the coast.

Strange to say, the people did not know. Evidently they had never been to that place, although it was less than fifty miles distant.

“Well, then,” began Karl, “I suppose one of us will have to take a train to Cartagena. Whoever goes can take a gasoline can with him and get it filled. Then he can return on the next train.” The Americans could not help laughing at this, however necessary it might have been. The idea of boarding a train for a fifty-mile journey merely to get a can filled with gas seemed provoking.

“What a predicament!” roared Bob, catching hold of the monoplane in order to hold his balance.

“I suppose we ought to take this more seriously,” said Karl, who was also laughing. “But somehow it all seems humorous to me.”

At sight of the Americans laughing, the crowd of natives looked about sullenly. No doubt they thought the newcomers were making fun of them. Finally one man stepped up to Bob, and, with a sneer, uttered something in the native language.

The youth could only catch a word or two, but it was enough to make him glare at the man in anger.

“Be careful, Bob,” warned his father. “There are too many of them for us to get into a scrap.”