“What’s the matter?” exclaimed the stout youth in alarm.

“I don’t know,” was Oliver’s reply. “Something wrong ahead, I suppose.”

“Perhaps part of the roadbed has sunk,” suggested Mr. Whyland, who sat on the other side of the aisle. “I understand such a thing frequently occurs here.”

They all sat quiet for ten minutes. By this time one and another of the passengers began to get out, and finally the three joined them, and walked up to where the engine stood, blowing off steam.

Mr. Whyland’s surmise proved correct. Not fifty feet distant the rails of the road were submerged in a murky pool of foul-smelling water. The length of the depression was about one hundred feet, and its greatest depth a foot and a half.

Already a gang of native laborers were at work repairing the damage. There were a dozen or more of them, but they worked so slowly that hardly any progress was made.

“Seems to me if I was overseer here I would hurry those men up,” remarked Gus, after they had watched the proceedings for some time.

“They cannot hurry much,” said Mr. Whyland. “The climate is against them. I doubt if you could stand the work more than an hour. Come, let us get away from that pool. It is a regular hotbed of fever.”

“I wonder how long this will delay us?” said Oliver, as they walked back to the car.