One day, however, Frank noticed that the center casting on No. 33 was broken in such a way that but one bolt held it at all, and that very slightly.

He supposed, of course, that the engineer had reported it, and he expected every minute to see the men come along with the jacks and jack her up to put in a new one.

Though there was a king pin down through both castings, it would be suicidal for a man to trust that alone. In rounding a curve the engine would be apt to sheer off and shoot off the track at a tangent.

Frank was surprised as the time approached for old 33 to leave the house and no attempt had been made to repair her. Then he hunted up Mr. Ganzell and reported what he had discovered.

Ganzell seemed doubtful.

“Come with me,” he said, and together they went round the house to the hook on which the machinists hung the engineer’s work reports after jobs were finished.

He looked the report over and found 33’s.

“It’s O. K.’d,” he said. “Not a word about the center casting. You must be mistaken, Mr. Merriwell.”

“I am sure I am not, sir,” declared Frank.

“Well, I will investigate. Come.”