The day passed away and as the sun was going down a most serious accident occurred to the engine.
Frank noticed a tremendous rattling sound at the end of the driving wheel shaft.
He made his way to the stern.
There he observed that the noise came from the smallest of the two screws at the extreme end.
The nut that held it on the shaft had worked loose.
Intending to stop the machinery and tighten the nut Frank was just about to walk away to get a wrench when there sounded a harsh, grating noise.
The wheel suddenly flew off the shaft.
Spinning around and around it dropped down into the sea into which it sank and disappeared.
A cry of vexation escaped Frank.
He did not have another wheel on board and had no means of getting another.