“No doubt of it,” was the response.

And indeed this would have been plain even to the most inexperienced eye. One of the grooves cut in the piston to receive a compression ring was packed with broken bits of metal and metallic dust, many of the fragments having actually been reduced to powder.

“That’s a bad job,” remarked Walter, shaking his head. “I wonder if the cylinder itself is damaged much.”

“Easy to find out,” said Jack. “Let’s have a look.”

They were relieved to find that the cylinder was very little scored, considering the condition of the piston.

“Looks to me as if a new set of piston rings would be necessary,” judged Paul.

“That’s what,” replied Jack. “But it would probably take a week to get them from the manufacturers.”

Cora gave a little exclamation of dismay.

“And wait all that time before we can have a ride in the Water Sprite?” she asked.

“Unless you can wave a magic wand and make the pistons come running,” said Jack.