Following the mechanic’s directions, the boys soon had the pieces resting at the proper distance apart on the cross-beams; and Jim, after considerable labor, succeeded in bolting them securely in place.

“Now for a couple o’ crosspieces,” he added, with a sigh of satisfaction.

“Solid as a rock,” declared the mechanic at length, testing the timbers with his foot. “Get the bed plate, an’ bolt it down.”

When this was done, the five took a well-earned rest; but it was for only a few moments.

“Now we’ll lower the engine into place, fellows,” said Jack, jumping to his feet.

By means of an inclined board and ropes, this was done; and Jim began to verify his previous measurements.

“I got the angle o’ the propeller shaft just right, lads,” he announced, holding a stick from the engine to a mark he had made on the stern-post. “The propeller o’ course has to be a sufficient distance below the water level.”

“Won’t be much pitch to that shaft, eh?” said Jack.

“No! I made it the least I could,” answered the mechanic, wiping his face. “Too much makes the boat lose speed.”

“I’ll bore the hole in the stern-post,” volunteered Jack.