The shining aluminium boat answered to her helm, slipped through the muddy waters in a graceful curve, and then steadied for the straight course.

"Let her go, boys."

The levers worked to and fro with an easy swing; there rose the hum of the chains moving easily below, and the quickened churning of the propeller blades.

The designer glanced from his watch to the bank, which was fast slipping away, and nodded his head at Mr. Hume.

"Easy all. I think she will do;" and he nodded at Venning. "Ten minutes."

"Ten minutes!"

"A mile in ten minutes—six miles an hour!"

"And it was as easy as nothing," said Venning—"wasn't it, Dick?"

"Like cutting bread," said Compton.

"Very good, I think; but you must remember that she carries no cargo. Now we'll try her with the sail alone, and then with the sail and screw combined, and then with the screw and oars, for you will see that I have fitted row-locks."