"Full speed ahead!" cried out Mr. Hume.

Venning pulled his lever over, and as he shot it back Compton pulled
his, the two moving to and fro easily as if they had been rowing a
steady stroke.

"She moves, she moves!" cried Mr. Hume, with a shout.

"Take her over the mile," said the designer to the steersman; and he
pulled out his watch with exactly the same look of calm interest he
showed when presiding over the trial of the fastest craft afloat.

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!"