return Cadet Captain Prescott, after a swift, astonished look at
his classmate.

"You know I can't do that," muttered Cadet Jordan. "But you-----"

"Silence, sir, and attend to your duty!"

Then, raising his voice to one of general command, Prescott called:

"Construct the bridge!"

Jordan fell back, with a surly face and a muttered imprecation, to
take command of the squad of yearlings, or third classman who must
serve in carrying the heavy balks.

In the meantime Dick's roommate, Greg Holmes, had hurried his
squad away to the flat-bottomed, square-ended pontoon boats, placing
his crews therein.

Almost instantly, it seemed, Greg had placed the first boat in
position.

"Lay the balks!" ordered Dick Prescott.

Cadet Jordan moved forward with some of his yearlings, who carried
the heavy balks, or flooring timbers, on their shoulders. It was
hot, hard work---"thankless," as the young men often termed it in
private.

These balks were laid across the first pontoon.