"Dalzell's map-work at Annapolis was good enough to suit any need around here, and I shall be glad to see Dalzell get the chance."
"On that showing," returned Trent, "Darrin shall have the chance if it comes this way."
After a quick meal the detachment was under way. In about an hour the position ordered had been taken.
"Here comes the first Navy birdman!" cried Dan suddenly, pointing townward.
Just appearing over the housetops, and soaring to an elevation of a thousand feet, came one of the huge hydro-aeroplanes in which Navy aviators had long been practicing for just such work as this. Capable of coming down and resting on the water, or of rising from the same, these aircraft were ideally suited to the work. Swiftly over Vera Cruz came the airship, then straight out over the advanced line, and next on toward the detachment beyond.
"He isn't coming down," cried Danny Grin in a tone of genuine disappointment. "No chance for you on that one, Davy! Too bad!"
Yet suddenly the rattling noise nearly overhead almost ceased as the engine was shut off. Then gracefully the craft voloplaned and touched the ground, just inside the detachment's line.
"Great work, Bowers!" cried Trent, recognizing in the Navy birdman a former classmate at Annapolis.
"Thank you, Trent. You have an officer, haven't you, to help me with field notes on this survey?"
"I have two," smiled Trent, "but I am afraid I can spare only one. Lieutenant Bowers, Ensign Darrin. Hop aboard, Darrin!"