"We certainly agree to that condition, Major Nixon," said Frank heartily. "In fact, I should have asked that one be sent out with us. It is a part of our policy to fully satisfy the authorities we've been dealing with for nearly a year, now, that everything we claim, and much more, is possible with our advanced model of a hydro-aëroplane."
"Very good, and I am pleased to know it," said the officer. "I shall have to go back to town, now, but I will advise the local representative of the Government that you accept the conditions. By early dawn there will appear here a skillful aviator with written credentials, and I hope his ultimate report will be all you boys hoped it to be. My word! I only wish I were going with you, but other duties must claim my attention."
He shook each one of them warmly by the hand.
"The best of luck, Frank," were his last words at parting. "I trust that you may have an experience calculated to dwarf anything that has ever come your way."
Frank, as he contemplated what a thrilling adventure lay before them, fancied that this wish on the part of Major Nixon was in a fair way of coming true. It certainly would be difficult to imagine a more exciting experience than taking part in an aërial raid, where more than thirty seaplanes started out to bombard strongly fortified coast defenses of the enemy, each raider subjected to a continual fire from every known species of anti-aircraft gun known to modern warfare.
After the soldier had left them, the three Boy Aviators sat around and talked in low tones. They had barred the door, and so far as they could see there was not the slightest chance that any eavesdropper could get close enough to overhear what they said. Nevertheless, the caution of Major Nixon had its effect upon them and there was no loud conversation except when ordinary matters were touched upon.
Frank always liked to "potter" around and give little touches of improvement to some part of the seaplane in which he had such a deep interest. No one knew its good and bad qualities as well as Frank; even its inventor had not studied these points as carefully as the young aviator.
So it happened that from time to time the boy made numerous little improvements that he figured would cause the motors to work more smoothly, or strengthen some part of the framework that showed signs of weakness.