"There's speed, balance and strength for you. Where were they built?" The aviation chief explained. "Ah, I see," said the officer, "the paint only is ours. Well, I think we need look no further. Get them ready for immediate use. Where are the pilots for this assignment?" A call was passed for Billy and Henri. When they faced the official visitors, both of the latter turned a stare full of question marks at the aviation chief. "Are these the sons of our pilots to be?" The senior colonel meant to be a bit sarcastic. "No; but if the fathers really were as remarkably skilled in the high art of aëroplaning as 'the sons' you see here, I would request the general to let me go after them without delay." The airman was very much in earnest in his firm but respectful effort to correct the impression of his superiors in command that he had been guilty of some error of judgment. Henri unconsciously contributed another entering wedge when he gave his name to the younger of the colonels, who had taken a hand in the examination of the youthful candidates proposed by the aviation lieutenant for special aëroplane service. "Trouville!" exclaimed the officer; "are you of the house founded by the first François and the motto 'Sans Peur'?" (Without Fear.) "That's in my family record, sir," admitted Henri, who could not imagine what on earth his ancestry had to do with his ability to run an aëroplane. "Then you will find an open door in Petrograd," proclaimed the colonel, "that of my father, who in his day of travel was often a guest at the Château Trouville, when your grandfather lived and they were kindred spirits in the world of art." "Château Trouville and its art treasures are no more," sadly recalled Henri. "My father will mourn with you there," assured the colonel. Another assurance came from the aviation chief when the officers had returned to army headquarters to assist in the preparation of dispatches that were to go forward by aëroplane within the hour. Said the lieutenant: "It is settled, my flying friends, that you are to go on this journey, which is imperative, owing to the investment of railroad connections. The observers behind you will point out the route, and easy to follow, as the river is ever in sight. As to the rest, you need no instructions." "We are ready to start at the drop of a hat, sir," declared Billy. The boys had tuned the No. 3's to the point of perfection. The observers and dispatch bearers, Marovitch and Salisky, honor men in the service, soon appeared, hooded and enveloped in furs. The first named handed Henri a card. "From Colonel Malinkoff," he said. The boy saw that it contained the words "He is a Trouville," signed "Alexander," and directing to a certain street and number in Petrograd. Henri carefully pocketed the valuable reference.