It was exactly four weeks later that the first of the planes had been assembled ready to roll out of the hangar for the final adjustments and tuning up. The ships were of the two-seater type, similar to the JN4H’s so commonly used on American flying-fields, and of sturdy, dependable construction. They had two-hundred-horse-power eight-cylinder engines, and were rated as capable of making an air-speed of ninety miles an hour. There were radio sets and machine-guns, the latter mounted one above the engine and the other on a turret in the rear cockpit. Ted and Stanley surveyed their work with pride. The motor roared with an even, steady purr, or snorted and banged as the mechanician opened and closed the throttle, while the graceful machine tugged impatiently in its efforts to free itself from the grasp of the men clinging to the wings, and to leap the blocks that had been placed under the wheels. “When shall we take the first spin?” Ted asked as he inspected the turnbuckles and hit the wire braces with his hand to gauge their tautness. “To-morrow, if nothing goes wrong. Think of what a wonderful experience it will be to soar over the peaks of the Andes; and the first chance we get we will hop off to the Valley. All our dreaming and planning is about to bear fruit.” Just then the colonel accompanied by two officers in strange uniforms approached. The colonel introduced the new arrivals to the Americans. “At last they are here,” he added. “They will have entire charge of the cadets. You gentlemen will work together in perfect harmony, I hope, in the best interests of the service.” Ted and Stanley showed genuine pleasure at making the acquaintance of the two lieutenants, but the latter seemed cool and reserved, and after a casual examination of the throbbing ship followed the colonel into one of the hangars. A moment later Ted went to the rear of the structure to get a wrench from the tool-box, and while pawing through the miscellaneous collection the chest contained, the sound of voices from within reached his ears. “I have investigated them thoroughly,” the colonel was saying, “and I have learned that they have been in Cuzco at least twice before this. Each time they disappeared on some secret mission into the mountains, and it is said that they are searching for a lost mine or hidden treasure. But that is nothing against them; we should do the same if we had a reason to hope for success in such a venture. I have also examined their pilot’s books, for which they cabled voluntarily, and they showed an unusually large number of hours in the air and a record above reproach. Their work here has been done well. And, besides, they came to my assistance when I needed them. I sent for them; they did not beg me for the places.” “If the colonel will pardon my saying so, the lieutenant and I can now assume full charge of the work. We do not need the Americans. We ourselves should supervise the rigging of the ships we are to fly.”