"Some improvements and stronger motors added thought," said Blaine. "Going to give it a try-out?" "Yep! Thought I'd like to get my hand in a bit before we go out in squad formation." He nimbly vaulted into his seat over the rim of the fuselage, or the body of the machine, as two mechanics pushed forward behind the wings. An upward flip and the alert planes rose gently into the air, and Erwin was off. His head was cool, his brain active, and more than all his hands were steady. About this time Finzer had rolled out another plane and almost immediately rose behind Orris. The two were at once climbing high, higher, until at an elevation of two to three thousand feet they began to circle, climb and dip in a way that reminded one of two high-flying birds playing at tag far up in the blue expanse of sky above. Then Erwin's machine did a flip, bringing it above the other machine and "onto its tail," the favorable position for aerial attack. Suddenly Finzer turned his nose earthward and began a whirling dive. Erwin followed; the other coming at once into horizontal poise, turned his nose towards Erwin -- the perfect position for pouring a rain of shot as the other passed. Of course all this was mere practice, the full handed exercise of the fighting aviator, through which he keeps brain, eye and hand in trim against the perilous, heroic few seconds when he must fight to save his life and machine. Meantime Blaine, along with Brodno, the Americanized Pole, and one or two others, strolled about, lazily watching the maneuvers above, and telling stories more or less related to their and fighting experiences flying. Presently down came the two fliers, each with heightened color and full of that fresh buoyancy which short, lively flights are apt to create. Both were flippantly arguing as to which one had got the best of the other. "I own up that I am a little bit stale, Milt. But you wait until we go out for squadron practice. I'll show you!" "Yes, you will," replied Finzer, good-naturedly caustic. "Perhaps I'll show you another trick or two then." And so the chaffing went on as the lads adjourned to the eating-house for lunch. This meal over, a bugle sounded from the parade ground near the grove of trees. It was the general summons for squadron practice. As the boys filed out, each in full flying rig, they saw Commander Byers on the field, watching the mechanics roll out the machines. There were a dozen or more of the fighting planes, like those which Erwin and Finzer had used for morning practice. In the east, from over a monotonous expanse of scarred and war-torn country, came the sullen roar of artillery at the front, a stern reminder that real war was close at hand.