The red scarf next. Would it call the suspended biplanes in swift swoop to the earth?
Skilled hands gripped the levers in readiness to instantly respond to the signal.
A cart with two muffled figures in it rumbled leisurely down the road. There was no urging of the sorry steed straining at its belled collar.
The biplanes perceptibly lowered, though it was merely guess work on the part of the aviators. The movement of the cart might have been just one of ordinary traffic, the occupants just plain, everyday peasants.
Suddenly the hovering airmen got a signal, but not the expected flash of scarlet. One of the carters, a big fellow, rose from his seat and frantically waved his arms, and the boys were then so near that they could plainly see that he varied the queer performance by pointing skyward with the long whip he was holding.
So intent had been the aviators in trailing the cart that they had neglected for a time to look elsewhere about them.
The gestures of apparent warning that they were witnessing returned their wits to normal, and what they had from the first low flight feared was about to be realized. Barely a half mile away, and buzzing toward them, were three aëroplanes, which, unnoticed by the otherwise engaged lads, had risen from the Russian camp.
Billy and Henri, now wholly confident that the antics that had awakened them to the impending peril were those of no other than Schneider, gave that good friend a parting salute of cap waving and turned about at full speed to lead a stern chase over and beyond the city—far beyond, it proved.
The pursuing biplanes, of the largest type, carried a crew of three men each, and that they had tremendous motor power was evidenced by their catapult coming.
But, light-weighted, the No. 3's were not to be easily overhauled. It must have been a contrary spirit that induced Billy and Henri to do other than head across the river to the German camp.