The scene was one of such extravagance that the brain was staggered with what the eye tried to register.  Below the aviators, the shadow of their machine pursued them on white film like a grotesque gray bird of some supernatural region.  The shadow followed tirelessly, gaining as the hour of noon approached, gaining still as afternoon began to gather, swell, and wane; and always it skipped from crest to crest down there just below, jumping gulfs like a bewitched phantom.