Every flyer who ventures across oceans to distant lands is a potential explorer; in his or her breast burns the same fire that urged the adventurers of old to set forth in their sailing-ships for foreign lands. Riding through the air on silver wings instead of sailing the seas with white wings, he must steer his own course, for the air is uncharted, and he must therefore explore for himself the strange eddies and currents of the ever-changing sky in its many moods.