For a long time, invisible and mysterious, it had been describing its great circles deep in the concealing vapors that hid it from the earth and hid the earth from it.

Lady Barbara Collis was worried. Her petrol was running low. At the crucial moment her compass had failed her, and she had been flying blind through the clouds looking for an opening for what now seemed an eternity of hours to her.

She had known that she must cross a lofty range of mountains, and she had kept at a considerable altitude above the clouds for this purpose; but presently they had risen to such heights that she could not surmount them; and, foolishly, rather than turn back and give up her projected non-stop flight from Cairo to the Cape, she had risked all in one effort to penetrate them.

For an hour Lady Barbara had been indulging in considerable high powered thinking, intermingled with the regret that she had not started thinking a little more heavily before she had taken off, as she had, against the explicit command of her sire. To say that she was terrified in the sense that fear bad impaired any of her faculties would not be true. However, she was a girl of keen intelligence, fully competent to understand the grave danger of her situation; and when there loomed suddenly close to the tip of her left wing a granite escarpment that was lost immediately above and below her in the all enveloping vapor, it is no reflection upon her courage that she involuntarily caught her breath in a quick gasp and simultaneously turned the nose of her ship upwards until her altimeter registered an altitude that she knew must be far higher than the loftiest peak that reared its head above any part of Africa.