Steering over the placid surface of the Mediterranean Joe Gresson and his friends hovered over the port of Alexandria, and thence sailed for Cairo. Shrill cries greeted her from the sandy desert about the ancient pyramids, while a motley crowd waved to her from their summits. But there was no time to halt. With one long look at the placid, cruel, yet gentle face of the sphinx the ship's head was swung towards the east. An hour later a long ribbon of blue, shimmering in the sun, and hedged on either side by an unbroken expanse of yellow, told of the great Suez Canal. "We'll follow it through its length," said Joe, now at the helm. "See! We are seven thousand feet up, and one can perceive a huge portion of the canal, severed here and there by the bitter lakes through which it runs. Ah! There's a ship. Let's drop down close to her." The vessel plunged. One who was ignorant of her powers would have imagined that she was about to crash to the ground. But she was merely descending at her fastest pace, and plunging brought her within hailing distance of the ship then passing through the canal, even before Mr. Reitberg had quite recovered his nerve or his equilibrium. "_Himmel!_" he shrieked, as the vessel headed downward and shot toward the sand. "Hold her! She is falling! We shall all be killed." He formed the mad resolution of rushing to the engine-room, and stepped in that direction. But, as we have said, the inclination of the decks considerably upset his equilibrium. The magnate indeed took a header, slithered along the smooth platform beneath the gas chambers, and landed up against one of the partitions with a bang which shook his eyeglass from its holding. By then the vessel was within a hundred feet of the canal, sailing along directly over it, and just ahead of the ship ploughing her way through the water. What cheers there were! How the passengers on that eastward-bound vessel crowded the decks and shouted! And then the liner hoisted her Union Jack, and dipped it formally. At once the watchful Hawkins responded from the deck above, while again cheers came to the ears of Dick and his friends. "And just contrast the two ships," said Alec, when they had progressed in this fashion for perhaps an hour. "Look! You can see the airship's reflection in the water, and, my! ain't she a whopper!" Yes, she was huge, vast, incredibly enormous. And yet how smoothly she sailed along, and with what little effort! It was a fascinating picture to behold. Dick found himself following the giant outline, picking out the various points till then invisible from the deck above, or from the platforms below. For instance, four huge attachments puzzled him immensely, for they hung from the framework and seemed without purpose.