But there were difficulties in the way. To take an escort of sufficient strength to resist possible enemy attacks, meant delaying the erection of the Palace for quite a considerable length of time. In addition, his personal supervision would be lacking, and mistakes might occur. Pondering over these and other matters, there one day flashed into his mind a rather quaint idea. Without any loss of time he sent for the Engineer Fairy; the one who had made the bamboo squares from which the water was sprayed when the Desert Fairies tried to fill the great Trench with sand. And this is what he said: “Hail! and greeting! O clever Engineer!” And the Engineer replied, “Hail! O Prince! Forever at your service!” “Engineer,” said the Prince, “I would that I could take a voyage through the air; and being seized with an idea, I have a mind to discuss it with thee. Listen then, O Engineer! and answer me in good time! As thou wert able to fill the hollow bamboo stalks with water—to the great undoing of our common enemy the Desert Fairies—canst thou not fill some others with air, and, having done so, construct me a carriage that might, like a bird, fly safely overhead?” As you may well believe, so unexpected a question could not be given an instant answer. It is doubtful indeed if the Prince himself expected any other than he got. What the Engineer Fairy said in reply was: “Permit, O Prince, thy servant time to think, and he will answer thee anon!” “Granted, most worthy Engineer!” said the Prince; “not until thou thyself do broach this matter again shall it be named betwixt us twain.” And the Prince rose in sign of dismissal. When the Engineer Fairy had time to think over the things the Prince had said to him he was greatly pleased at having been called “most worthy Engineer,” and he set about his novel task with the greatest good-will. Taking the hint given him by Prince Waratah, he got together a goodly number of bamboo stalks, most of them no thicker than a lady’s little finger. Carefully removing the inside pith, he first inserted a bark cork into the open end, and then covered it with a seal. The seals he used were made of hard brown gum-nuts; and in order that the bamboo tubes should be perfectly air-tight, he dipped their ends into hot melted beeswax before screwing on the cap-nuts. The effect was just the same as when hot paraffin wax is poured on top of a jar of newly made jam—nothing could either get out or in. Having in this way effectually sealed one end, he then, by means of a little electrical bellows, proceeded to fill the tubes with air, so full that they were almost ready to burst. But before that could happen, he deftly slipped a bark cork into position, swiftly dipped the unsealed end into the hot melted beeswax, and without losing an instant of time, rapidly screwed on the cap-nut, thus sealing that end as closely as the other.