"This is what is called a mirage, then?" said Frank. "I've often heard of it, and longed to see it; and it is a more extraordinary delusion than I could have supposed possible. Why that low line of rock there, and those dwarf shrubs looked as if they were at least sixty feet high. How in the world do you account for it, Mr Lavie? Why even Lion was taken in!" "I am afraid I cannot give you an explanation, which you will understand very clearly, Frank. It is caused by the inequality of the temperature in the lower strata of the air; which again is the result of the reflected heat of the sun's rays on the barren, sandy plain. While the strata are unequally heated, these curious reflections, which are like those seen in broken mirrors, continue to deceive the eye. Objects appear to be raised high into the air, which in reality are to be found on the surface of the earth, often too they are immensely magnified, as indeed you saw just now; a single stone will seem the size of a house, and an insignificant shrub look as big as a forest tree. But when the sun gains sufficient power to raise all the strata to a uniform heat, the mirage melts away." "But your shot seemed to disperse it just now." "So it did. But my shot only disturbed the strata; and if the mirage had not been nearly on the point of vanishing, from the increasing solar heat, I doubt whether the same effect would have followed. But it is time for us to go back to our hut and finish our work. Nick, I suppose you will join us? We may see pretty plainly for ourselves that there are no fishermen's huts in this quarter." Nick assented, and the three, after a short rest under the shade of the rocks, returned to the spot whence they had set out, and resumed their work. By two o'clock the two uprights were fixed in the sand, and in two hours afterwards the tent was complete. All the stores were then carefully conveyed inside, the keg of gunpowder being buried in the sand to prevent the possibility of accident. Then the two lads set about preparations for supper, which was to consist, like that of the morning, of fish broiled on the embers. "And a very good supper too," observed Nick; "I don't think I ever ate a finer fish than this cod here." "It's first-rate, there's no doubt of that," returned Frank; "but I must own I should like something besides. I suppose your flamingo there wouldn't be very good eating?" "I expect not," replied Lavie. "The flamingo is too gross a feeder to make very good food itself. One might eat it, I dare say, if there was nothing else to be had. I have eaten lion steaks once in my life, but I have no ambition to repeat the experiment. No, I don't propose to make any further use of my flamingo than to cut off one of his beautiful red wings to make a fan of, and hand the rest of the bird over to Lion. What a splendid-looking bird he was; it really seems almost a shame to kill him!"