water. Thus it happens generally that the illusion is very different to one who is upon a camel, and to another who is upon the ground. H. I dare say it must be much like water since it deceives people so. But I think I should find it out if I saw it; because, sir, I should look for the shadows of the trees and houses, and such things as one sees in real water. U. O. In the open deserts, where the seraub is most frequently seen, you might not always find anything to give a shadow; but if there were, you would see the shadows all the same in the vapour as in real water. H. Indeed! U. O. Yes: and it is this which chiefly deceives people into the belief that it is water. That you may not think that it is only the ignorant and careless who can be deceived by it, I will read to you Dr. Clarke's description of the first seraub he ever saw. I have many times seen one under the same circumstances; but he describes it better than I can. Here is his description of the mirage:— "We perceived the domes and turrets of Rosetta, apparently upon the opposite side of an immense lake or sea that covered all the inter vening space between us and the city. Not having in my own mind at the time any doubts as to the certainty of its being water, and seeing the tall minarets and buildings of Rosetta, with all its groves of dates and sycamores as perfectly reflected by it as by a mirror, insomuch that even the minutest details of the architecture and of the trees might have been thence delineated, I applied to the Arabs to be informed in what manner we were to pass the water. Our interpreter, although a Greek, and therefore likely to have been informed of such a phenomenon, was as fully convinced as any of us that we were drawing near to the water's edge, and became indignant when the Arabs maintained that within an hour we should reach Rosetta by crossing the sands in the direct line we then pursued, and that there was no water. What!' said he, giving way to his impatience, do you suppose me an idiot to be persuaded contrary to the evidence of my senses?' The Arabs smiling soon satisfied him, and completely astonished the whole party, desiring us to look back upon the desert we had already passed, where we beheld a precisely similar appearance. It was, in fact, the mirage, a prodigy to which every one of us were then strangers, although it afterwards. became more familiar. The view of it afforded us ideas of the horrible despondency to which travellers must sometimes be exposed, who, in traversing the interminable desert, destitute of water, and perishing with thirst, have sometimes this deceitful prospect before their eyes." H. This is very curious indeed; and I wish I could see it. Is it to be seen no where but in Persia? U. O. Oh, yes! It is very common in Egypt and other parts of Africa, in Arabia, and some parts of Asiatic Turkey. Something like it has sometimes been seen on our own shores and those of France, but not with such strong powers of illusion as the true seraub possesses. An ordinary mist sometimes occasions a very remarkable illusion in Persia. It not only makes objects that are seen through it seem so much higher and taller than they really are, that a man who is seen upon the level plain at the distance of a mile and a half appears as tall as a ship's mast, but sometimes it changes in a very extraordinary manner the shapes of the things that are seen through it. As Colonel Johnson seems to have witnessed a stronger in stance than ever I did, I will tell you what he saw. As he was descending a height, he beheld in the valley below a mist which rose only a few yards above the ground; and beyond the valley he perceived, above the fog, the tops of high mountains, with rocky precipices, which seemed at no great distance. On descending slowly towards the mist, he observed a dark object in it, which resembled a distant village; but as he advanced it soon changed its aspect, and assumed that of a long avenue of trees, which seemed to open out as he approached. Colonel Johnson expressed his surprise to his friend at finding such fine trees in a desert where he did not expect to find a village, and in which they had before travelled for several miles without finding any trees at all; but in a few minutes it was found that the view was an illusion; and that the nearest objects in what had seemed the avenue had the appearance of camels with light burdens, on one of which a man was mounted. Afterwards, as they seemed to clear the fog, the objects proved, as it was then thought, to be mules laden with bags of grain, and men and |